Information
-
Patent Grant
-
6496150
-
Patent Number
6,496,150
-
Date Filed
Friday, June 29, 200122 years ago
-
Date Issued
Tuesday, December 17, 200221 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 343 702
- 343 700 MS
- 343 725
- 343 729
- 343 749
- 343 750
- 343 751
- 343 850
- 343 853
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International Classifications
-
Abstract
An electronic device having multiple antennas and capable of operating in a wireless communication system, where interference between the multiple antennas is minimized using a detuning circuit activated by one or more antennas and resulting in detuning of at least one of the antennas. Activation of the detuning circuit can be accomplished by positioning an antenna to complete the detuning circuit and thereby activate the detuning circuit.
Description
FIELD OF THE INVENTION
The present invention relates to an electronic device having multiple antennas and, more particularly to an electronic device for reducing interference between the multiple antennas by engaging a decoupling electronic circuit for the electronic device operable in a wireless communication system.
BACKGROUND OF THE INVENTION
A communication system is operable to communicate information between a transmitting station, also referred to as a calling party, and a receiving station, also referred to as a receiving or called party, by way of a communication network. Operation of a wireless communication system transfers information between the transmitting and receiving stations via one or more base stations. These transmitting and receiving stations are also known as wireless communication devices, cell phones or mobile phones, Personal Digital Assistants (PDA's), or portable computers. As the capability and sophistication of the wireless communication system has increased, the demand for mobile communication devices having at least two antennas has proliferated. Previous mobile communication devices having multiple antennas utilize an electrical or mechanical switch to provide an RF signal to one of the multiple antennas, thereby providing an active antenna. However, the non-active antennas on the mobile communication device can degrade the performance of the active antenna. Among the concerns for locating multiple antennas within a limited space of a mobile communication device is the interference, or coupling between the antennas. Typical solutions include greater separation between the antennas to minimize the interference. Consequently, the relatively small dimensions of the mobile communication device restricts the available separation of the antennas. It would be useful to provide decoupling, also called detuning, or changing resonant frequency, of multiple antennas of a mobile communication device, while achieving sufficient gain and impedance matching of the antennas.
SUMMARY OF THE INVENTION
The present invention encompasses an electronic device having multiple antennas detuned to minimize interference and operable in a wireless communication system, where the electronic device can comprise a mobile station, a personal digital assistant (PDA) or a portable computer. The apparatus of the present invention comprises an internal antenna, an exterior antenna, and a detuning circuit to alter resonant frequency of the inactive antenna and thereby minimize interference between the antennas. Detuning circuitry may cooperate with either the interior antenna or the exterior antenna to minimize interference during operation of the electronic device. In addition, activation of the detuning circuit can be by achieved by positioning the exterior antenna to cooperate with the detuning circuit.
A more complete appreciation of all the advantages and scope of the present invention can be obtained from the accompanying drawings, the following detailed description of the invention and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an illustration of a mobile station block diagram representing an embodiment of the present invention.
FIG. 2
is a detuning circuit illustrating an embodiment of the present invention.
FIG. 3
is a detuning circuit illustrating an alternative embodiment of the present invention.
FIG. 4
is a detuning circuit illustrating an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1
is a block diagram representing an electronic device of the present invention where a mobile station
10
can be used in conjunction with an embodiment of the present invention. Generally, the mobile station
10
includes a receiver
20
, a transmitter
22
and a controller or processor
24
that is coupled to the receiver
20
and the transmitter
22
. The receiver
20
sends incoming messages to the processor
24
for analysis, whereas outgoing or originating messages are sent from the processor
24
to the transmitter
22
. These incoming and originating messages can be in the form of a voice message, a data message or a combination of voice and data messages.
User interface with the mobile station
10
can be accomplished via an input device
26
which may comprise: a Liquid Crystal Display (LCD)
28
which can contain a touch-screen display (not shown), or a Light Emitting Diode (LED) (not shown); a tone generator
30
; a speaker
32
; a vibrating device
34
; and a data entry device
36
. The data entry device
36
can be an alpha-numeric keypad (not shown) and the input device
26
further contains a microphone
38
capable of capturing a voice message. In addition, a timer
40
, also known as a clock chip, can be used for synchronizing the operations of the processor
24
and tracking time, a term well known to those of ordinary skill in the art of mobile stations. The mobile station
10
also includes a storage location, illustrated in the embodiment of
FIG. 1
as a memory
41
, where the memory
41
is capable of storing a plurality of constants and variables used by processor
24
in the operation of the mobile station
10
. Communication between the input device
26
, the tone generator
30
and the vibrating device
34
is assured by coupling these devices to the processor
24
.
