Information
-
Patent Grant
-
6362793
-
Patent Number
6,362,793
-
Date Filed
Monday, August 7, 200024 years ago
-
Date Issued
Tuesday, March 26, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 343 702
- 343 895
- 343 725
- 343 729
- 343 850
- 343 853
- 343 852
- 343 859
- 343 860
- 343 865
-
International Classifications
-
-
Disclaimer
Terminal disclaimer
Abstract
An antenna in which first and second antenna elements are selected by a switching apparatus so that the first and the second antenna elements are connected to an unbalanced transmission line via a balancing-unbalancing transmission line or only the first antenna element is connected to the unbalanced transmission line. The unbalanced transmission line supplies power via a balanced-to-unbalanced transformation apparatus to the first and the second antenna elements, so as to operate as an antenna, at which time, balanced-to-unbalanced transformation action of the balanced-to-unbalanced transformation apparatus prevents leakage current from flowing from the first or the second antenna element to the unbalanced transmission line and prevents a ground element on which the unbalanced transmission line is grounded from operating as an antenna. This reduces deterioration of antenna characteristics in the vicinity of a human body, so that an antenna device and portable radio set which can sizably reduce deterioration of communication quality can be realized.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an antenna device and a portable radio set, and more particularly, is suitably applied to those such as a cellular telephone, etc.
2. Description of the Related Art
The cellular telephone of this type has been decreased in size and weight so far in order to improve the portability. Thereby, a retracting/pulling out type of whip antenna device is positively developed as an antenna device provided for a cellular telephone. There is a cellular telephone configured as shown in
FIGS. 1A and 1B
as the cellular telephone of the above type.
In case of a cellular telephone
1
having the above configuration, a retracting/pulling out type of whip antenna device
3
is provided for a housing
2
made of a non-conductive member such as synthetic resin.
The antenna device
3
has an antenna section
6
provided with a rod antenna
4
made of a conductive wire rod and a helical antenna
5
formed by helically winding a conductive wire rod. The antenna section is set so as to be freely retracted and pulled out along a direction in which the antenna section
6
is pushed into the housing
2
shown by an arrow a at the upper end
2
A of the housing
2
(this direction is hereafter referred to as retracting direction) and inversely, along a direction in which the section
6
is pulled out of the housing
2
(this direction is hereafter referred to as pull-out direction).
In the antenna section
6
, a first power-supply member
7
made of a conductive member and having a protrusion
7
A is electrically and mechanically connected to the lower end of the rod antenna
4
and a connecting portion
8
made of a non-conductive member is mechanically connected to the upper end of the rod antenna
4
.
Moreover, a second power-supply member
9
made of a conductive member is electrically and mechanically connected to the lower end of the helical antenna
5
and mechanically connected to the connecting portion
8
. Thereby, in the antenna section
6
, the rod antenna
4
and the helical antenna
5
are mechanically connected each other by the connecting portion
8
but they are electrically separated from each other.
Moreover, the rod antenna
4
is covered with an antenna cover for the rod
10
and the helical antenna
5
is stored in a cap-shaped antenna cover for the helical
11
so that the antennas
4
and
5
do not directly contact a user.
A circuit substrate (not illustrated) on which various circuit devices including a transmission-reception circuit
12
and a matching circuit
13
are mounted and a shielding case serving as a ground member made of a conductive member for covering the circuit substrate are stored in the housing
2
.
Moreover, an antenna power-supply terminal
14
made of a conductive member electrically connected to the matching circuit
13
is set inside of the upper end
2
A of the housing
2
and only either of the rod antenna
4
and helical antenna
5
is electrically connected to the antenna power-supply terminal
14
when the antenna section
6
is retracted or pulled out.
Actually, in the antenna device
3
, the antenna cover for the helical
11
is pushed in the retracting direction and made to contact the upper end
2
A of the housing
2
to push the rod antenna
4
into the housing
2
and retract the rod antenna
4
in the housing
2
and electrically connect the second power-supply member
9
to the antenna power-supply terminal
14
.
In addition, in this antenna device
3
, under this state, the transmission-reception circuit
12
supplies the helical antenna
5
with power sequentially via the matching circuit
13
, the antenna power supply terminal
14
and the second power supply member
9
so as to operate this helical antenna
5
as an antenna.
In addition, in this antenna device
3
, at this time the rod antenna
4
is electrically separated from the antenna power supply terminal
14
by the connection section
8
so that it will not operate as an antenna.
On the other hand, in the antenna device
3
, when the second antenna cover
11
is pulled in the direction to be pulled out under the state that the rod antenna
4
is retracted inside the housing
2
, the rod antenna
4
is pulled toward outside from the upend
2
A of this housing
2
and then the protrusion
7
A of the first power supply member
7
is thrust onto the antenna power supply terminal
14
to bring this first power supply member
7
into electrical connection with the antenna power supply terminal
14
.
In addition, in this antenna device
3
, the transmission-reception circuit
12
supplies the rod antenna
4
with power sequentially via the matching circuit
13
, the antenna power supply terminal, and the first power supply member
7
so as to operate this helical antenna
4
as an antenna.
Furthermore, in the antenna device
3
, by electrically separating the helical antenna
5
from the antenna power-supply terminal
14
by the connecting portion
8
, the antenna
5
is not operated as an antenna.
In this connection, to make the rod antenna
4
and helical antenna
5
operate as antennas, the impedances of the rod antenna
4
and helical antenna
5
are matched with the impedance of the unbalanced transmission line
16
by the matching circuit
13
.
Moreover, the shielding case functions as ground for various circuit devices and moreover functions as an electrical shielding plate for preventing radio waves of external noise and radio waves emitted from the antenna section
6
from entering various circuit devices mounted on a circuit substrate.
Thereby, the cellular telephone
1
makes it possible to, at the time of pulling out the antenna section
6
, transmit a transmission signal configured of a high-frequency signal from the transmission-reception circuit
12
to the rod antenna
4
through the matching circuit
13
, transmit the transmission signal to a base station (not illustrated) through the rod antenna
4
, and transmit a reception signal configured of a high-frequency signal transmitted from the base station and received by the rod antenna
4
to the transmission-reception circuit
12
through the matching circuit
13
.
Moreover, the cellular telephone
1
makes it possible to prevent the portability of the rod antenna
4
from damaging by retracting the antenna
4
in the housing
2
at the time of retracting the antenna section
6
, transmit a transmission signal from the transmission-reception circuit
12
to the helical antenna
5
through the matching circuit
13
under the above state, transmit the transmission signal to a base station through the helical antenna
5
, and transmit a reception signal transmitted from the base station and received by the helical antenna
5
to the transmission-reception circuit
12
through the matching circuit
13
.
Incidentally, in such a cellular telephone
1
, multi-path phasing could take place when signals transmitted from a base station are received. Thus, as such a cellular telephone there is the one that is provided with an antenna device of a diversity reception system.
Here,
FIG. 2
shows a basic configuration of the antenna device
15
of a diversity reception system, and for reception two antenna elements
16
and
17
, for example, are provided, and these antenna elements
16
and
17
are brought into electrical connection with the switch
20
via the matching circuits
18
and
19
respectively, and the switch
20
is electrically connected with the reception circuit (not shown).
In addition, in this antenna device
15
, the levels of the reception signals received by these two antenna elements
16
and
17
periodically are compared, and based on the result of this comparison, the switch
20
undergoes switch control to switch the antenna element
16
or
17
to be used for reception. Thus, the reception signal with a high level is selectively received so that multi-path phasing is reduced.
Incidentally,
FIG. 3A
as well as
3
B where the same symbols for parts as in
FIG. 1A
as well as
1
B corresponds each other shows a cellular telephone
22
which is provided with an antenna device
21
of a diversity reception system.
Such an antenna device
21
has a predetermined built-in antenna
23
disposed inside the housing
27
, and this built-in antenna
23
is brought into electrical connection with the matching circuit
24
.
This matching circuit
24
is brought into electrical connection with the switch
25
together with the matching circuit
13
to be brought into electrical connection with the antenna section
6
, and this switch
25
is brought into connection with electrical connection with the transmission-reception circuit
12
.
In addition, in this antenna device
21
, a rod antenna
4
and a helical antenna
5
of the antenna section
6
are used as an antenna element for the dual use of transmission and reception, and the switch
25
undergoes switching control so that a built-in antenna
23
is used as the antenna element to be exclusively used for reception, and thus the transmission-reception circuit
12
is brought into electrical connection with the antenna section
6
at the time of transmission and the transmission-reception circuit
12
is brought into electrical connection with either the antenna section
6
or the built-in antenna
23
at the time of reception.
Thus, in a cellular telephone
22
, the transmission signals are transmitted from the transmission-reception circuit
12
to the rod antenna
4
or the helical antenna
5
sequentially via the switch
25
and the matching circuit
13
, and thereby these transmission signals are sent to the base station via the rod antenna
4
or the helical antenna
5
.
In addition, in the cellular telephone
22
, at the time of reception, the switch
25
rapidly undergoes switching control so that the reception signals received by the rod antenna
4
or the helical antenna
5
are transmitted to the transmission-reception circuit
12
sequentially via the matching circuit
13
and the switch
25
, and the reception signals received by the built-in antenna
23
are transmitted to the transmission-reception circuit
12
sequentially via the matching circuit
24
and the switch
25
so that the levels between these reception signals are compared.
In addition, in this cellular telephone
22
, when the level of reception signals received by the rod antenna
4
or the helical antenna
5
is high, the rod antenna
4
or the helical antenna
5
is brought into electrical connection with the transmission-reception circuit
12
via the switch
25
, and when the level of reception signals received by the built-in antenna
23
is high, the built-in antenna
23
is brought into electrical connection with the transmission-reception circuit
12
via the switch
25
.
Thereby, in the cellular telephone
22
, at the time of reception, the reception signals received by the rod antenna
4
or the helical antenna
5
are transmitted to the transmission-reception circuit
12
sequentially via the matching circuit
13
as well as the switch
25
, or the reception signals received by the built-in antenna
23
are transmitted to the transmission-reception circuit
12
sequentially via the matching circuit
13
as well as the switch
25
.
Thus, in this cellular telephone
22
, an antenna element of either any of the rod antenna
4
or the helical antenna
5
and the built-in antenna
23
is used so as to selectively receive reception signals with a high level and thus reduce multi-path phasing.
Incidentally, cellular telephones
1
and
22
in such a configuration are provided with, for example, an unbalanced transmission line
26
being configured by comprising a micro-strip line formed in a circuit substrate, and the transmission-reception circuit
12
is brought into electrical connection with the rod antenna
4
, the helical antenna
5
or the built-in antenna
23
via the hot side of this unbalanced transmission line
26
, and in addition, the ground side of this unbalanced transmission line
26
is grounded to the shield case.
In addition, in the cellular telephone
1
and
22
, as shown in
FIGS. 4A
to
4
C, the transmission-reception circuit
12
supplies the rod antenna
4
, the helical antenna
5
or the built-in antenna
23
with power via the hot side of the unbalanced transmission line
26
so as to bring these rod antenna
4
, helical antenna
5
, or built-in antenna
23
into operation as an antenna, and then from the ground side of this unbalanced transmission line
26
, the leakage current i
1
flows into the shield case
27
which is approximately same potential with this so as to bring this shield case
27
into operation as an antenna as well.
But, in such cellular telephones
1
and
22
, with any of the rod antenna
4
, the helical antenna
5
, and the built-in antenna
23
being thus brought into operation as an antenna, the shield case
27
operates as an antenna, and therefore a hand of a user grabbing the housing
2
, which covers the shield case
27
via this housing
2
, gives rise to a problem that the antenna characteristics of the cellular telephones
1
and
22
are deteriorated.
In addition, when the shield case
27
is operating as an antenna, the housing
2
, which is grabbed by the user's hand, approaches his/her head, and then this head will further cover the shield case
27
via the housing
2
, and therefore the antenna characteristics of the cellular telephones
1
and
22
are further deteriorated, thus giving rise to a problem that the communication quality over telephones is deteriorated.
Moreover, the shield case
27
, which operates as an antenna for transmission, radiates a power, and at that time a hand or the head of a user, which approaches the shield case, gives rise to a problem that the power per unit time and unit mass to be absorbed by a specific portion in a human body (so called Specific Absorption Rate (SAR)) increases.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of this invention is to provide an antenna device as well as a portable radio set which can sizably reduce deterioration of the communication.
