Patent Application
20100255893
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2009-93330 filed on Apr. 07, 2009; the entire contents of which are incorporated herein by reference.
1. FIELD OF THE INVENTION
The present invention relates to a mobile communication apparatus and an antenna structure, and in particular to a mobile communication apparatus configured to have two separate antennas.
2. DESCRIPTION OF THE RELATED ART
Mobile communication apparatuses (mobile phones, etc.) are required to be adapted for multiple radio frequency bands, such as 800, 1500 and 2000 MHz bands. Some communication service providers need not the 800 MHz band. In some cases, exact frequencies in the respective frequency bands are slightly different from one another.
A manufacturer of a mobile communication apparatus may consider, for a common design of the antennas, providing the apparatus with two separate antennas configured such that a first one of the two antennas is adapted for the 1500 and 2000 MHz bands and that a second one of the two antennas is adapted for the 800 MHz band positioned far apart from the other bands. Then, it is preferable to provide the mobile communication apparatus with a basic structure adapted for mounting both the first and second antennas thereon. Assuming that the second antenna is removed in accordance with a provider's specification that need not the second antenna, the apparatus should preferably be configured such that portions other than the second antenna are connected to one another without any change of design.
Further, the mobile communication apparatus should preferably agree with the provider's specification that requires slightly different frequencies in the respective frequency bands by slightly modifying the first or second antenna without modifying the main body of the apparatus. Further, the mobile communication apparatus should preferably agree with a structural specification of the main body that is more or less different depending on the provider by more or less modifying the first or second antenna in accordance with the difference.
Thus, the mobile communication apparatus should preferably be provided with a basic structure adapted for mounting both the first and second antennas, and needs no change of design even for a specification that need not the second antenna.
A mobile communication apparatus having an antenna adapted for multiple frequency bands is known, although not having an object of a common design, as disclosed in Japanese Patent Publication of Unexamined Applications (Kokai), No. 2008-72204. The mobile communication apparatus of JP 2008-72204 has an antenna 7 constituted by a first radiation element 8 (or 18) of an 800 MHz band (830-885 MHz) and a second radiation element 9 (or 13) of a 2 GHz band (1920-2170 MHz).
JP 2008-72204 does not disclose that the mobile communication apparatus is configured such that the second radiation element 9 (or 13) of the 2 GHz band and the first radiation element 8 (or 18) of the 800 MHz band are separate and can be removed. That may cause a problem that the design of the whole antenna 7 needs to be changed in order to remove, e.g., the first radiation element 8 (or 18) of the 800 MHz band.
Accordingly, an object of the present invention is to provide a mobile communication apparatus having a first antenna and a second antenna being separate from each other, and having a structure adapted for steadily connecting the both antennas to a feed point after the antennas are mounted, and for steadily connecting the first antenna to the feed point after the second antenna is removed and only the first antenna remains. Another object is to prevent interference and to increase a degree of freedom of parts arrangement by having the separate antennas.
To achieve the above object, according to one aspect of the present invention, a mobile communication apparatus configured to be provided with an extra antenna has a printed board provided with an antenna feed point, an antenna having a spring-like contact and provided on the printed board, and a housing constituted by a first case and a second case fixed into each other. The printed board and the antenna are arranged between and pressed by the first case and the second case. The antenna feed point and the spring-like contact are in contact with and electrically connected to each other by means of elastic force of the spring-like contact caused upon the first case and the second case being fixed into each other. The housing has a space for containing the extra antenna such that the extra antenna is electrically connected to the antenna feed point by means of the elastic force.
As shown in
As shown in
The first antenna 4 is formed by a metal plate and so on, and includes line lengths for 1500 and 2000 MHz bands. The second antenna 5 is formed by a thin film, has a metallic radiation element 5b printed on the film, and includes a line length for an 800 MHz band. The first antenna 4 is mounted in a direction parallel to a main face of the second case 20 and on a side close to a side face of the second case 20. The second antenna 5 is directed from the side face to the inside of the second case 20.
