Patent Application
20090224986
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2008-55350 filed on Mar. 5, 2008; the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a radio apparatus and an antenna device, and in particular to a radio apparatus and an antenna device having an antenna element formed on a casing material of the radio apparatus.
2. Description of the Related Art
It is generally known that a radio apparatus, e.g., a mobile phone has a built-in antenna device contained in a casing material these days instead of an antenna device that may be extended outside of the casing material, e.g., a whip antenna that used to be popular. The radio apparatus may enjoy improved design and operability by employing the built-in antenna. In recent years, however, as the radio apparatus is required to have multiple functions and high performances and to be downsized and slim at the same time, the antenna device faces difficulty in performing as required in a condition such as contained in limited space of the casing material.
In order to deal with the above difficulty, e.g., it has been developed to form a conductive pattern on a casing material of a radio apparatus by using a method of, e.g., plating and to feed the conductive pattern as an antenna. Such an antenna may generally be fed through a feed pin in contact with the conductive pattern, instead of a feed line soldered to the conductive pattern, as it should be taken into account that the casing material often made of plastic has limited heat-resistance.
There is a problem, however, that a relative position between a printed board on which an antenna feed circuit is mounted and the casing material may affect where to put the feed pin and may limit a degree of freedom, as the feed pin has to be put in a fixed direction. In addition, in order to simplify assembly work in a manufacturing process, it is preferable to reduce the number and the size of the feed pins as much as possible. It is not known how to solve the above problem or how to meet the above manufacturing process requirement.
An antenna built-in module formed by an antenna feed circuit and an antenna combined with each other is disclosed in Japanese Patent Publication of Unexamined Applications (Kokai), No. 2005-5866.
According to JP 2005-5866, the antenna built-in module has a circuit board on which a radio circuit is provided, a cover made of sheet metal arranged in such a way as to almost entirely cover the circuit board, and an exclusive shield case made of sheet metal arranged in such a way as to cover a specific area on the circuit board.
The cover is not limited to be made of sheet metal and may be shaped as a lid of a box made of plastic and provided with a conductive layer on a surface of the box lid. In that case, a portion of the conductive layer formed on an upper plate of the box lid may work as a radiation conductor, and a portion of the conductive layer formed on a side wall of the box lid may work as a feed conductor and a grounded conductor.
The antenna built-in module of JP 2005-5866 is configured in such a way that the conductive layer formed on the side wall of the box lid may connect the radio circuit provided on the circuit board to the conductive layer formed on the upper plate of the box lid made of plastic.
As it is generally known that a printed board of a radio apparatus, e.g., a mobile phone, on which an antenna feed circuit is provided and a casing material of the radio apparatus may hardly be formed as one piece, the antenna built-in module of JP 2005-5866 may not be applied to such a radio apparatus.
Accordingly, an object of the present invention is to feed an antenna element formed by a conductive pattern formed, e.g., plated, on a casing material by using a small number of short feed pins located with a high degree of freedom.
To achieve the above object, according to one aspect of the present invention, a radio apparatus including a printed board having an antenna feed circuit, a casing material provided with an antenna element, an antenna feed material, and an electric connection between the antenna feed circuit and the antenna element is provided. The antenna element is formed by a conductive pattern formed on a face of the casing material facing the printed board. The antenna feed material is arranged between the face of the casing material and the printed board. The electric connection connects the antenna feed circuit and the antenna element through the antenna feed material.
Hereinafter, embodiments of the present invention will be described in detail. In following descriptions, terms such as upper, lower, left, right, horizontal or vertical used while referring to a drawing shall be interpreted on a page of the drawing unless otherwise noted. A same reference numeral given in no less than two drawings shall represent a same member or a same portion.
A first embodiment of the present invention will be described with reference to
The first section 11 contains a radio circuit that is not shown and a printed board 15 in which a feed line formed by a conductive pattern that is not shown is provided. The radio circuit and the conductive pattern are called an antenna feed circuit together.