The foregoing object and other objects of the invention have achieved by the provision of an antenna device of a diversity reception system comprising: a first antenna element installed so as to be retracted and pulled out freely, a fixed second antenna element, an unbalanced transmission line for supplying the first and the second antenna elements with power, balanced-to-unbalanced transformation means for implementing balanced-to-unbalanced transformation action between this unbalanced transmission line and the first and second antenna elements, switching means for selectively switching connections of the unbalanced transmission line with the first and the second antenna elements and with only the first antenna element so that at the time of reception, the first and second antenna elements are brought into connection with the unbalanced transmission line via the balanced-to-unbalanced transmission line, or only the second antenna element is brought into connection with the unbalanced transmission line, and the switching means are arranged to bring the unbalanced transmission line into connection with the first and the second antenna elements via the balanced-to-unbalanced transmission line so that the unbalanced transmission line supplies the first and the second antenna elements with power via the balanced-to-unbalanced transformation means so as to operate the above described first and second antenna elements as an antenna.
Consequently, at the time when the first and the second antenna elements are caused to operate as an antenna, the balanced-to-unbalanced transformation action of the balanced-to-unbalanced transformation means prevents the leakage current from flowing via the unbalanced transmission line from the first or the second antenna element to the ground member onto which this unbalanced transmission line is grounded, and prevents the above described ground member from operating as an antenna so that deterioration of antenna characteristics in the vicinity of the human body can be sizably reduced.
In addition, in the present invention, in a portable radio set having an antenna device of a diversity reception system, a first antenna element installed so as to be retracted and pulled out freely in the antenna device, a fixed second antenna element, an unbalanced transmission line to supply the first and the second antenna elements with power, balanced-to-unbalanced transformation means for implementing balanced-to-unbalanced transformation action between this unbalanced transmission line and the first and second antenna elements, switching means for selectively switching connections of the unbalanced transmission line with the first and the second antenna elements and with only the first antenna element so that at the time of reception, the first and second antenna elements are brought into connection with the unbalanced transmission line via the balanced-to-unbalanced transmission line, or only the second antenna element is brought into connection with the unbalanced transmission line are arranged to be installed, and the switching means are arranged to bring the unbalanced transmission line into connection with the first and the second antenna elements via the balanced-to-unbalanced transmission line so that the unbalanced transmission line supplies the first and the second antenna elements with power via the balanced-to-unbalanced transformation means so as to operate the above described first and second antenna elements as an antenna.
Consequently, at the time when the first and the second antenna elements are caused to operate as an antenna, the balanced-to-unbalanced transformation action of the balanced-to-unbalanced transformation means prevents the leakage current from flowing via the unbalanced transmission line from the first or the second antenna element to the ground member onto which this unbalanced transmission line is grounded, and prevents the above described ground member from operating as an antenna so that deterioration of antenna characteristics in the vicinity of the human body can be sizably reduced.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIGS. 1A and 1B
are block diagrams showing a circuit configuration of a conventional cellular telephone;
FIG. 2
is a block diagram showing a basic configuration of an antenna device of a diversity reception system;
FIGS. 3A and 3B
are block diagrams showing an inner configuration of a cellular telephone in which an antenna device of a diversity reception system is installed;
FIGS. 4A
to
4
C are schematic front views to be served to describe operation of a conventional shield case as an antenna;
FIG. 5
is a schematic wiring diagram showing a configuration of a balanced type antenna;
FIGS. 6A and 6B
are schematic graphs on voltage waves to be served to describe operation of the balanced type antenna;
FIG. 7
is a schematic view showing a configuration of an unbalanced type antenna;
FIGS. 8A and 8B
are schematic graphs on voltage waves to be served to describe operation of the unbalanced type antenna;
FIG. 9
is a schematic view showing a configuration of an antenna in medium excited figure;
FIGS. 10A and 10B
are schematic graphs on voltage waves to be served to describe an example of operation of the antenna in medium excited figure;
FIGS. 11A and 11B
are schematic sectional views to be served to describe a principle of a cellular telephone according to the present invention;
FIG. 12
is a schematic perspective view showing a configuration of an unbalanced transmission line configured by comprising a micro-strip line;
FIG. 13
is a schematic block diagram to be served to describe connections between an unbalanced transmission line and a rod antenna as well as a helical antenna;
FIG. 14
is a schematic block diagram to be served to describe connections between an unbalanced transmission line and a rod antenna as well as a helical antenna using a balun;
FIG. 15
is a block diagram showing a configuration of a balun;
FIG. 16
is a block diagram showing a configuration of a phasing circuit of the balun;
FIG. 17
is a block diagram to be served to describe connection between a helical antenna and an unbalanced transmission line at the time of reception;
FIGS. 18A and 18B
are schematic diagrams to be served to describe a shield case at the time of operation of an antenna;
FIG. 19
is a block diagram to be served to describe disposition of a matching circuit to the unbalanced side of a balun;
FIG. 20
is a block diagram to be served to describe disposition of a matching circuit to a balanced side of the balun;
FIGS. 21A and 21B
are block diagrams showing a configuration of the matching circuit disposed on the balanced side of the balun;
FIG. 22
is a schematic side view showing a first practical embodiment on a configuration of a cellular telephone according to the present invention;
FIG. 23
is a schematic diagram to be served to describe disposition of an antenna section, a first helical antenna, and a shield case;
FIGS. 24A and 24B
are block diagrams showing an inner configuration of a cellular telephone at the time of transmission and at the time of reception according to a first practical embodiment;
FIG. 25
is a block diagram showing an inner configuration of a cellular telephone at the time of reception according to the first practical embodiment;
FIGS. 26A and 26B
are block diagrams showing an inner configuration of a cellular telephone according to a second practical embodiment;
FIGS. 27A and 27B
are schematic sectional views showing a configuration of an antenna section;
FIGS. 28A and 28B
are block diagrams showing an inner configuration of a cellular telephone according to a third practical embodiment;
FIGS. 29A and 29B
are block diagrams showing an inner configuration of a cellular telephone according to a fourth practical embodiment;
FIG. 30
is a plan view showing a configuration of sheet line antenna;
FIGS. 31A and 31B
are block diagrams showing an inner configuration of a cellular telephone according to a fifth practical embodiment;
FIGS. 32A and 32B
are block diagrams showing an inner configuration of a cellular telephone according to a sixth practical embodiment;
FIGS. 33A and 33B
are schematic sectional views showing a configuration of a rod antenna;
FIGS. 34A and 34B
are block diagrams showing an inner configuration of a cellular telephone according to a seventh practical embodiment;
FIGS. 35A and 35B
are block diagrams showing an inner configuration of a cellular telephone according to an eighth practical embodiment;
FIGS. 36A and 36B
are schematic sectional views showing a configuration of an rod antenna;
FIGS. 37A and 37B
are block diagrams showing an inner configuration of a cellular telephone according to a ninth practical embodiment;
FIGS. 38A and 38B
are block diagrams showing an inner configuration of a cellular telephone according to a tenth practical embodiment;
FIGS. 39A and 39B
are schematic sectional views showing a configuration of a rod antenna;
FIG. 40
is a schematic view showing a configuration of an unbalanced transmission line made of a coaxial cable according to another practical embodiment;
FIGS. 41A
to
41
C are block diagrams showing a configuration of a phasing circuit according to another practical embodiment;
FIG. 42
is a schematic view showing a configuration of a balun according to another practical embodiment;
FIG. 43
is a schematic view showing a configuration of a balun according to another practical embodiment;
FIGS. 44A and 44B
are schematic views showing a configuration of a balun according to another practical embodiment;
FIG. 45
is a schematic view showing a configuration of a balun according to another practical embodiment;
FIG. 46
is a top view showing a coil to be used in a balun of trans form;
FIGS. 47A and 47B
are schematic sectional views and a schematic view showing a configuration of a Sperrtopf balun using a coaxial cable according to another practical embodiment;
FIG. 48
is a schematic view showing a configuration of the Ho Sperrtopf balun using a micro-strip line according to another practical embodiment;
FIG. 49
is a schematic view showing a configuration of a balun according to another practical embodiment;
FIGS. 50A and 50B
are schematic top views showing a configuration of an antenna element replacing first and second helical antennas according to another practical embodiment;
FIGS. 51A and 51B
are schematic top views showing a configuration of a film form antenna element according to another practical embodiment;
FIG. 52
is a schematic view showing a configuration of an antenna element replacing a rod antenna;
FIGS. 53A and 53B
are schematic sectional views showing a configuration of an antenna section according to another practical embodiment;
FIGS. 54A and 54B
are schematic sectional views showing a configuration of a rod antenna according to another practical embodiment;
FIGS. 55A and 55B
are schematic sectional views showing a configuration of the rod antenna according to another practical embodiment;
FIG. 56
is a schematic side view to be served to describe direction of retracting and pulling out an antenna section according to another practical embodiment;
FIG. 57
is a block diagram to be served to describe disposition of a matching circuit according to another practical embodiment;
FIG. 58
is a block diagram to be served to describe disposition of a matching circuit according to another practical embodiment;
FIG. 59
is a block diagram to be served to describe disposition of a first helical antenna according to another practical embodiment; and
FIG. 60
is a block diagram to be served to describe disposition of a sheet line antenna according to another practical embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENT
Preferred embodiments of this invention will be described with reference to the accompanying drawings.
(1) Principle
As shown in
FIG. 5
, an antenna, which is configured by comprising a first and a second antenna elements
30
and
31
which are structurally as well as electrically symmetrical like an dipole antenna, is brought into operation with a voltage having the same amplitude but having the phases shifted by around 180 degrees for these first and second antenna elements
30
and
31
as shown in
FIGS. 6A and 6B
to take an excited figure of balanced type so as to be categorized as an antenna of balanced type.
In addition, as shown in
FIG. 7
, the one, which is configured by comprising a ground member
32
which can be regarded to structurally have an asymmetric and infinite size as in a monopole antenna disposed approximately perpendicularly on the ground member which is more vast than a disk having a radius of, for example, one wave length (electrical length) and can be regarded to have an infinite size and an antenna
33
disposed approximately perpendicular thereto, makes as shown in
FIGS. 8A and 8B
this vast ground member
32
approximately zero-potential, and a voltage varying in a predetermined cycle is given rise to in the antenna
33
, which then operates to take an unbalanced excited figure, and thus is categorized as an antenna of unbalanced type.
Incidentally, in such an antenna of unbalanced type, which has the vast ground member
32
, the image current flowing in this antenna of unbalanced type can be assumed without difficulty, and thus the antenna characteristics of the above described antenna of unbalanced type can be selected approximately as equal as in the antenna of balanced type.
Moreover, as shown in
FIG. 9
, as this kind of antenna, there is also an antenna being configured by comprising the structurally and electrically asymmetric first and second antenna elements
34
and
35
such as a rod antenna
4
(in
FIGS. 1A and 1B
as well as
FIGS. 3A and 3B
) shown in a conventional cellular telephones
1
and
25
(in
FIGS. 1A and 1B
FIGS.
3
A and
3
B), a helical antenna
5
(in
FIGS. 1A and 1B
as well as
FIGS. 3A and 3B
) or a built-in antenna
23
(in
FIGS. 3A and 3B
) and a shield case
27
(in
FIGS. 4A
to
4
C).
The antenna in such a configuration is structurally and electrically asymmetric, and therefore, as shown in
FIGS. 10A and 10B
for example, takes a medium excited figure which can be regarded neither as an excited figure of balanced type nor as an excited figure of unbalanced type, and therefore is categorized as an antenna which is different from the antenna of balanced type and the antenna of unbalanced type (and hereinafter this will be called as antenna of medium excited figure).
In addition,
FIG. 11
is to show a cellular telephone
36
in accordance with the present invention with the matching circuit having been removed, and this cellular telephone
36
is provided with an antenna device
40
of the diversity reception system having the rod antenna
38
as well as the helical antenna
39
for example as the first and second antenna elements in the housing
37
.
This rod antenna
38
as well as the helical antenna
39
is structurally asymmetric, but will become electrically symmetric with the approximately equal electrical length being selected so as to configure an antenna taking an excited figure of approximately balanced type (hereafter to be referred to as antenna of approximately balanced type).
Incidentally, in the present invention, unless specified otherwise in particular, the antenna provided in the antenna device will be structurally asymmetrical but will become electrically symmetrical, and will take an excited feature of balanced type so as to be categorized as the antenna of approximately balanced type.
In addition, as shown in
FIG. 11A
, in the antenna device
40
, both the rod antenna
38
and the helical antenna
39
will be used as an antenna element for transmission at the time of transmission.
In addition, in the antenna device
40
, the rod antenna
38
as well as the helical antenna
39
is used for an antenna element for reception at the time of reception as shown in
FIG. 11A
, and as shown in
FIG. 11B
only the helical antenna
39
is used for the antenna element for reception while this rod antenna
38
as well as well as the helical antenna
39
and a single helical antenna
39
are selectively used for receiving reception signals at high levels so as to reduce multi-path phasing.
