Claims
- 1. An antenna device for a radio apparatus comprising:
- a) a first electrically insulating and a second electrically insulating band member, said first and second band members having respectively, a first conductor plate and a second conductor plate attached thereto, such that said first and second conductor plates are substantially insulated, and one end of each of said first and second band members is connected to said radio apparatus;
- b) a band connector attached to said first band member, for forming a loop of variable length by detachably connecting said first and second band members at one of a predetermined plurality of band connection positions, and having an electrode provided thereon such that when said first and second band members are connected by said band connector an overlap capacitance is formed between said electrode and said second conductor plate; and
- c) a resonance frequency compensation means operable for changing the magnitude of said overlap capacitance in proportion to a change in antenna inductance, wherein said change in antenna inductance is caused by change in antenna loop length.
- 2. The device of claim 1 wherein said resonance frequency compensation means includes an area changing portion on a side of said second conductor plate for changing the capacitance of said overlap capacitance by changing an opposing area between said electrode and said second conductor plate on the basis of the connecting position of said first and second band members.
- 3. The device of claim 2 wherein said first and second conductor plates each have a slit formed thereon in their lengthwise direction.
- 4. The device of claim 1 wherein said resonance frequency compensation means includes an effective-dielectric-constant changing portion on a side of said second band member, for changing the effective dielectric constant between said electrode and said second conductor plate on the basis of the connecting position of said first and second band members.
- 5. The device of claim 4, wherein said first and second conductor plates each have a slit formed thereon in their lengthwise direction.
- 6. The device of claim 1 wherein said resonance frequency compensation means includes a thickness changing portion on a side of said second band member, for changing the opposing distance between said electrode and said second conductor plate on the basis of the connecting position of said first and second band members.
- 7. The device of claim 6 wherein said first and second conductor plates each have a slit formed thereon in their lengthwise direction.
- 8. The device of claim 1 wherein said electrode comprises a conductive plate.
- 9. The device of claim 8 wherein said conductive plate comprises a metallic plate.
- 10. The device of claim 1 wherein said first and second conductor plates each have a slit formed therein in their lengthwise direction.
- 11. A wireless apparatus comprising an antenna which includes:
- a) a first electrically insulating and a second electrically insulating band member, said first and second band members having respectively, a first conductor plate and a second conductor plate attached thereto, such that said first and second conductor plates are substantially insulated, and one end of each of said first and second band members is connected to said radio apparatus;
- b) a band connector attached to said first band member, for forming a loop of variable length by detachably connecting said first and second band members at one of a predetermined plurality of band connection positions, and having an electrode provided thereon such that when said first and second band members are connected by said band connector an overlap capacitance is formed between said electrode and said second conductor plate; and
- c) a resonance frequency compensation means operable for changing the magnitude of said overlap capacitance in proportion to a change in antenna inductance, wherein said change in antenna inductance is caused by change in antenna loop length.
Priority Claims (5)
Number |
Date |
Country |
Kind |
63-196833 |
Aug 1988 |
JPX |
|
63-313340 |
Dec 1988 |
JPX |
|
1-167372 |
Jun 1989 |
JPX |
|
1-175168 |
Jul 1989 |
JPX |
|
4-240703 |
Sep 1992 |
JPX |
|
Parent Case Info
This application is a continuation in part of application Ser. No. 07/870,160 filed Apr. 15, 1992, now U.S. Pat. No. 5,243,356 issued Sep. 7, 1993, which is continuation of Ser. No. 07/477,867 filed Apr. 4, 1990, now abandoned.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
Country |
Parent |
477867 |
Apr 1990 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
870160 |
Apr 1992 |
|