If the first case 1 and the second case 20 are fixed into each other, the feed point 3 on the printed board 2, the first contact 4a of the first antenna 4, the second contact 5a of the second antenna 5 and the sponge 6 are layered on top of one another under pressure in a direction perpendicular to the main face of the first case 1, and the feed point 3, the first contact 4a and the second contact 5a are electrically connected to one another.
Then, a portion including the second antenna 5 will be explained in detail.
The first antenna 4 is adapted for the 1500 MHz band and the 2000 MHz band. As having relatively short line lengths and being shaped to be small, the first antenna 4 is formed by a metal plate and so on, and arranged in a portion close to a side face of a housing constituted by the first case 1 and the second case 20 in a compact manner.
The second antenna 5 (indicated by hatching) is adapted for the 800 MHz band. As having a relatively long line length, the second antenna 5 is formed as a thin film-like antenna and can be arranged in a space inside the housing rather than in the portion close to the side face. Further, as the second antenna 5 is positioned apart from the first antenna 4 (e.g., opposite the first antenna 4 with respect to the feed point 3), interference between both the antennas can be prevented.
The second antenna 5 is formed by a thin film and provided with a wide area from a viewpoint of strength or handling. In that case, a portion of the second antenna 5 may possibly overlap an area of the shield plate 7 on the printed board 2. Even if they overlap each other, the metallic radiation element 5b extended from the second contact 5a of the second antenna 5 is formed by, e.g., being printed on the film in order not to overlap, or in order to keep clear of, the shield plate 7 in the direction perpendicular to the main face (or, perpendicular to the printed board 2), so that degradation of antenna performance can be prevented.
Then, the embodiment will be explained from a viewpoint of a common design. The first antenna 4 is adapted for the 1500 MHz band and the 2000 MHz band which are requisite frequency bands regardless of a provider's specification and requires a relatively small-sized antenna. Further, the portion close to the side face of the housing formed by the first case 1 and the second case 20 of the mobile communication apparatus 100 can be more or less commonly designed regardless of the provider's specification. Thus, the first antenna 4 should be arranged in the portion close to the side face of the first case 1 so that the shape of the first antenna 4 and the structure of the portion close to the side face of the housing can be commonly designed.
The second antenna 5 is adapted for the 800 MHz band that may be unnecessary in some cases depending on the provider's specification. Thus, the second antenna 5 is formed as a thin film-like antenna and can be mounted in a space inside the housing rather than in the portion close to the side face of the housing formed by the first case 1 and the second case 20 without a need of a large housing. The housing design can thereby be made common regardless of whether the second antenna 5 is mounted or not.
Then, condition of the connection among the feed point 3, the first contact 4a and the second contact 5a will be explained.
Although the first antenna 4, the second antenna 5 and the sponge 6 are mounted on and fixed to the second case 20 and then put on the first case 1 as described with reference to
The spring-like first contact 4a can be designed to produce sufficient elastic force even if the second antenna 5 is not mounted and the arrangement shown in
According to the embodiment of the present invention described above, the mobile communication apparatus having the first antenna and the second antenna being separate from each other can be configured such that both the antennas are mounted and steadily connected to the feed point. Further, even if the second antenna is removed and only the first antenna is mounted in the same configuration, the first antenna can be steadily connected to the feed point.
Although the sponge 6 is arranged between the second antenna 5 and the second case 20, the sponge 6 may be made of conductive material and arranged between the first antenna 4 and the second antenna 5. Further, the sponge 6 may be made of nonconductive material and arranged between the first antenna 4 and the second antenna 5 so that the first antenna 4 and the second antenna 5 are connected through a capacitive coupling.
Moreover, the present invention can be applied to a mobile phone, a PHS and other radio devices. The present invention can be applied to one of two housing sections of a flip type mobile phone.
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 |
|---|---|---|---|
| P2009-93330 | Apr 2009 | JP | national |