Incidentally, the antenna device
40
is provided with an unbalanced transmission line
42
being configured by a micro-strip line, and both the rod antenna
38
and the helical antenna
39
are brought into electrical connection or only the helical antenna
39
is brought into electrical connection with the transmission-reception circuit
41
via this unbalanced transmission line
42
.
Here,
FIG. 12
shows a micro-strip line having been applied as an unbalanced transmission line
42
, which is configured by comprising a strip conductor
44
being provided as a hot side on one surface
43
A of the dielectric layer
43
having a predetermined thickness and an earth conductor
45
being provided as a ground side on the other surface
43
B of the dielectric layer
43
, and is formed on a circuit substrate (not shown) housed inside the housing
37
for example.
And in such an antenna device
40
, as shown in
FIG. 13
, when both the rod antenna
38
and the helical antenna
39
are used together at the time of transmission and at the time of reception, basically for example the rod antenna
38
is brought into electrical connection with the transmission-reception circuit
41
via the hot-side
44
of the unbalanced transmission line
42
, and the helical antenna
39
is brought into electrical connection with the transmission-reception circuit
41
via the ground side
45
of this unbalanced transmission line
42
.
However, since in this antenna device
40
the rod antenna
38
and the helical antenna
39
take an excited figure of approximately balanced type while the unbalanced transmission line
42
takes an unbalanced excited figure due to grounding of the ground side
45
and thus they take excited figures being different each other, and the rod antenna
38
as well as the helical antenna
39
and the unbalanced transmission line
42
are brought into direct electrical connection so that the difference in an excited figure results in unbalanced current when this rod antenna
38
as well as the helical antenna
39
operates as an antenna for dual use of transmission and reception.
As a result hereof, in the cellular telephone
36
, a leakage current i
2
flows from the helical antenna
39
to the shield case, which is approximately equally potential with this via the ground side
45
of the unbalanced transmission line
42
and, thus this leakage current i
2
operates the shield case as an antenna so that when the housing
37
approaches the hand or the head of a user, the antenna characteristics are deteriorated.
Thus, as shown in
FIG. 14
, in the antenna device
40
according to the present invention, a balun (balanced-to-unbalanced transformer)
46
is provided to implement balanced-to-unbalanced transformation among the unbalanced transmission line
42
, the rod antenna
38
, and the helical antenna
39
.
This balun
46
, for example as shown in
FIG. 15
, is configured by the first and second transmission lines
47
and
48
of two systems to be provided, together with the phasing device
49
to be provided midway in this second transmission line
48
.
In addition, in the balun
46
, in the connecting side of the unbalanced transmission line
42
(this hereinafter to be referred to as unbalanced side), one ends of the first as well as second transmission lines
47
and
48
are respectively brought into electrical connection with the hot side
44
of this unbalanced transmission line
42
, and at the connection side of the antenna element (this hereinafter to be referred to as balanced side), the other ends of these first as well as second transmission lines
47
and
48
are respectively brought into electrical connection with the rod antenna
38
and the helical antenna
39
.
Here, the phasing device
49
, for example as shown in
FIG. 16
, is configured by symmetrically-structured T-type phasing circuits
50
being assembled wherein two dielectric reactance elements L
1
and L
2
are brought into connection in series and have their middle connection point P
1
coming into conductive connection with one end of a capacitive reactance element C
1
together with the other end of the above described capacitive reactance element C
1
being grounded.
In addition, in the balun
46
, a high-frequency signal supplied by the transmission-reception circuit
41
via the hot side
44
of the unbalanced transmission line
42
is taken in from the unbalanced side so that this high-frequency signal without any change is sent out into the rod antenna
38
at the balanced side via the first transmission line
47
, and at the same time in the phasing device
49
of the second transmission line
48
as the other side, this high-frequency signal undergoes phase shifting by around 180 degrees against the rod antenna
38
within the working frequency band, and the obtained high-frequency signal with shifted phase is sent out to the helical antenna
39
at the balanced side.
Thereby, the balun
46
can operate the rod antenna
38
and the helical antenna
39
as an electrically symmetrical antenna of approximately balanced type that gives rise to a voltage figure as in the above described
FIGS. 6A and 6B
as balanced-to-unbalanced transformation action.
Thus, this balun
46
prevents the rod antenna
38
and the helical antenna
39
from giving rise to an unbalanced state in current so as to prevent the leakage current i
2
from flowing from the helical antenna
39
to the ground side
45
of the unbalanced transmission line
42
and as a result hereof can prevents the shield case from operating as an antenna.
Incidentally, such a balun
46
can be extensively miniaturized for forming in its entirety, and thus can be easily installed in the cellular telephone
36
which tends to be miniaturized and light-weighed since, as the inductive reactance elements L
1
and L
2
and the capacitive reactance element C of the above described phasing circuit
50
for the phasing device
49
, those, for example, in micro chip shape of around 1 mm cube can be used.
In addition, in the antenna device
40
, as shown in
FIG. 17
, when only the helical antenna
39
is used at the time of reception, this helical antenna
39
is brought into electrical connection with the transmission-reception circuit
41
via the hot side
44
of the unbalanced transmission line
42
without using any balun in particular, and the ground side
45
of the unbalanced transmission line
42
, that is not brought into connection with any antenna element, is brought into electrical connection with the transmission circuit
41
.
Thus, in the antenna device
40
, when this helical antenna
39
is supplied with power from the transmission-reception circuit
41
via the unbalanced transmission line
42
, the above described helical antenna
39
is brought into operation as an antenna, but at that time the leakage current i
2
flows into the shield case
51
from the ground side
45
of the unbalanced transmission line
42
so that this shield case operates as an antenna.
Accordingly, in the cellular telephone
36
according to the present invention, as shown in
FIGS. 18A and 18B
, when only the helical antenna
39
is used at the time of reception, the shield case
51
operates as an antenna, and therefore when the housing
37
is grabbed by the hand of a user or the housing
37
approaches the head of a user, similarly to the conventional cellular telephone, the antenna characteristics of this cellular telephone
36
in the vicinity of a human body is deteriorated.
However, in this cellular telephone
36
, when both the rod antenna
38
and the helical antenna
39
are used together at the time of transmission and at the time of reception, thus two antenna elements are used so that not only the antenna characteristics can be improved but also deterioration of the antenna characteristics of this cellular telephone
36
in the vicinity of a human body is sizably reduced due to the shield case
51
being made not to operate as an antenna even if the housing
37
is grabbed by the hand of a user or the housing
37
approaches the head of a user, and the deterioration in communication quality can be sizably reduced.
In addition, in the cellular telephone
36
, when both the rod antenna
38
and the helical antenna
39
are used together at the time of transmission and reception, the shield case
51
is caused to function only as an essential ground as well as electrical shield plate, and not to operate as an antenna so that the power to be absorbed by a human body from this shield case
51
is controlled to sizably reduce SAR. In addition thereto, when only the helical antenna
39
operates as an antenna, the shield case
51
also operates as an antenna, however, there is no problem about the power i.e. SAR to be absorbed by a human body from this shield case
51
.
Incidentally,
FIGS. 11A and 11B
show the transmission-reception circuit
41
that is disposed outside the shield case
51
inside the housing
37
in order to simplify description, but actually this transmission-reception circuit
41
is disposed inside the shield case
51
. In addition, the balun
46
is disposed outside the shield case
51
for description, but this balun
46
can be disposed either inside or outside the shield case
51
.
In addition, in
FIGS. 11A and 11B
,
FIGS. 13
to
15
, and
FIG. 17
, the matching circuit is removed from the drawing in order to simplify description, but as shown in
FIG. 19
, the matching circuit
52
can be provided for example between the unbalanced transmission line
42
and the balun
46
.
Moreover, as shown in
FIG. 20
, the matching circuit
53
can be provided between the balun
46
and the rod antenna
38
as well as the helical antenna
39
. However, when the matching circuit
53
is grounded at this time, even if the balun
46
implements the balanced-to-unbalanced transforming function, the leakage current given rise to in the helical antenna
39
flows into the shield case
51
via this matching circuit
53
, and as a result hereof, this shield case
51
will operate as an antenna.
Accordingly, as shown in
FIGS. 21A and 21B
, if such a matching circuit
53
is arranged to be configured by comprising an inductive reactance element L
3
or a capacitive reactance element C
2
that is brought into connection in parallel between the two transmission lines
54
and
55
to bring the balanced side of the balun
46
and the rod antenna
38
as well as the helical antenna
39
into electrical connection so as not to be grounded, this matching circuit
53
can be provided between the balun
46
and the rod antenna
38
as well as the helical antenna
39
without any problems.
(2) First Practical Embodiment
In
FIG. 22
, the numeral
60
denotes a cellular telephone in its entirety according to a first practical embodiment, being configured by comprising an antenna device
62
of a diversity reception system being provided in a housing
61
made of non-conductive member such as synthetic resin, etc.
This housing
61
is formed like a box where a speaker
63
, a liquid crystal display section
64
, various operation keys
65
and a microphone
66
are disposed in the front surface
61
A.
In addition, in the antenna device
62
, an antenna section
67
having a first antenna element is installed in the side of the back surface
61
C of the upper surface
61
B of the housing
61
which can be retracted and pulled out freely approximately in parallel in the elongated direction of this housing
61
(this hereinafter to be referred to as the box elongated direction) and as a second antenna element the first antenna element
68
of a fixed type formed by conductive line member being spirally rolled is disposed inside the upper portion of the back surface
61
C of the housing
61
.
In addition, in this cellular telephone
60
, the first antenna element of the antenna section
67
and the first helical antenna
68
are assembled and disposed in side of the back surface
61
C of the housing
61
so that, even if the front surface
61
A of this housing
61
approaches the head of a user for telephone communication, the first antenna element as well as the first helical antenna
68
can be disposed remote from the head of the user, and thus deterioration of antenna characteristics of this cellular telephone in the vicinity of a human body is arranged to be reduced.
In addition, in the cellular telephone
60
, as shown in
FIG. 23
, the antenna section
67
as well as the first helical antenna
68
is disposed so as to be electrically separated from the shield case
69
housed inside the housing
61
, and thereby, in the case where the first antenna element as well as the first helical antenna
67
, which is used as an antenna element for dual use of transmission and reception, is brought into capacitive junction with the shield case
69
80
that the above described shield case
69
is arranged to be prevented from operating as an antenna.
Actually,
FIGS. 24A and 24B
and
FIG. 25A
are to show the inner configuration of this cellular telephone
60
without the matching circuit and the shield case, and inside the housing
61
, a circuit substrate (not shown) on which various circuit elements such as the transmission-reception circuit
41
and the balun
46
, etc. are housed and a shield case made of conductive member covering this circuit substrate is housed.
In addition, in the antenna device
62
, the rod antenna
70
made of a stick form conductive line member as the first antenna element and the second helical antenna
71
formed with a conductive line member spirally scrolled are installed in the antenna section
67
.
The lower end of this rod antenna
70
and the power supply member for the rod
72
made of a conductive member having T-shaped sectional view are brought into electrical as well as mechanical connection, and the upper end of this rod antenna
70
and the connecting section
73
made of non-conductive member are brought into mechanical connection.
In addition, the lower end of the second helical antenna
71
and the power supply member for the helical
74
made of conductive member are brought into electrical as well as mechanical connection, and this power supply member for the helical
74
and the connecting section
73
are brought into mechanical connection. Thereby, the second helical antenna
71
and the rod antenna
70
are mechanically linked with the connecting section
73
but electrically separated.
In addition, the rod antenna
70
is covered with the antenna cover for the rod
75
made of non-conductive member and the second helical antenna
71
is housed in the antenna cover for the helical
76
which is made of non-conductive member and formed in a shape of a cap so that they will not be brought into direct contact with a human body.
In addition thereto, in this antenna section
67
, an antenna power supply terminal
77
made of conductive member and formed to shape a ring for example is disposed inside the upper surface
61
B of the housing
61
and the rod antenna
70
is inserted through it. In addition, this antenna power supply terminal
77
and the balanced side of the balun
46
are brought into electrical connection.
Thereby, in the antenna device
62
, at the time when the antenna section
67
is retracted, this antenna section
67
is pushed toward the retracting direction and the antenna cover for the helical
76
is thrust onto the upper surface
61
B of the housing
61
to bring the power supply member for the helical
74
into electrical connection with the antenna power supply terminal
77
, and thus to bring the balanced side of the balun
46
and the second helical antenna
71
into electrical connection sequentially via the antenna power supply terminal
77
and the power supply member for the helical
74
and to electrically separate the rod antenna
70
from the balanced side of this balun
46
.