The upper piece 11a has an inner face facing the printed board 15, and a conductive pattern 11c is formed on the inner face of the upper piece 11a. More specifically, the inner face of the upper piece 11a is provided with an adhesive layer (not shown) made of dielectric material being different from the material of the upper piece 11a. The conductive pattern 11c may be plated through the adhesive layer.
Owing to existence of the adhesive layer, the upper piece 11a may be provided with the conductive pattern 11c no matter what kind of material the upper piece 11a is made of. Thus, the material of the upper piece 11a may be selected from reinforced dielectric material that is necessary for the radio apparatus 1 to be stiff and thinner.
The upper piece 11a may have a conductive pattern that is not shown and formed on an outer face of the upper piece 11a. The conductive pattern on the outer face may be connected to the conductive pattern 11c by turning around an edge of the upper piece 11a or though a via hole that is not shown and penetrates between the inner and outer faces of the upper piece 11a.
The upper section 11 contains an antenna feed material 16 arranged between the inner face of the upper piece 11a and the printed board 15. The antenna feed material 16 is made of nonconductive material, e.g., plastic, and has a feed conductor 16a shown by a dashed line. The feed conductor 16a may be formed, e.g., by being plated on a surface of the antenna feed material 16, or as a via hole that penetrates inside the antenna feed material 16.
An end of the feed conductor 16a that is nearer to the printed board 15 is connected to the antenna feed circuit (more specifically, the conductive pattern that is not shown) of the printed board 15 through a first feed pin 17. Another end of the feed conductor 16a that is nearer to the upper piece 11a is connected to the conductive pattern 11c through a second feed pin 18.
The first feed pin 17 and the second feed pin 18 are a means of electrical connection, generally called a spring pin, having a plunger through a spring arranged in a metallic pipe. A tip of the plunger may be pressed against a conductive face of the other party of connection so as to obtain electrical conduction.
The first feed pin 17 may be provided on the printed board 15 and the tip of the plunger may be pressed against the end of the feed conductor 16a that is nearer to the printed board 15. The first feed pin 17 may be provided on the antenna feed material 16 and connected to the end of the feed conductor 16a that is nearer to the printed board 15, and the tip of the plunger may be pressed against the antenna feed circuit of the printed board 15.
The second feed pin 18 may be provided on the antenna feed material 16 and connected to the end of the feed conductor 16a that is nearer to the upper piece 11a, and the tip of the plunger may be pressed against the conductive pattern 11c. The second feed pin 18 may be provided on the upper piece 11a and the tip of the plunger may be pressed against the end of the feed conductor 16a that is nearer to the upper piece 11a.
According to the above configuration, the conductive pattern 11c is connected to the antenna feed circuit of the printed board 15, and may be fed as, e.g., a monopole antenna. As shown in
The antenna feed material 16 may be formed in such a way that a short feed pin may be used as the second feed pin 18 after the antenna feed material 16 is arranged in place. As shown in
As being arranged in such a way as to fill space around the end portion of the first section 11 that is farther from the connection 13, the antenna feed material 16 may mechanically reinforce the first section 11.
A modification of the first embodiment will be described with reference to
An antenna feed material 16m is put on a face of the printed board 15 facing the inner face of the upper piece 11a of the first section 11. The antenna feed material 16m is made of nonconduct material, e.g., plastic, and has a feed conductor 16n shown by a dashed line. The feed conductor 16n may be formed, e.g., by being plated on a surface of the antenna feed material 16m, or as a via hole that penetrates inside the antenna feed material 16m.
An end of the feed conductor 16n that is nearer to the printed board 15 is connected to the antenna feed circuit of the printed board 15 through a connector 19. The connector 19 is a pair of connectors put on the antenna feed material 16m and the printed board 16n and joined to each other.
An end of the feed conductor 16n that is nearer to the upper piece 11a is connected to the conductive pattern 11c through the second feed pin 18.