In an embodiment according to the invention, the mobile station
10
contains a first antenna
42
, a second antenna
44
and a detuning circuit
46
. The detuning circuit
46
in accordance with the invention minimizes interference between the first and second antennas,
42
and
44
respectively. The first antenna
42
and the second antenna
44
are capable of transmitting and receiving communication signals in any number of communication frequencies, for example: Global System for Mobile Communication (GSM), Personal Communication System (PCS), Global Positioning System (GPS), Bluetooth, Code Division Multiple Access (CDMA) and W-CDMA. Antennas
42
and
44
can also function as dual-band (i.e. CELL/PCS), tri-banded, quad-banded etc. antennas. An embodiment of the present invention includes the antennas
42
and
44
used as transceivers for data, voice and GPS applications.
In a preferred embodiment, the first antenna
42
is a whip antenna, and the second antenna
44
is an internal antenna. An increase in performance of the antennas
42
and
44
, specifically gain and impedance matching, results when using the detuning circuit
46
to alter the resonant frequency of the antenna
42
or
44
, connected to the detuning circuit
46
.
FIG. 2
illustrates an embodiment of the present invention wherein the second antenna
44
comprises an internal antenna acted upon by the detuning circuit
46
. A first digital signal
48
, also designated as control
1
, an RF feed
50
and a second digital signal
52
, also designated as control
2
, provide inputs to the detuning circuit
46
. In an embodiment of the present invention, the second digital signal
52
is the inverse of the first digital signal
48
. The detuning circuit
46
further contains a first capacitor
54
, a second capacitor
56
, a third capacitor
58
, a fourth capacitor
60
, an inductor
62
, a first switch
64
, a second switch
66
and first ground
68
. In a preferred embodiment, capacitors
54
,
56
and
60
are DC decoupling capacitors and switches
64
and
66
can be either an FET (Field Effect Transistors) switch or a MEMS RF (Micro Electromechanical System) switch. Activation of the second antenna
44
entails closing the first switch
64
, and opening the second switch
66
. Deactivation of the second antenna
44
entails opening the first switch
64
and closing the second switch
66
, thereby engaging the inductor
62
in cooperation with the third capacitor
58
to detune the second antenna
44
by changing the resonance of the second antenna
44
. Use of the detuning circuit
46
acts to minimize interference between the first antenna
42
and the second antenna
44
.
FIG. 3
illustrates another embodiment of the present invention wherein the second antenna
44
comprises an internal antenna acted upon by the detuning circuit
146
. A first digital signal
148
, also designated as control
1
, an RF feed
150
and a second digital signal
152
, also designated as control
2
, provide inputs to the detuning circuit
146
. In an embodiment of the present invention, the second digital signal
152
is the inverse of the first digital signal
148
. The detuning circuit
146
further contains a fifth capacitor
154
, a sixth capacitor
156
, a seventh capacitor
158
, an eighth capacitor
160
, a third switch
164
, a fourth switch
166
and a second ground
168
. In a preferred embodiment, capacitors
154
,
156
,
158
and
160
are DC decoupling capacitors and switches
164
and
166
can be either an FET (Field Effect Transistors) switch or a MEMS RF (Micro Electromechanical System) switch. Activation of the second antenna
44
entails closing the third switch
164
, and closing the fourth switch
166
. Deactivation of the second antenna
44
entails opening the third switch
164
and opening the fourth switch
166
, thereby removing the connection of the second ground
168
to the second antenna
44
. By removing the connection of the second antenna
44
to the second ground
168
the antenna
44
is described as “floating”, and thereby detuned. This detuning acts to minimize interference between the first antenna
42
and the second antenna
44
.
Note that the embodiments described in FIG.
2
and
FIG. 3
describe a detuning circuit,
46
and
146
respectively, acting upon the second antenna
44
, wherein switches
64
and
66
must oppose one another (i.e. when switch
64
is closed switch
66
must be open) in embodiment of FIG.
2
. However, switches
164
and
166
must act in tandem (i.e. when switch
164
is closed switch
166
must be closed) in embodiment of FIG.