In addition, in the antenna device
62
, at the time when the antenna section
67
is pulled out, this antenna section
67
is pulled toward the pulling direction and the protrusion
72
A of the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
to bring this power supply member for the rod
72
into electrical connection with the antenna power supply terminal
77
, and thereby to bring the balanced side of the balun
46
and the rod antenna
70
into electrical connection sequentially via the antenna power supply terminal
77
and the power supply member for the rod
72
and to electrically separate the second helical antenna
71
from the balanced side of this balun
46
.
Incidentally, at this time, the power supply member for the rod
72
is brought into electrical connection with the antenna power supply terminal
77
, and in addition, performs its role as a stopper to prevent the antenna section
67
from being pulled out outside the housing
61
.
Thus, in the antenna device
62
, the electrical connection between the rod antenna
70
toward the balanced side of the balun
46
and the second helical antenna
71
is switched in accordance with retracting and pulling out of the antenna section
67
so that either this rod antenna
70
or the second helical antenna
71
is arranged to be used as an antenna element.
In addition thereto, the antenna device
62
is provided with an unbalanced transmission line
42
comprising the micro-strip line formed in the circuit substrate inside the housing
61
and the first as well as second switching device
78
and
79
formed in the above described circuit substrate.
This first switch
78
has two points of contact to implement switching electrically, and one point of contact is brought into electrical connection with the balanced side of the balun
46
, and the other point of contact is brought into electrical connection with the one end of the first helical antenna
68
.
In addition, the second switch
79
has three points of contact that can be electrically switched, in such a way that the two points of contact divide the hot side of the unbalanced transmission line
42
into two, and these two points of contact are brought into electrical connection with the transmission-reception circuit
41
or the unbalanced side of the balun
46
via the hot side which is divided into two respectively to be applied to these two points of contact, and the remaining one point of contact is brought into electrical connection with the other end of the first helical antenna
68
.
In addition, in the antenna device
62
, the first and second switches
78
and
79
at the time of transmission undergo switching control to connect the first helical antenna
68
electrically with the balanced side of the balun
46
via the first switch
78
, and in addition to connect the transmission-reception circuit
41
electrically with the unbalanced side of this balun
46
and the second switch
79
via the unbalanced transmission line
42
and the second switching device
79
.
Thereby, in the antenna device
62
, the rod antenna
70
or the second helical antenna
71
, which is brought into electrical connection with the transmission-reception circuit
41
sequentially via the unbalanced transmission line
42
and the balun
46
, and the first helical antenna
68
are to be used as an antenna element for transmission.
In addition, in the antenna device
62
, the first and second switches
78
and
79
at the time of reception undergo switching control to connect the first helical antenna
68
electrically with the balanced side of the balun
46
via the first switch
78
, and in addition to connect the transmission-reception circuit
41
electrically with the unbalanced side of this balun
46
via the unbalanced transmission line
42
and the second switch
79
, or as shown in
FIG. 25
one end of the first helical antenna
68
is opened via the first switch
78
, and the other end of this first helical antenna
68
is brought into electrical connection with the transmission-reception circuit
41
via the second switch
79
and the unbalanced transmission line
42
.
Thereby, in the antenna device
62
, the rod antenna
70
or the second helical antenna
71
, which is brought into electrical connection with the transmission-reception circuit
41
sequentially via the unbalanced transmission line
42
and the balun
46
, and the first helical antenna
68
are to be used as an antenna element for reception, or this antenna element for reception is to be selectively switched and used so that only the first helical antenna
68
, which is brought into electrical connection with the transmission-reception circuit
41
via the unbalanced transmission line
42
, is treated as the antenna for reception.
Thus, in this antenna device
62
, the antenna element for reception to thus selectively implement switching for use is to execute the diversity reception selectively receiving the reception signals of high levels.
Actually, in the antenna device
62
, at the time of transmission as well as reception, when the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
are used together, the transmission-reception circuit
41
supplies power to the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
sequentially via the unbalanced transmission line
42
and the balun
46
so as to cause the both antenna elements of this rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
to give rise to a voltage figure as in the above described
FIGS. 6A and 6B
and to operate as an antenna of approximately balanced type.
In addition, in the antenna device
62
, at this time, function of the balun
46
with respect to balancing and unbalancing prevents the leakage current from flowing from the rod antenna
70
or the second helical antenna
71
to the ground side of the unbalanced transmission line
42
.
Thereby, in the antenna device
62
, the leakage current flows from the ground side of the unbalanced transmission line
42
to the shield case to prevent this shield case from operating as an antenna so that the above described shield case can function solely as essential electrical shield plate and ground.
Thus, in this cellular telephone
62
, deterioration of the antenna characteristics of this cellular telephone
60
in the vicinity of a human body can be sizably reduced in consideration of the portion due to the shield case being thus made not to operate as an antenna even if the housing
61
is grabbed by the hand of a user and the housing
61
approaches the head of a user, and the power to be absorbed by a human body from this shield case can be controlled.
Incidentally, in the antenna device
62
, when only the first helical antenna
68
is used at the time of reception, the transmission-reception circuit
41
supplies the first helical antenna
68
with power via the unbalanced transmission line
42
so as to operate this first helical antenna
68
as an antenna.
Thus, the cellular telephone
60
operates by repeating in a time-shared fashion the transmission processing mode to actually transmit and process transmission signals, the comparison processing mode to compare and process the levels of reception signals, and the reception processing mode to receive and process the reception signals, and at the time of the transmission processing mode, the transmission-reception circuit
41
supplies the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
with the transmission signals made of high frequency signals sequentially via the unbalanced transmission line
42
and the balun
46
, and thereby transmits these transmission signals to the base station (not shown) via the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
.
In addition, the cellular telephone
60
, at the time of the comparison processing mode, switches and controls the first and second switches
78
and
79
rapidly, and brings the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
into electrical connection sequentially with the transmission-reception circuit
41
via the unbalanced transmission line
42
and the balun
46
so as to supply with the reception signals made of high frequency signals, which are transmitted from the base station and received via this rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
, to the transmission-reception circuit
41
sequentially via the balun
46
as well as the unbalanced transmission line
42
, and at the same time, with the transmission-reception circuit
41
being brought into electrical connection with only this second helical antenna
68
via the unbalanced transmission line
42
, to supply the reception signals, which are transmitted from the base station and received via this first helical antenna
68
, to the transmission-reception circuit
41
sequentially via the balun
46
as well as the unbalanced transmission line
42
.
Thereby, the cellular telephone
60
compares the level of the reception signals received by this rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
with the level of the reception signals received only by the first helical antenna
68
, and selects the antenna element that has received the reception signals of higher level.
In addition, the cellular telephone
60
selects the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
as the antenna which has received the reception signals of the higher level with this comparison processing mode, and then switches and controls the first and second switches
78
and
79
in the subsequent reception processing mode, and brings the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
into electrical connection with the transmission-reception circuit
41
sequentially via the balun
46
and the unbalanced transmission line
42
so as to supply the transmission-reception circuit
41
with the reception signals which have been transmitted from the base station and received via this rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
.
On the other hand, the cellular telephone
60
selects only the first helical antenna
68
as the antenna which has received the reception signals of the higher level with this comparison processing mode, and then switches and controls the first and second switch device
78
and
79
in the subsequent reception processing mode, and brings only this second helical antenna
68
into electrical connection with the transmission-reception circuit
41
via the unbalanced transmission line
42
so as to supply the transmission-reception circuit
41
with the reception signals which have been transmitted from the base station and received via this first helical antenna
68
.
Thereby, this cellular telephone
60
, at the time of the reception mode, selectively switches for use the antenna element for reception in accordance the level of the reception signals with the diversity reception system so as to be able to selectively receive the reception signals of high levels all time and reduce multi-path phasing.
In addition, the cellular telephone
60
uses the first helical antenna
68
as the antenna element in accordance with the levels of the reception signals at the time of the reception mode, and then, as described above the shield case operates as an antenna so that the antenna characteristics in the vicinity of a human body are deteriorated similarly to the conventional cellular telephone, and at the time when both of the rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
are used as an antenna element for reception in accordance with the levels of reception signals at the time of this reception mode and at the time when both of this rod antenna
70
or the second helical antenna
71
and the first helical antenna
68
are used as an antenna element for transmission at the time of this transmission mode, the balanced-to-unbalanced transforming function of the balun
46
can prevent the shield case from operating as an antenna, and thus deterioration of the antenna characteristics in the vicinity of a human body can be sizably reduced.
Incidentally, this cellular telephone
60
, in which the antenna section
67
is provided so as to be able to be retracted and pulled out freely, is used with this antenna section
67
pulled out at the time of communication, but when it is being carried, will come into the waiting state with the antenna section
67
to be pushed into the housing
61
in order that it is possible to prevent its portability from being hampered.
Incidentally, in the case of this first practical embodiment, in the antenna device
62
, the rod antenna
70
is disposed with its elongated direction approximately in parallel along the elongated direction of the box, and the first helical antenna
68
is disposed with the central axis of its spiral (this hereinafter to be referred to as the first central axis) approximately perpendicular to the box elongated direction, and the second helical antenna
71
is disposed with the central axis of its spiral (this hereinafter to be referred to as the second central axis) approximately in parallel to the box elongated direction.
Accordingly, in this antenna device
62
, the rod antenna
70
as Well as the second helical antenna
71
can improve the level of polarization on a surface approximately in parallel along the box elongated direction, and the first helical antenna
68
is made to have its first central axis approximately perpendicular to the box elongated direction so that the level of polarization on the surface approximately in parallel along the direction approximately perpendicular to this box elongated direction can be improved.
In addition thereto, in the antenna device
62
, thus the level of polarization on the surface approximately in parallel along the box elongated direction and the direction perpendicular to the box elongated direction can be improved so that according thereto the level of polarization on the surface approximately in parallel along the predetermined direction between this box elongated direction and the direction perpendicular to the box can also be improved.
Accordingly, the cellular telephone
60
can implement transmission and reception to and from the base station comparatively stably even if the figure of this cellular telephone
60
changes.
(3) Second Practical Embodiment
FIGS. 26A and 26B
, in which the same numerals as in
FIGS. 24A and 24B
are given to show the corresponding portions, show a cellular telephone
80
according to the second practical embodiment, which is configured as in the cellular telephone
60
(
FIGS. 24A and 24B
) according to the above described first practical embodiment except the configuration of the antenna section
82
of the antenna device
81
.
In
FIGS. 27A and 27B
in which the same numerals denotes the corresponding portions in
FIGS. 24A and 24B
, this antenna section
81
comprises a first antenna half part
83
and a second antenna half part
85
, the first antenna half part
83
made of conductive cylindrical member with its lower end with which the power supplying member for the rod
72
is brought into electrical and mechanical connection and with its upper end where the stopper for pull-out
84
is provided, and the second antenna half part
85
made of conductive stick form member being inserted through the cavity of this first antenna half part
83
in such a fashion so as to be able to be retracted and pulled out freely.
In addition, the lower end of the second antenna half part
85
located inside the cavity of the first antenna half part
83
is brought into electrical and mechanical connection with a sliding spring
86
made of conductive member and the upper end of the second antenna half part
85
is brought into mechanical connection with the connection portion
87
made of non-conductive member.
In addition, this connection portion
87
is brought into mechanical connection with a power supply member for a helical
74
, and thereby the second antenna half part
85
and the second helical antenna
71
are brought into mechanical connection with this connection portion
87
, and nevertheless are electrically separated.
Moreover, these first and second antenna half parts
83
and
85
are respectively covered by antenna covers
88
and
89
.
Thereby the antenna section
82
forms an elastic rod antenna with the sliding sprint
86
sliding inside the cavity of this first antenna half part
83
when the second antenna half part
85
is thrust into, or pulled out of, the first antenna half part
83
so that the first antenna half part
83
and the second antenna half part
85
are brought into electrical connection via this sliding spring
86
.
Actually, this antenna device
81
(
FIGS. 26A and 26B
) will thrust the second antenna half side
85
into the first antenna half side
83
so as to thrust this antenna part
82
throughout inside the housing
61
when the antenna cover for the helical
76
is pushed in the retracting direction at the time of when the antenna section
82
is retracted.
In addition, in the antenna device
81
, the antenna cover for the helical
76
is thrust onto the upper surface
61
B of the housing
61
, and then the second antenna half side
85
in its entirety is thrust into the first antenna half part
83
so that the shortened rod antenna is formed by this first and second antenna half parts
83
and
85
, and under this state, the antenna section
82
is retracted inside the housing
61
for housing.