According to the above modified configuration, the conductive pattern 11c is connected to the antenna feed circuit of the printed board 15, and may be fed as, e.g., a monopole antenna. The first section 11m may lack the first feed pin 17 included in the first section 11 shown in
According to the first embodiment of the present invention described above, a radio apparatus that may use a conductive pattern formed on a casing material as an antenna element may feed the antenna element through a small number of short feed pins located with a high degree of freedom.
A second embodiment of the present invention will be described with reference to
The conductive pattern 11c of the second embodiment, however, may be used as an antenna such as an inverted F antenna that may be fed and grounded at one and another portions of the antenna, respectively.
As shown in
As described above, the conductive pattern 11c may be used as an antenna of a type that may be fed and grounded at one and another portions of the antenna, respectively, by using the first feed pin 17, the feed conductor 16a and the second feed pin 18 formed by the pairs of the signal side and the ground side. The first feed pin 17 may be formed by a pair of short feed pins that are similar to the short feed pins of the first embodiment, and so may be the second feed pin 18.
A modification of the second embodiment will be described with reference to
As shown in
As described above, the conductive pattern 11c may be used as an antenna of a type that may be fed and grounded at one and another portions of the antenna, respectively, by using the connector 19, the feed conductor 16n and the second feed pin 18 formed by the pairs of the signal side and the ground side. The antenna feed connection shown in
The antenna that may be fed and grounded at one and another portions of the antenna is not limited to the above examples of the inverted F antenna or the folded monopole antenna having a grounded end.
Another modification of the second embodiment will be described with reference to
As shown on a left side of
As what is shown in
According to the modifications shown in
According to the second embodiment of the present invention described above, a radio apparatus that may use a conductive pattern formed on a casing material as an antenna element and partially grounded may feed and ground the antenna element through a small number of paired short feed pins located with a high degree of freedom.
A third embodiment of the present invention will be described with reference to
The conductive pattern 11c of the third embodiment, however, is formed by a pair of conductive patterns of a signal side and a ground side.
As shown in
As described above, each of the first feed pin 17, the feed conductor 16a, the second feed pin 18 and the conductive pattern 11c may be formed as a pair of the signal side and the ground side so as to form an antenna having a ground region on a face of the upper piece 11a. Although using an unbalanced current excited and distributed on the ground region as a main radiation source, an antenna may not have a sufficient size of a ground region on the printed board 15. Even in such a case, the ground region may be enlarged on the upper piece 11a so that the antenna gain may be improved. The antenna may be fed through paired short feed pins as similarly described with respect to the second embodiment.
A modification of the third embodiment will be described with reference to
As shown in
As described above, each of the connector 19, the feed conductor 16n, the second feed pin 18 and the conductive pattern 11c may be formed as a pair of the signal side and the ground side so as to form an antenna having a ground region on the face of the upper piece 11a. The antenna feed connection shown in
Another modification of the third embodiment will be described with reference to
According to the third embodiment of the present invention described above, an additional effect may be obtained that an antenna that may not have a sufficient size of a ground region in a printed board inside a casing material may certainly have a ground region on a face of the casing material.
A fourth embodiment of the present invention will be described with reference to
The first section 21m is formed by an upper piece 21a and a lower piece 21b both made of dielectric material and mechanically joined in a vertical direction. The first section 21m contains a printed board 25 on which a radio circuit is provided but is not shown. The radio circuit and a feed line 24 that will be mentioned later are called an antenna feed circuit together.
The upper piece 21a has an inner face facing the printed board 25, and conductive patterns 21s and 21g are formed on the inner face of the upper piece 21a. The conductive patterns 21s and 21g are formed by using a same method as the conductive pattern 11c is as described with reference to
An antenna feed material 26m made of nonconductive and heat-resistant material (e.g., liquid crystal polymer) is arranged between the inner face of the upper piece 21a and the printed board 25. The antenna feed material 26m may be provided on the face of the printed board 25 facing the inner face of the upper piece 21a as the antenna feed material 16m is as shown in
Feed pins 28s and 28g are provided on a face of the antenna feed material 26m facing the inner face of the upper piece 21a. Each of the feed pins 28s and 28g is a same as the second feed pin 18 described with reference to
As the antenna feed material 26m is made of heat-resistant material, tips of the signal side and the ground side of the feed line 24 may be soldered to the feed pin 28s and the feed pin 28g, respectively. Another end of the feed line 24 may be connected to the above radio circuit that is not shown through a conductive pattern formed in the printed board 25. The feed line 24 may be connected to the feed pins 28s and 28g through a conductive pattern formed on a face, or as a via hole, of the antenna feed material 26m by being soldered to the conductive pattern.