3
. In a preferred embodiment the detuning circuits
46
and
146
are activated when the antenna
42
is manipulated to a pre-set position, such as extension of a whip antenna. In distinction to the above embodiments,
FIG. 4
, described below, involves decoupling the first antenna
42
to minimize interference between the first antenna
42
and the second antenna
44
.
FIG. 4
illustrates another embodiment of the present invention wherein the first antenna
42
comprises an extendible whip antenna acted upon by a third detuning circuit
208
. A PCB (Printed Circuit Board)
202
contains the first antenna
42
, the second antenna
44
, a connector
204
attached to the first antenna
42
, a clip
206
, the third detuning circuit
208
and conduit
210
to connect the third detuning circuit
208
to the clip
206
. Operation of the first antenna
42
to a retracted position causes the connector
204
to communicate with the conduit
210
and engage the third detuning circuit
208
. A shunt inductor circuit forms the third detuning circuit
208
to detune the first antenna
42
and minimize interference between the first antenna
42
and the second antenna
44
.
It is understood that various modifications can be made to the mobile station apparatus and method of operation and remain within the scope of the present invention. For example, the protective enclosure may comprise an external or internal antenna to assist transmission and reception of wireless signals.
While preferred embodiments have been discussed and illustrated above, the present invention is not limited to these descriptions or illustrations, and includes all such modifications, which fall within the scope of the invention and claim language presented below.
Claims
- 1. An electronic device capable of operation in a wireless communication system, the electronic device comprising:a first antenna having a first position and a second position, wherein said first antenna is capable of positioning between said first position and said second position; a second antenna in communication with said first antenna; and a detuning circuit for decoupling interaction between the first and the second antenna, thereby reducing interference between said second antenna and said first antenna, wherein said detuning circuit is activated when said first antenna is in said first position.
- 2. The electronic device as claimed in claim 1, wherein said second antenna is an internal antenna.
- 3. The electronic device as claimed in claim 2, wherein said internal antenna comprises a PIFA (Planar Inverted F-antenna).
- 4. The electronic device as claimed in claim 2, wherein said internal antenna comprises a patch antenna.
- 5. The electronic device as claimed in claim 2, wherein said internal antenna comprises a loop antenna.
- 6. The electronic device as claimed in claim 1, wherein said first position comprises a substantially extended position.
- 7. The electronic device as claimed in claim 1, wherein said detuning circuit comprises a first switch and a second switch, wherein positioning of said first switch is opposite the positioning of said second switch.
- 8. The electronic device as claimed in claim 7, wherein said first switch comprises a Micro Electromechanical System RF (MEMS RF) switch.
- 9. The electronic device as claimed in claim 7, wherein said second switch comprises a Micro Electromechanical System RF (MEMS RF) switch.
- 10. The electronic device as claimed in claim 1, wherein said detuning circuit comprises a first switch and a second switch, wherein positioning of said first switch is unified with the positioning of said second switch.
- 11. An electronic device capable of operation in a wireless communication system, the electronic device comprising:a first antenna having a contact portion located generally adjacent a terminus of said first antenna, wherein said first antenna is positioned between a first position and a second position; a second antenna in communication with said first antenna; and a detuning circuit for reducing interference between said second antenna and said first antenna, wherein said detuning circuit is activated upon engaging said contact portion of said first antenna when positioned in said first position.
- 12. The electronic device as claimed in claim 11, wherein said first position comprises a substantially extended position.
- 13. The electronic device as claimed in claim 11, wherein said contact portion comprises a clip.
- 14. The electronic device as claimed in claim 11, wherein said detuning circuit comprises a shunt inductor.
- 15. The electronic device as claimed in claim 11, wherein said second antenna is an internal antenna.
- 16. A method of decoupling multiple antennas of an electronic device capable of operation in a wireless communication system, the steps comprising:positioning a first antenna in a first position; establishing communication between a detuning circuit and a second antenna; and activating said detuning circuit upon said first antenna positioning to said first position, whereby interference is reduced between said first antenna and said second antenna.
- 17. The method as claimed in claim 16, further comprising:inputting a first digital signal, a second digital signal and an RF signal to said detuning circuit.
- 18. The method as claimed in claim 16, wherein:establishing communication between said detuning circuit and said second antenna follows the combination of closing a first switch and opening a second switch.
- 19. The method as claimed in claim 16, whereinactivating said detuning circuit upon said first antenna positioning to said first position follows the combination opening a third switch and opening a fourth switch.
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A |
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A |
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6211830 |
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B1 |
6225951 |
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