Incidentally, in the antenna device
81
, at this time, the power supply member for the helical
74
is brought into electrical connection with the antenna power supply terminal
77
so that the second helical antenna
71
is brought into electrical connection with the balanced side of the balun
46
.
In addition, in the antenna device
81
, when the antenna section
82
is pulled out, the antenna cover for the helical
76
is pulled in the pulling direction so that the antenna section
82
is pulled out outside from the upper surface
61
B of the housing
61
while the second antenna half part
85
is pulled out from the first antenna half section
83
.
In addition, in the antenna device
81
, when the protrusion
72
A of the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, the second antenna half part
85
is fully pulled out from the first antenna half part
83
and thus the rod antenna, which is extended by these first and second antenna half parts
83
and
85
, is formed, and this extended rod antenna is to be pulled outside the housing
61
.
Thereby, in the cellular telephone
80
, when the antenna section
82
is thrust, the above described antenna section
82
is shortened to form the rod antenna, which is thrust into inside the housing
61
, so that the portion of this antenna section
82
thrust into inside the housing
61
can be remarkably made short compared with the cellular telephone
60
(
FIGS. 24A and 24B
) according to the above described first practical embodiment.
Accordingly, in the cellular telephone
80
, also in the case where the antenna section
82
can not be thrust easily due to the space occupied by a battery, etc. inside the housing
61
, this antenna section
82
can be easily installed on the upper surface
61
B of the housing
61
in a fashion so as to be freely retracted and pulled out.
(4) Third Practical Embodiment
FIGS. 28A and 28B
, in which the same numerals as in
FIGS. 24A and 24B
are given to show the corresponding portions, show a cellular telephone
90
according to the third practical embodiment, which is configured as in the cellular telephone
60
(
FIGS. 24A and 24B
) according to the above described first practical embodiment except the disposing location as well as the posture of the first helical antenna
68
of the antenna device
91
.
The first helical antenna
68
is disposed to have the first central axis being made approximately in parallel along the box elongated direction and approximately overlapping the extended line of the first central axis of the second helical antenna
71
.
In addition, in the antenna device
91
, when the antenna section
67
is thrust and pulled out, the rod antenna
70
is arranged so as to be able to be retracted and pulled out so that it is inserted through this first helical antenna
68
along the first central axis.
Thus, in the antenna device
91
, the first helical antenna
68
and the antenna section
67
are disposed together so that the disposition space for the first helical antenna
68
and the antenna section
67
can be made remarkably small.
Thereby, in the cellular telephone
90
, the housing
61
can be made remarkably small compared with the above described first practical embodiment, and thus this cellular telephone
90
can be miniaturized.
(5) Fourth Practical Embodiment
FIGS. 29A and 29B
, in which the same numerals as in
FIGS. 24A and 24B
are given to show the corresponding portions, show a cellular telephone
92
according to the fourth practical embodiment, which is configured as in the cellular telephone
60
(FIGS.
24
A and
24
B) according to the above described first practical embodiment except the configuration of the antenna device
93
.
This antenna device
93
is provided with an antenna element forming a line with conductive sheet (this hereinafter to be referred to sheet line antenna)
94
as shown in
FIG. 30
instead of the first helical antenna
68
(
FIGS. 24A and 24B
) of the cellular telephone
60
according to the above described first practical embodiment.
This sheet line antenna
94
, which is selected to have approximately the same electrical length as the electrical length of the rod antenna
70
or the second helical antenna
71
, is stuck onto the inner side of the upper surface
61
B of the housing
61
.
Thereby, in the cellular telephone
92
, this sheet line antenna
94
is remarkably thin compared with the first helical antenna
68
and is disposed inside the upper surface
61
B of the housing
61
so that, when a hand of a user grabbing the housing
61
and this housing
61
approach the head of the user, this sheet line antenna
94
can be made to keep away from a human body, and thus deterioration of antenna characteristics of this cellular telephone
92
in the vicinity of the human body can be reduced further.
In addition, in this cellular telephone
92
, this sheet line antenna
94
can be disposed in a remarkably small space compared with the disposition space for the first helical antenna
68
inside the housing
61
, and thus the housing
61
can be miniaturized along the box elongated direction.
(6) Fifth Practical Embodiment
FIGS. 31A and 31B
, in which the same numerals as in
FIGS. 24A and 24B
are given to show the corresponding portions, show a cellular telephone
95
according to the fifth practical embodiment, which is configured as in the cellular telephone
60
(
FIGS. 24A and 24B
) according to the above described first practical embodiment except the configuration of the antenna device
96
.
This antenna device
96
has a cap-shaped antenna cover for the helical
97
, which is provided in the back surface
61
C side of the upper surface
61
B of the housing
61
, and this antenna cover for the helical
97
has an upper surface
97
A, in which a rod antenna
70
is provided along the box elongated direction in a fashion so as to be able to be retracted and pulled out freely.
The lower end of this rod antenna
70
is brought into electrical and mechanical connection with the power supply member for the rod
72
, and the upper end of the above described rod antenna
70
is brought into mechanical connection with an antenna knob
98
having T form sectional view made of non-conductive member.
In addition, inside the antenna cover for the helical
97
has the second helical antenna
71
for fixing, the second central axis of which is disposed approximately in parallel along the elongated direction of the rod antenna
70
, and the lower end of this second helical antenna
70
is brought into electrical and mechanical connection with the antenna power supply terminal
77
.
In addition, in the antenna device
96
, the rod antenna
70
is arranged to be inserted into the second helical antenna
71
and the antenna power supply terminal
77
along the second central axis so as to be thrust and pulled out.
Actually, in this antenna device
96
, at the time when the rod antenna
70
is retracted, the antenna knob
98
is pushed in the direction of retracting so as to be thrust onto the upper surface
97
A of the antenna cover for the helical
97
, and then, this antenna knob
98
is thrust over the second helical antenna
71
and the antenna power supply terminal
77
, and thus the rod antenna
70
is electrically separated from the antenna power supply terminal
77
and housed inside the housing
61
.
In addition, in the antenna device
96
, under this state at the time of transmission and at the time of reception, the transmission-reception circuit
41
, which supplies this first and second helical antenna
68
and
71
with power sequentially via the unbalanced transmission line
42
and the balun
46
, operates these first and second helical antenna
68
and
71
as an antenna of approximately balanced type, and at this time balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the second helical antenna
71
to the ground side of the unbalanced transmission line
42
.
In addition, in the antenna device
96
, at the time when the rod antenna
70
is pulled out, the antenna knob
98
is pulled in the direction of drawing so that the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, then the rod antenna
70
is pulled out outside from the upper surface
97
A of the antenna cover for the helical
97
, and the lower end of this rod antenna
70
is brought into electrical connection with the lower end of second helical antenna
71
via the power supply member of the rod
72
and the antenna power supply terminal
77
so that a compound antenna is formed from the above-described rod antenna
70
and the second helical antenna
71
.
In addition, in this-antenna device
96
, under this state, at the time of transmission and at the time of power supply, the transmission-reception circuit
41
provides these first helical antenna
68
and the compound antenna with power sequentially via the unbalanced transmission line
42
and the balun
46
so as to operate the above described first helical antenna
68
and the compound antenna as an antenna of approximately balanced type and at that time, balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the compound antenna to the ground side of the unbalanced transmission line
42
.
Accordingly, in this cellular telephone
95
, at the time of transmission and at the time of reception, in the case where the second helical antenna
71
or the compound antenna is used together with the first helical antenna
63
, as in the above described first practical embodiment, the leakage current is prevented from flowing from the ground side of the unbalanced transmission line
42
to the shield case so as not to operate this shield case as an antenna, and thus causes the shield case to function only as an essential electrical shield plate and the ground.
Thereby, in this cellular telephone
95
, due to the portion of the shield case not to operate as an antenna, even if the housing
61
is grabbed by a hand of a user and the housing
61
approaches the head of a user so that this shield case is disposed in the vicinity of a human body, deterioration of the antenna characteristics of the cellular telephone
95
in the vicinity of the human body can be sizably reduced, and the power absorbed by the human body from the shield case i s controlled to sizably reduce the SAR.
Incidentally, in this cellular telephone
95
, even in the case where the second helical antenna
71
can hardly be disposed inside the housing
61
due to the space occupied by a battery, etc, this second helical antenna
71
can be installed easily.
(7) Sixth Practical Embodiment
FIGS. 32A and 32B
, in which the same numerals as in
FIGS. 31A and 31B
are given to show the corresponding portions, show a cellular telephone
100
according to a sixth practical embodiment, which is configured as in the cellular telephone
95
(FIGS.
31
A and
31
B) according to the above described fifth practical embodiment except the configuration of the antenna device
101
.
In
FIGS. 33A and 33B
, in which the same numerals as in
FIGS. 31A and 31B
as well as
FIGS. 27A and 27B
are given to show the corresponding portions, the antenna device
101
has an elastic rod antenna
102
in which the second antenna half part
85
is inserted into the first antenna half part
83
in a fashion so as to be retracted and pulled out freely, and the upper end of this second antenna half part
85
is brought into mechanical connection with the antenna knob
98
.
In addition, in the antenna device
101
(FIGS.
32
A and
32
B), at the time when the rod antenna
102
is retracted, when the antenna knob
98
is pushed toward the retracting direction, the rod antenna
102
is shortened in such a way that the second antenna half part
85
is thrust into the first antenna half side
83
, and this shortened rod antenna
102
is thrust into inside the housing
61
for housing.
Incidentally, in this antenna device
101
, the rod antenna
102
, which has been shortened at this time, is electrically separated from the second helical antenna
71
.
In addition, in the antenna device
101
, at the time when the rod antenna
102
is pulled out, the antenna knob
98
is pulled toward the pulling direction so that the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, then the second antenna half part
85
is pulled out from the first antenna half part
83
to extend the rod antenna
102
, and this extended rod antenna
102
is pulled outside from the upper surface
97
A of the antenna cover for the helical
97
, and this rod antenna
102
as well as the second helical antenna
71
forms a compound antenna.
Thus, in the cellular telephone
100
, at the time when the rod antenna
102
is thrust, this rod antenna
102
is shortened so as to be thrust inside the housing
61
so that the portion of this rod antenna
102
to be thrust inside the housing
61
can be remarkably shortened compared with the cellular telephone
95
(
FIGS. 31A and 31B
) according to the above described fifth practical embodiment.
Accordingly, in this cellular telephone
100
, even in the case where the rod antenna
102
can hardly be thrust inside the housing
61
due to the space occupied by the battery, etc., this rod antenna
102
can be installed easily.
(8) Seventh Practical Embodiment
FIGS. 34A and 34B
, in which the same numerals as in
FIGS. 31A and 31B
are given to show the corresponding portions, show a cellular telephone
105
according to the seventh practical embodiment, which is configured as in the cellular telephone
95
(
FIGS. 31A and 31B
) according to the above described fifth practical embodiment except the configuration of the antenna device
106
.
In this antenna device
106
, a short-circuiting member
107
made of conductive member is provided at a predetermined location along the elongated direction of the rod antenna
70
so as to be brought into electrical and mechanical connection with this rod antenna
70
, and the above described rod antenna
70
is covered with the antenna cover for the rod
108
made of non-conductive member so as to expose the peripheral surface of this short-circuiting member
107
.
In addition, an excavation is gouged in the upper surface
97
A of the antenna cover for the helical
97
, and a terminal for the helical short-circuiting terminal
109
formed into a ring made of conductive member is fitted into the above described excavation. In addition, this terminal for the helical short-circuiting terminal
109
is brought into electrical and mechanical connection with the upper end of the second helical antenna
71
.
Thereby, in the antenna device
106
, at the time when the rod antenna
70
is retracted, the antenna knob
98
is pushed in the direction of retracting so as to be thrust onto the upper surface
97
A of the antenna cover for the helical
97
, and then, this antenna knob
98
is inserted into the terminal for the helical short-circuiting terminal
109
, the second helical antenna
71
and the antenna power supply terminal
77
, and thus the rod antenna
70
is electrically separated from the antenna power supply terminal
77
and housed inside the housing
61
.
In addition, in the antenna device
106
, at the time when the rod antenna
70
is pulled out, the antenna knob
98
is pulled in the direction of drawing so that the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, then this power supply member for the rod
72
is brought into electrical connection with the antenna power supply terminal
77
, and at the same time, the short-circuiting member
107
is brought into electrical connection with the terminal for the helical short-circuiting terminal
109
, and thus the upper end and the lower end of the second helical antenna
71
are short-circuited with the rod antenna
70
to form a compound antenna.
Here, in the antenna device
106
, under this state, at the time of transmission and at the time of reception, the transmission-reception circuit
41
supplies the first helical antenna
68
and the compound antenna with power sequentially via the unbalanced transmission line
42
and the balun
46
, so as to operate this first helical antenna
68
an antenna.