Tips of plungers of the feed pins 28s and 28g are pressed against and thus connected to the conductive patterns 21s and 21g, respectively. The feed pins 28s and 28g may be arranged on the upper piece 21a and connected to the conductive patterns 21s and 21g respectively, and the tips of the plungers may be pressed against the conductive patterns formed on the antenna feed material 26m to which tips of signal and ground sides of the feed line 24 are soldered.
According to the above configuration of the fourth embodiment, the conductive patterns 21s and 21g may be fed by being connected to the signal side and the ground side of the antenna feed circuit of the printed board 25. The conductive patterns 21s and 21g may be coupled to each other as a pair of the signal side and the ground side, and so may be the feed pins 28s and 28g, so as to form an antenna having a ground region on the face of the upper piece 21a as similarly described with respect to the third embodiment. Meanwhile, the number of necessary feed pins may be reduced in comparison with the third embodiment.
According to the above configuration of the fourth embodiment, an antenna that uses an unbalanced current excited and distributed in the ground region as a main radiation source may expand the ground region so as to improve the antenna gain, even if having an insufficient size of the ground region in the printed board 25. The antenna may be fed through the pair of the short feed pins 28s and 28g, as similarly described with respect to the previous embodiments.
If the conductive patterns 21s and 21g that are separate to each other are replaced by one consecutive conductive pattern 21c, a portion of the conductive pattern 21c is connected to the signal side of the antenna feed circuit, and another portion of the conductive pattern 21c is grounded. Thus, an antenna of a type fed at one portion and grounded at another portion may be formed, as similarly described with respect to the second embodiment, by including a reduced number of the feed pins in comparison with the second embodiment.
In
According to the fourth embodiment of the present invention described above, an antenna feed material made of heat-resistant material may be used so that the number of feed pins required for the configuration of the second or the third embodiment may be reduced.
A fifth embodiment of the present invention will be described with reference to
The above additional conductive pattern may be used for an application other than an application of the antenna formed by the conductive pattern formed on the casing material. That is, e.g., the former is applied to a mobile phone use and the latter is applied to a wireless local area network (WLAN) use.
The connection shown in
As shown on a left side of
As shown in a middle portion of
A tip of a signal side of the feed line 24 is soldered to the feed pin 28s as described with respect to the fourth embodiment, and is connected to the conductive pattern 21s through the feed pin 28s. The ground pattern 36 is connected to the conductive pattern 21g through the feed pin 28g, so as to form on the ground side a connection being almost equivalent to the connection shown in
As shown on a right side of
According to the above configuration of the fifth embodiment, only two feed pins are enough to feed the antenna formed on the antenna feed material 26m and the antenna formed on the upper piece 21a separately. Given a three-dimensional shape, the antenna feed material 26m may usually have an advantage over the upper piece 21a of an effective surface area on which antenna element patterns are formed. Thus, it seems appropriate in lots of cases, although not in every case, that antennas of systems using a relatively low frequency and a relatively high frequency are provided on the antenna feed material 26m and on the upper piece 21a, respectively.
As described above with respect to the fifth embodiment, the additional antenna element is added to the antenna feed material 26m on the basis of the configuration shown in
According to the fifth embodiment of the present invention described above, an additional antenna element may be provided on the antenna feed material so that the radio apparatus may have multiple functions.
The particular hardware or software implementation of the present invention may be varied while still remaining within the scope of the present invention. It is therefore to be understood that within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-55350 | Mar 2008 | JP | national |