In addition, in the antenna device
106
, in the compound antenna, the electrical length of the second helical antenna
71
appears to change due to short-circuiting to the rod antenna
70
, and the resonance point toward the working frequency of this second helical antenna
71
shifts so as to cause only the rod antenna
70
to operate as an antenna without causing the second helical antenna
71
to operate as an antenna.
That is, in the antenna device
106
, the first helical antenna
68
and the rod antenna
70
are caused to operate as an antenna of approximately balanced type, and at this time, balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the rod antenna
70
to the ground side of the unbalanced transmission line
42
, and this prevents the leakage current from flowing from the ground side of the unbalanced transmission line
42
to the shield case so as not to cause the above described shield case to operate as an antenna.
Accordingly, in this cellular telephone
105
, at the time of transmission and at the time of reception, when the second helical antenna
71
or the compound antenna is used together with the first helical antenna
68
, the shield case is prevented from operating as an antenna and is caused to function only as the essential electrical shield plate and the ground, and thus deterioration of the antenna characteristics of this cellular telephone
105
in the vicinity of a human body can be remarkably reduced. In addition, the power absorbed by the human body from the shield case is controlled so that the SAR can be remarkably decreased.
(9) Eighth Practical Embodiment
FIGS. 35A and 35B
, in which the same numerals as in
FIGS. 34A and 34B
are given to show the corresponding portions, show a cellular telephone
110
according to the eighth practical embodiment, which is configured as in the cellular telephone
105
(
FIGS. 34A and 34B
) according to the above described seventh practical embodiment except the configuration of the antenna device
111
.
In
FIGS. 36A and 36B
in which the same numerals denotes the corresponding portions in
FIGS. 34A and 34B
as well as
FIGS. 33A and 33B
, the antenna device
111
has an elastic rod antenna
112
, in which a second antenna half part
85
is inserted through into a first antenna half part
83
in such a fashion so as to be able to be retracted and pulled out freely, and a short-circuiting member
113
is brought into electrical and mechanical connection with a predetermined location of the first antenna half
83
, and this first antenna half side
83
is covered with the antenna cover for the rod
114
made of non-conductive member so as to expose the peripheral surface of the short-circuiting member
113
.
In addition, in the antenna device
111
(FIGS.
35
A and
35
B), at the time when the rod antenna
112
is retracted, when the antenna knob
98
is pushed toward the retracting direction, the rod antenna
112
is shortened in such a way that the second antenna half part
85
is thrust into the first antenna half side
83
, and this shortened rod antenna
112
is thrust into inside the housing
61
for housing. Incidentally, in this antenna device
111
, the rod antenna
112
, which has been shortened at this time, is electrically separated from the second helical antenna
71
.
In addition, in the antenna device
111
, at the time when the rod antenna
112
is pulled out, the antenna knob
98
is pulled toward the pulling direction so that the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, then the second antenna half part
85
is pulled out from the first antenna half part
83
to extend the rod antenna
112
so that the power supply member for the rod
72
is brought into electrical connection with the antenna power supply terminal
77
and the short-circuiting member
113
is brought into electrical connection with the terminal for the helical short-circuiting terminal
109
, and thus the upper end and the lower end of the second helical antenna
71
are short-circuited with the extended rod antenna
112
, and a compound antenna is formed.
Thus, in the cellular telephone
110
, at the time when the rod antenna
112
is retracted, this rod antenna
112
is shortened so as to be thrust inside the housing
61
so that the portion of this rod antenna
112
to be thrust inside the housing
61
can be remarkably shortened compared with the cellular telephone
105
(
FIGS. 34A and 34B
) according to the above described seventh practical embodiment.
Accordingly, in this cellular telephone
110
, even in the case where the rod antenna
112
can hardly be thrust inside the housing
61
due to the space occupied by the battery, etc., this rod antenna
112
can be installed easily.
(10) Ninth Practical Embodiment
FIGS. 37A and 37B
, in which the same numerals as in
FIGS. 31A and 31B
are given to show the corresponding portions, show a cellular telephone
115
according to a ninth practical embodiment, which is configured as in the cellular telephone
95
(
FIGS. 31A and 31B
) according to the above described fifth practical embodiment except the configuration of the antenna device
116
.
In this antenna device
116
, a connecting section
117
made of non-conductive member is brought into mechanical connection with the upper end of the rod antenna
70
, and an antenna member
118
made of conductive member is brought into mechanical connection with this connecting section
117
, and moreover, this antenna member
118
is provided with an antenna knob
99
. Thereby, this rod antenna
70
and the antenna member
118
are brought into mechanical connection by the connecting section
117
, but are separated electrically.
In addition in the predetermined location in the upper surface
61
B of the housing
61
, a power supply member
119
for the helical, which is located inside the antenna cover for the helical
97
and is formed as a ring made of conductive member so as to be electrically separated from the antenna power supply terminal
77
, is disposed, and the lower end of the second helical antenna
71
is brought into electrical and mechanical connection with this power supply member
119
for the helical.
In addition, in this antenna device
116
, the rod antenna
70
is arranged to be inserted into the second helical antenna
71
and the power supply member
119
for the helical and the antenna power supply terminal
77
so as to be thrust and pulled out.
Actually, in this antenna device
116
, at the time when the rod antenna
70
is retracted, the antenna knob
98
is pushed in the direction of retracting so as to be thrust onto the upper surface
97
A of the antenna cover for the helical
97
, and then, the antenna member
118
is brought into electrical connection with the power supply member
119
for the helical and the antenna power supply terminal
77
, and thus this antenna member
118
is brought into electrical connection with the second helical antenna
71
, and thus this antenna member
118
and the second helical antenna
71
form a compound antenna.
Thereby, in this antenna device
116
, under this state at the time of transmission and at the time of reception, the transmission-reception circuit
41
, which supplies the first helical antenna
68
and this compound antenna with power sequentially via the unbalanced transmission line
42
and the balun
46
, operates these first helical antenna
68
and the compound antenna as an antenna of approximately balanced type, and at this time balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the compound antenna to the ground side of the unbalanced transmission line
42
, and thus prevents the shield case from operating as an antenna.
In addition, in the antenna device
116
, at the time when the rod antenna
70
is pulled out, the antenna knob
98
is pulled in the direction of drawing so that the protrusion
72
A of the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, then this power supply member for the rod
72
is brought into electrical connection with the antenna power supply terminal
77
, and the rod antenna
70
is brought into electrical contact with the balanced side of the balun
46
, and at the same time, the second helical antenna
71
is electrically separated from the balanced side of the balun
46
.
Thereby, in the antenna device
116
, under this state, at the time of transmission and at the time of reception, the transmission-reception circuit
41
provides the first helical antenna
68
and the rod antenna
70
with power sequentially via the unbalanced transmission line
42
and the balun
46
so as to operate this first helical antenna
68
and the rod antenna
70
as an antenna of approximately balanced type and at that time, balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the rod antenna
70
to the ground side of the unbalanced transmission line
42
, and thus prevents the shield case to operate as an antenna.
Accordingly, in this cellular telephone
115
, at the time of transmission and at the time of reception, when the compound antenna or the rod antenna
70
is used together with the first helical antenna
68
, the shield case is not caused to operate as an antenna but is caused to function only as the essential electrical shield plate and the ground, and thus deterioration of the antenna characteristics of this cellular telephone
115
in the vicinity of a human body can be remarkably reduced, and at the same time, the power absorbed by the human body from this shield case is controlled so that the SAR can be remarkably decreased.
(11) Tenth Practical Embodiment
FIGS. 38A and 38B
, in which the same numerals as in
FIGS. 37A and 37B
are given to show the corresponding portions, show a cellular telephone
120
according to the tenth practical embodiment, which is configured as in the cellular telephone
115
(
FIGS. 34A and 34B
) according to the above described ninth practical embodiment except the configuration of the antenna device
121
.
In
FIGS. 39A and 39B
in which the same numerals denotes the corresponding portions in
FIGS. 37A and 37B
as well as
FIGS. 33A and 33B
, the antenna device
121
has an elastic rod antenna
121
, in which a second antenna half part
85
is inserted through into a first antenna half part
83
in such a fashion so as to be able to be retracted and pulled out freely, and the antenna member
118
is provided in the upper end of the second antenna half part
85
via the connecting section
117
.
In addition, in the antenna device
121
(FIGS.
38
A and
38
B), at the time when the rod antenna
121
is retracted, when the antenna knob
98
is pushed toward the retracting direction, the rod antenna
121
is shortened in such a way that the second antenna half part
85
is thrust into the first antenna half side
83
, and this shortened rod antenna
121
is thrust into inside the housing
61
for housing, at this time, the antenna member
118
is brought into electrical connection with the power supply member
119
for the helical and the antenna power supply terminal
77
so that this antenna member
118
and the second helical antenna
71
form the compound antenna.
In addition, in the antenna device
121
, at the time when the rod antenna
121
is pulled out, the antenna knob
98
is pulled toward the pulling direction so that the protrusion
71
A of the power supply member for the rod
72
is thrust onto the antenna power supply terminal
77
, then the second antenna half part
85
is pulled out from the first antenna half part
83
to extend the rod antenna
121
to bring the power supply member for the rod
72
into electrical connection with the antenna power supply terminal
77
.
Thus, in the cellular telephone
120
, at the time when the rod antenna
121
is thrust, this rod antenna
121
is shortened so as to be thrust inside the housing
61
so that the portion of this rod antenna
121
to be thrust inside the housing
61
can be remarkably shortened compared with the cellular telephone
115
(
FIGS. 37A and 37B
) according to the above described ninth practical embodiment.
Accordingly, in this cellular telephone
120
, even in the case where the rod antenna
121
can hardly be thrust inside the housing
61
due to the space occupied by the battery, etc., this rod antenna
121
can be installed easily.
(12) Other Practical Embodiments
Incidentally, the above described first to tenth practical embodiments describe those cases where a micro-strip line
34
shown in
FIG. 12
is applied as the unbalanced transmission line
42
, but the present invention is not limited thereto, and otherwise various kinds of unbalanced transmission lines such as a coaxial cable
137
which is formed by a cylindrical external conductor
135
(that is, the ground side) as shown in
FIG. 40 and a
central conductor
136
(that is, the hot side) inserted into this external conductor
135
being insulated each other, and the like.
In addition, the above described first to tenth practical embodiments describe those cases where the phasing device
49
configured by assembling phasing circuits
50
shown in
FIG. 16
in the balun
46
shown in
FIG. 15
is arranged to be used, but the present invention is not limited thereto, and, as shown in
FIGS. 41A
to
41
C, with phasing devices such as the one configured by assembling T-type phasing circuits
138
in a symmetrical configuration in each of which two capacitive reactance elements C
3
and C
4
are brought into connection in series having their connection middle point P
2
with which one of inductive reactance element L
4
is brought into conductive connection, and the other end of the above described inductive reactance element L
4
is grounded, the one configured by assembling π-type phasing circuits
139
in a symmetrical configuration in each of which one ends of capacitive reactance elements C
5
and C
6
are respectively brought into conductive connection with one end and the other end of the inductive reactance element L
5
, and the other ends of the above described capacitive reactance elements C
5
and C
6
are grounded, and the one configured by assembling π-type phasing circuits
140
in a symmetrical configuration in each of which one ends of the inductive reactance elements L
5
and L
7
are respectively brought into conductive connection with one end and the other end of the capacitive reactance element C
7
, and the other ends of the above described inductive reactance elements L
6
and L
7
are grounded, the phase of the high frequency signals of which can be shifted around 180 degrees within the working frequency band, phasing devices in various kinds of configurations can be used.
Moreover, the above described first to tenth practical embodiments describes those cases where the balun
46
shown in
FIG. 15
is used, but the present invention is not limited thereto, and baluns other than this in various kinds of configurations can be used if they can prevent the leakage current from flowing form the antenna of approximately balanced type to the ground side of the unbalanced transmission line
42
.
Actually, as this kind of balun,
FIG. 42
shows a balun
142
in another configuration using the unbalanced transmission line
141
made of a coaxial cable, being configured by one end of the hot side
145
of the coaxial cable (this hereinafter to be referred to as a bypass line)
144
having an electrical length of a half wave length in the working frequency being brought into electrical connection with one end of the hot side of the unbalanced transmission line
141
and by one end of the ground side
147
of this bypass line
144
being brought into electrical connection with one end of the ground side
146
of the above described unbalanced line
141
. That is, the balun
142
in such configuration is the one in which the bypass line
144
having electrical length of a half wavelength instead of the phasing device
49
of the balun
46
shown in FIG.
15
.
In the balun
142
in such a configuration, the first antenna element of the antenna of approximately balanced type is brought into electrical connection with the one end of the hot side
143
of the unbalanced transmission line
141
, and the second antenna element of this antenna of approximately balanced type is brought into electrical connection with the other end of the hot side
145
of the bypass line
144
so that the high frequency signals sent out to the first antenna element via the hot side
143
of the unbalanced transmission line
141
are also sent out via the hot side
145
of the bypass line
144
to the second antenna element with the phase being shifted by around 180 degrees against the first antenna element, and thereby the leakage current is to be prevented from flowing from the second antenna element to the ground side
146
of the unbalanced transmission line
141
.
In addition, as this kind of balun, as shown in
FIG. 43
, there is the one, in which the first and second inductive reactance elements L
8
and L
9
and the first and second capacitive reactance elements C
8
and C
9
are connected sequentially alternately to form a ring, the hot side of the not-shown unbalanced transmission line is brought into electrical connection with the connecting middle-point P
3
between the first inductive reactance element L
8
and the second capacitive reactance element C
9
, the ground side of this unbalanced transmission line is brought into electrical connection with the connecting middle point
4
between the first capacitive reactance element C
8
and the second inductive reactance element L
9
, the first antenna element of the antenna of the not-shown approximately unbalanced type is brought into electrical connection with the connecting middle point P
5
between the first inductive reactance element L
8
and the first capacitive reactance element C
8
, and the second antenna element of the antenna of this approximately balanced type is brought into electrical connection with the connecting middle point P
6
between the second inductive reactance element L
8
and the second capacitive reactance element C
8
to configure so-called LG bridge balun.
In such configured balun
148
, with the first and second inductive reactance elements L
8
and L
9
having respectively the same value, and with the first and second capacitive reactance elements C
7
and C
8
having respectively the same value, the above described inductance L and the capacitance C are configuring the following equation:
(2 πf)
2
LC=1  (1)
and, the following equation:
{fraction (L/C)}=Z1Z2  (2)
and they are selected to fulfill those equations so that the high frequency signals given from the hot side of the unbalanced transmission line are sent out without any changes from the connecting middle point P
5
to the first antenna element, and these high frequency signals undergo phase shifting of around 180 degrees against the connecting middle point P
5
within the working frequency band, and the obtained high frequency signals with shifted phases are sent out from the connecting middle point P
6
to the second antenna element. Incidentally, Z1 represents impedance between the hot side and the ground side of the unbalanced transmission line, and Z2 represents impedance between the connecting points P
5
and P
6
. Moreover, f represents a working frequency.
In addition, such a balun
148
, which can be formed as a micro chip of around 1 mm cube as in the phasing device
49
of the balun
46
shown in the above described
FIG. 15
, can be easily installed in cellular telephones which tend to be miniaturized.
Moreover, as this kind of balun, as shown in
FIGS. 44A and 44B
, there are also a trans form balun
151
comprising an air-core coil
149
formed between the hot side and the ground side of the not-shown unbalanced transmission line and an air-core coil
150
formed between the first and second antenna elements of the antenna of approximately balanced type so that they are caused to face each other and a trans form balun
154
comprising an air-core coil
152
formed between the hot side of the unbalanced transmission line and the first antenna element of the antenna of approximately balanced type, and an air-core coil
153
formed between the ground side of the above described unbalanced transmission line and the second antenna element of the antenna of approximately balanced type so that they are caused to face each other.
In addition, as this kind of balun, as shown in
FIG. 45
, there is also a trans form balun
159
comprising an air-core coil
155
formed between the hot side of the not-shown unbalanced transmission line and the first antenna element of the antenna of approximately balanced type and an air-core coil
156
formed between the ground side of the above described unbalanced transmission line and the ground so that they are caused to face each other and comprising an air-core coil
157
formed between the above described ground side and the second antenna element of the antenna of this approximately balanced type, and an air-core coil
158
formed between the hot side and the ground so that they are caused to face each other.
Incidentally, in such a trans form balun
159
configured as shown above, impedance between the connecting terminals of the first and second antenna elements will be larger by around four times (4Z3) than the impedance Z3 between the hot side and the ground side of the unbalanced transmission line.
In addition, in the trans form baluns
151
,
154
, and
159
as shown in
FIGS. 44A and 44B
and
FIG. 45
, instead of the air-core coils
149
,
150
,
152
,
153
,
155
,
156
,
157
, and
158
, a pair of coils
163
and
164
formed by a multi-layer wiring substrate
160
, through-hole
161
and a conductive pattern
162
as shown in
FIG. 46
can be used.
In addition, the trans form baluns
151
,
154
, and
159
can be formed by micro-chips of around one to three (mm) cube in their entirety when coils formed by integrating conductor pattern are thus used, and therefore can be installed easily even in the case where the space is limited as in the above described LC bridge balun
148
(FIG.
43
).
In addition, as this kind of balun,
FIGS. 47A and 47B
show a balun
165
in another configuration where the unbalanced transmission line
141
made of a coaxial cable is used, in which the unbalanced transmission line
141
is inserted through the cylindrical conductor
166
so that one end
166
A of this cylindrical conductor
166
opens and the other end
166
B is short-circuited with the ground side
146
of this unbalanced transmission line
141
, which is also called as Sperrtophf balun or Bazooka balun.
In such configured balun
165
, the first antenna element of the antenna of approximately balanced type is brought into electrical connection with the hot side
143
of the unbalanced transmission line
141
in the open side (balanced side) of the cylindrical conductor
166
, the second antenna element of the antenna of approximately balanced type is brought into electrical connection with the ground side
146
of this unbalanced transmission line
141
, and the transmission-reception circuit
41
is brought into electrical connection with the hot side
143
and the ground side
146
of the unbalanced transmission line
141
in the short-circuited side (unbalanced side) of the cylindrical conductor
166
.
In addition, in this balun
165
, since the cylindrical conductor
166
is selected to have electrical length of a quarter wave length of the working frequency, when the unbalanced side is looked at from the balanced side, in its entirety the unbalanced transmission line
141
becomes an inner conductor, and the cylindrical conductor
166
becomes an external conductor so as to give rise to a deemed transmission line of electric length of a quarter wave length in which one end is short-circuited so that the impedance becomes infinite against the leakage current and the leakage current can be prevented from flowing to the ground side
146
of the unbalanced transmission line
141
.
Incidentally,
FIG. 48
is to show a Sperrtopf balun
167
using the unbalanced transmission line
42
made of a micro-strip line becomes equivalent to the Sperrtopf balun
165
shown in
FIGS. 47A and 47B
to operate likewise with the hot side
44
being formed as a line
80
as to resemble the central conductor of the coaxial cable and with the ground side
45
being formed so as to resemble the external conductor of the coaxial cable and the sectional view of the cylindrical conductor.
In addition, as a balun of this kind,
FIG. 49
shows a balun
168
in anther configuration to be described by using the unbalanced transmission line
141
made of a coaxial cable, wherein the unbalanced transmission line
141
and a conductor (this hereinafter to be referred to as diverging conductor)
169
having electrical length of a quarter wave length are disposed so that the other ends thereof is trued up and one end of this diverging conductance
169
is brought into electrical connection with one end of the hot side
143
of the unbalanced transmission line
141
, and the other end of the above described diverging conductor
169
is brought into electrical connection with the opposite location of the ground side
146
of this unbalanced transmission line
141
for configuration.
In the balun
168
in such a configuration, the first antenna element is brought into electrical connection with the other end of the hot side
143
of this unbalanced transmission line
141
, and the second antenna element is brought into electrical connection with the other end of the ground side
146
of this unbalanced transmission line
141
, so as to give rise to a circuit equivalent to the baluns
165
and
167
shown in the
FIGS. 47A and 47B
, and
FIG. 48
described above, and to prevent the leakage current by making the impedance at the other end of the hot side
143
of the unbalanced transmission line
141
infinite as in these baluns
165
and
167
.
Moreover, the above described first to tenth practical embodiments describe those cases where the antenna of approximately balanced type is used, but the present invention is not limited thereto, and antennas of balanced type which are completely symmetrical structurally and electrically and antennas which are completely non-symmetrical structurally and electrically in a medium excited figure can be arranged to be used. Incidentally, in the case where an antenna in the medium excited figure is used, the voltage figures in the first and the second antenna elements are different, and therefore, the baluns
165
,
157
, and
168
shown in
FIG. 47A
to
FIG. 49
described above are to be used so that the leakage current can be prevented from flowing form the first or the second antenna element to the ground side of the unbalanced transmission line.
Moreover, the above described first to tenth practical embodiments describe the case where the first and the second helical antennas
68
and
71
with conductive line member being rolled spirally for forming are to be used, but the present invention is not limited thereto, and various kinds of antenna elements other than this, as shown in
FIGS. 50A and 50B
, such as the helical antenna
173
formed by the multi-layer wiring substrate
170
, the through hole
171
, and the conductor pattern
172
and the antenna element
176
with a conductor pattern
175
meandering on one surface
174
A of the circuit substrate
174
for formation, and the like can be arranged to be used.
In addition, instead of the first and the second helical antennas
68
and
71
, sheet antenna elements such as the above described thin line form antenna
94
, and as shown in
FIGS. 51A and 51B
, the antenna element
177
with a conductive film meandering for formation, and the antenna element
178
squarely formed with conductive film and the like can be used inside or outside the housing
61
, and such antenna elements can be used to prevent the housing
61
from getting bigger.
Moreover, the first practical embodiment, the third to fifth practical embodiments, the seventh practical embodiment, and the ninth practical embodiment described above describe those cases where the rod antenna
70
made of a conductive stick form line member is arranged to be used, but the present invention is not limited thereto, and various kinds of antenna elements other than this, as shown in
FIG. 52
, such as tight coil
180
to be used as an antenna element in which a conductive line member is tightly coiled spirally for formation to electrically become a cylindrical conductor, or the antenna element, etc., to be used which is formed with a predetermined conductor on the circuit substrate and the like can be arranged to be used. Incidentally, this tight coil
180
can be used as an antenna element so as to prevent destruction thereof even if it is bent when it is pulled out from the housing
61
.
Incidentally, this tight coil
180
can be used as the first antenna half part
83
in the above described second and sixth practical embodiments, and the eighths and tenth practical embodiments, and when used as this first antenna half part
83
, destruction thereof can be prevented as described above even if it is bent when it is pulled out from the housing
61
.
Moreover, the above described second, sixth, and tenth practical embodiments describe the case where the antenna section
82
in which elastic rod antenna is installed as shown in FIGS.
27
A. and
27
B and the elastic rod antennas
102
and
121
shown in
FIGS. 33A and 33B
FIGS. 39A and 39B
are arranged to be used, but the present invention is not limited thereto, and the antenna section
181
, in which an elastic rod antenna is installed so as to be configured as in
FIGS. 53A and 53B
, in which the same numerals as in
FIGS. 27A and 27B
are given to show the corresponding portions, the elastic rod antenna
182
, which is configured as in
FIGS. 54A and 54B
, in which the same numerals as in
FIGS. 33A and 33B
are given to show the corresponding portions, and the elastic rod antenna
183
, which is configured as in
FIGS. 55A and 55B
, in which the same numerals as in
FIGS. 39A and 39B
are given to show the corresponding portions can be arranged to be used.
Actually, in the antenna section
181
shown in
FIGS. 53A and 53B
, the power supply member for the rod
72
is brought into electrical and mechanical connection with the lower end of the second antenna half side
85
, and the upper end is inserted into the cavity of the first antenna half part
83
and is brought into electrical and mechanical connection with the sliding spring
86
. In addition, the stopper against overdrawing
84
is installed in the lower end of the first antenna half part
83
, and the upper end is brought into electrical and mechanical connection with the power supply member for the helical
74
via the connecting section
184
made of non-conductive member. In addition, this first antenna half part
83
is covered with the antenna cover for the rod
185
. Thereby, the antenna section
181
can form an elastic rod antenna with the first and the second antenna half parts
83
and
85
as in the antenna section
82
of the above described second practical embodiment.
In addition, in the rod antenna
182
shown in
FIGS. 54A and 54B
, the power supply member for the rod
72
is brought into electrical and mechanical connection with the lower end of the second antenna half part
85
, and the upper end is inserted through the cavity of the first antenna half part
83
and is brought into electrical and mechanical connection with the sliding spring
86
. In addition, the stopper for overdrawing
84
is installed in the lower end of the first antenna half part
83
and the antenna knob
98
is installed in the upper end thereof. Thereby this rod antenna
182
will be also configured to be elastic because of the first and the second antenna half parts
83
and
84
as in the above described sixth practical embodiment.
Moreover, in the rod antenna
183
shown in
FIGS. 55A and 55B
, the power supply member for the rod
72
is brought into electrical and mechanical connection with the lower end of the second antenna half part
85
, and the upper end is inserted through the cavity of the first antenna half part
83
and is brought into electrical and mechanical connection with the sliding spring
86
. In addition, the stopper for overdrawing
84
is installed in the lower end of the first antenna half part
83
and the upper end thereof is brought into mechanical connection with the connecting section
117
. Thereby this rod antenna
183
will be also configured to be elastic because of the first and the second antenna half parts
83
and
84
as in the above described tenth practical embodiment.
Moreover, the above described first to tenth practical embodiments describe the case where the antenna section
67
and
82
, and the rod antennas
70
,
102
,
112
, and
121
are arranged to be installed in such a fashion so as to be thrust and pulled out freely approximately in parallel along the box elongated direction, but the present invention is not limited thereto, and as in
FIG. 56
in which the same numerals as in
FIGS. 22
are given to show the corresponding portions, the antenna section
67
(or antenna section
82
, the rod antenna
70
,
102
,
112
, and
121
) can be arranged to be installed in such a fashion so as to be retracted and pulled out freely along the inclined direction from the side of the back surface
61
C of the upper surface
61
B of the housing
61
to the box elongated direction on the side of the front surface
61
A in the lower surface
61
D.
Thereby, even if the cellular telephone approaches the head of a user when the antenna sections
67
and
82
and the rod antennas
70
,
102
,
112
, and
121
are pulled out, these antenna sections
67
and
82
and rod antennas
70
,
102
,
112
, and
121
can be kept further remote from the head, and thus deterioration of the antenna characteristics of the cellular telephone in the vicinity of a human body can be further reduced.
Moreover, the above described first to tenth practical embodiments, as described in the principle, describe the case where a matching circuit is provided between the transmission-reception circuit
41
and the balun
46
or between the balun
46
and the first and second antenna elements, but the present invention is not limited thereto, and as shown in
FIG. 57
, the matching circuits
187
and
186
can be arranged to be provided in the balanced side as well as the unbalanced side of the balun
46
.
In addition, as in
FIG. 58
, in which the same numerals as in
FIGS. 24A and 24B
are given to show the corresponding portions, the matching circuits
187
of the unbalanced side of the balun
46
can be arranged to be divided into two matching circuits
187
A and
187
B for forming, with one matching circuit
187
A being disposed between the unbalanced side of the balun
46
and the second switch
79
and with the other matching circuit
187
B being disposed between the second switch
79
and the transmission-reception circuit
41
.
Moreover, the above described first to tenth practical embodiments describe the case where balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the second antenna element to the ground side of the unbalanced transmission line
42
, but the present invention is not limited thereto, and such an arrangement can be made that the connection of the first and second antenna elements toward the terminal of the balanced side of the balun
46
is switched so that this balanced-to-unbalanced transforming function of the balun
46
prevents the leakage current from flowing from the first antenna element to the ground side of the unbalanced transmission line
42
.
Moreover, the above described third practical embodiment describes the case where the first helical antenna
68
has its first central axis to approximately correspond with the elongated line of the second central axis of the second helical antenna
71
and the rod antenna
70
to be disposed to insert therethrough, but the present invention is not limited thereto, and as in
FIG. 59
, in which the same numerals as in
FIGS. 28A and 28B
are given to show the corresponding portions, in the antenna device
189
, the first helical antenna
68
can be arranged so that the first central axis is disposed approximately in parallel along the elongated line of the second central axis of the second helical antenna
71
. Thereby, the antenna device
189
can be configured simply without necessity to implement complicated positioning to cause the rod antenna
70
to insert through the first helical antenna
68
.
Moreover, the above described fourth practical embodiment describes the case where the sheet line antenna
94
is arranged to be stuck on the inner side of the upper surface
61
B of the housing
61
, but the present invention is not limited thereto, and as in
FIG. 60
, in which the same numerals as in
FIGS. 29A and 29B
are given to show the corresponding portions, in the antenna device
190
, when the sheet line antenna
191
can hardly be stuck only on the inner part of the upper surface
61
B of the housing
61
due to its electrical length, etc., such an arrangement can be made that one end side of this sheet line antenna
191
is stuck for example on the inner side of the upper surface
61
B of the housing
61
, and the other end side of this sheet line antenna
191
is stuck, in a fashion so as to be bent, on the inner side of the side surface
61
E of this housing
61
.
Moreover, the above described first and second practical embodiments, and the fourth to tenth practical embodiments describe the case where the first helical antenna
68
has the first central axis to be disposed approximately in parallel with the perpendicular direction and the sheet line antenna
94
has its elongated direction to be disposed approximately in parallel along the perpendicular direction of the box, but the present invention is not limited thereto, and such an arrangement can be made that the first helical antenna
68
has the first central axis to be inclined against the perpendicular direction of the box for disposition, and in addition the film form line antenna
94
has its elongated direction to be inclined against the perpendicular direction of the box for disposition.
Moreover, the above described fifth to tenth practical embodiments describe the case where the second helical antenna
71
is disposed so that the rod antennas
70
,
102
,
112
, and
121
are thrust and pulled out along the second central axis, but the present invention is not limited thereto, and the second helical antenna
71
can be arranged to be disposed to have the second central axis approximately in parallel along the elongated direction of the rod antenna
70
,
102
,
112
, and
121
. Thereby, the antenna device can be configured simply without necessity to implement complicated positioning to cause the rod antenna
70
,
102
,
112
, and
121
to insert through the second helical antenna
71
.
Moreover, the above described first to tenth practical embodiments describe the case where the present invention is arranged to be applicable to the cellular telephones
60
,
80
,
90
,
92
,
95
,
100
,
105
,
110
,
115
,
120
but the present invention is not limited thereto, and can be applied to various kinds of portable wireless devices other than this, such as portable wireless equipment for receiving purposes only and the cellular phones of cordless telephones, and the like.
Moreover, the above described first to tenth practical embodiments describe the case where the balun
46
is arranged to be applied as balanced-to-unbalanced transformation means for implementing balanced-to-unbalanced transforming function between the unbalanced transmission line and the first and second antenna elements, but the present invention is not limited thereto, and various kinds of balanced-to-unbalanced transformation means other than this such as the above described various kinds of baluns can be widely applied if they can implement balanced-to-unbalanced transforming function between the unbalanced transmission line and the first and second antenna elements.
Moreover, the above described first to tenth practical embodiments describe the case where the first and the second switch device
78
and
79
are applied as the switching means for selectively switching connections of the unbalanced transmission line with the first and the second antenna elements and with only the first antenna element so that at the time of reception, the first and second antenna elements are brought into connection with the unbalanced transmission line via the balanced-unbalanced transmission line, or only the first antenna element is brought into connection with the unbalanced transmission line, but the present invention is not limited thereto, and various kinds of switching means other than this can be widely applied if they can selectively switch connections of the unbalanced transmission line with the first and the second antenna elements and with only the first antenna element so that, at the time of reception, the first and second antenna elements are brought into connection with the unbalanced transmission line via the balanced-unbalanced transmission line, or only the first antenna element is brought into connection with the unbalanced transmission line.
While there has been described in connection with the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be aimed, therefore, to cover in the appended claims all such changes and modifications as fall within the true spirit and scope of the invention.
Claims
- 1. An antenna device of a diversity reception system, comprising:a first antenna element installed so as to be retracted and pulled out freely; a fixed second antenna element; an unbalanced transmission line for supplying said first and second antenna elements with power; balancing-unbalancing transformation means for implementing balancing-unbalancing transformation action between said unbalanced transmission line and said first and second antenna elements; and switching means for selectively switching connections of said unbalanced transmission line with said first and second antenna elements and with only said first antenna element so that, at the time of reception, said first and second antenna elements are brought into connection with said unbalanced transmission line via said balancing-unbalancing transformation means, or only said second antenna element is brought into connection with said unbalanced transmission line, wherein said switching means are arranged to bring said unbalanced transmission line into connection with said the first and second antenna elements via said balancing-unbalancing transformation means so that said unbalanced transmission line supplies said first and second antenna elements with power via said balancing-unbalancing transformation means so as to operate said first and second antenna elements as an antenna.
- 2. The antenna device according to claim 1, whereinsaid switching means causes said first and second antenna elements to operate as an antenna at the time of transmission, when said unbalanced transmission line is brought into connection with said first and second antenna elements via said balancing-unbalancing transformation means so that said unbalanced transmission line supplies said first and second antenna elements with power.
- 3. The antenna device according to claim 2, whereinsaid first antenna element has a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element is configured by a spiral-formed fixed helical antenna to be disposed so that a central axis of a spiral is made approximately perpendicular to an elongated direction of said rod antenna.
- 4. The antenna device according to claim 2, whereinsaid first antenna element has a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element is configured by a spiral-formed fixed helical antenna to be disposed so that said rod antenna is thrust and pulled out along a central axis of a spiral of said helical antenna.
- 5. The antenna device according to claim 2, whereinsaid first antenna element has a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element is configured by a spiral-formed fixed helical antenna to be disposed so that a central axis of said rod antenna is to be approximately perpendicular to an elongated direction of said rod antenna.
- 6. The antenna device according to claim 2, whereinsaid first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element comprises a first spiral-formed fixed helical antenna, and further comprising a second spiral-formed fixed second helical antenna, wherein at least one end of said second helical antenna is brought into electrical connection with said rod antenna so that a compound antenna is formed when said rod antenna is retracted or pulled out.
- 7. The antenna device according to claim 6, whereinsaid second helical antenna is disposed so that said rod antenna is thrust or pulled out along a central axis of a spiral of said helical antenna.
- 8. The antenna device according to claim 6, whereinsaid second helical antenna is disposed so that a central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.
- 9. The antenna device according to claim 6, whereinsaid rod antenna is formed of elastic material so as to comprise a conductive cylindrical member having a cavity through which a conductive stick form member is inserted.
- 10. A portable radio set having an antenna device of a diversity reception system, wherein said antenna device comprises:a first antenna element installed so as to be retracted and pulled out freely; a fixed second antenna element; an unbalanced transmission line for supplying said first and second antenna elements with power; balancing-unbalancing transformation means for implementing balancing-unbalancing transformation action between said unbalanced transmission line and said first and second antenna elements; switching means for selectively switching connections of said unbalanced transmission line with said first and second antenna elements and with only said first antenna element so that, at the time of reception, said first and second antenna elements are brought into connection with said unbalanced transmission line via said balancing-unbalancing transformation means, or only said second antenna element is brought into connection with said unbalanced transmission line; and said switching means are arranged to bring said unbalanced transmission line into connection with said the first and second antenna elements via said balancing-unbalancing transformation means so that said unbalanced transmission line supplies said first and second antenna elements with power via said balancing-unbalancing transformation means so as to operate said first and second antenna elements as an antenna.
- 11. The portable radio set according to claim 10, whereinin said antenna device, said switching means cause said first and second antenna elements to operate as an antenna at a time of transmission, when said unbalanced transmission line is brought into connection with said first and second antenna elements via said balanced-unbalanced transmission line by means of said switching means so that said unbalanced transmission line supplies said first and second antenna elements with power via said balancing-unbalancing transformation means.
- 12. The portable radio set according to claim 11, whereinsaid first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element is configured by a spiral-formed fixed helical antenna, and is disposed so that a central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.
- 13. The portable radio set according to claim 11, whereinsaid first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element is configured by a spiral-formed fixed helical antenna, and is disposed so that said rod antenna is thrust or pulled out along a central axis of a spiral of said helical antenna.
- 14. The portable radio set according to claim 11, whereinsaid first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element is configured by a spiral-formed fixed helical antenna, and is disposed so that a central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.
- 15. The portable radio set according to claim 11, whereinsaid first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and said second antenna element comprises a first spiral-formed fixed helical antenna, and further comprising a second spiral-formed fixed second helical antenna, wherein at least one end of said second helical antenna is brought into electrical connection with said rod antenna so that a compound antenna is formed at a time when said rod antenna is retracted or pulled out.
- 16. The portable radio set according to claim 15, whereinsaid second helical antenna is disposed so that said rod antenna is thrust or pulled out along a central axis of a spiral of said helical antenna.
- 17. The portable radio set according to claim 15, whereinsaid second helical antenna is disposed so that said central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.
- 18. The portable radio set according to claim 15, whereinsaid rod antenna is formed of elastic material so as to comprise a conductive cylindrical member having a cavity through which a conductive stick form member is inserted.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-224265 |
Aug 1999 |
JP |
|
US Referenced Citations (3)