发明授权
- 专利标题: Antenna circuit
- 专利标题(中): 天线电路
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申请号: US09357128申请日: 1999-07-20
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公开(公告)号: US06456832B1公开(公告)日: 2002-09-24
- 发明人: Wasuke Yanagisawa , Shozaburo Kameda , Ryo Horie , Haruhisa Uchida , Junichi Imai , Yuichi Kagoshima
- 申请人: Wasuke Yanagisawa , Shozaburo Kameda , Ryo Horie , Haruhisa Uchida , Junichi Imai , Yuichi Kagoshima
- 优先权: JP9-007383 19970120; JP9-161952 19970604; JP9-211402 19970722
- 主分类号: H04B118
- IPC分类号: H04B118
摘要:
An antenna circuit which is improved the deterioration of amplitude characteristic in a strong electric field, an antenna circuit for AM broadcasting which can surely inhibit and damp FM-band signals in the strong electric field and amplifies to output AM-band signals, and an antenna circuit for AM/FM broadcasting in which AM-band signals are not damped by means of an FM-band filter. In the first antenna circuit, the output signal of an antenna (10) is supplied to the base of a transistor Tr2 forming a current amplification type amplifier having a high-input and low-output impedance and the emitter of the transistor Tr2 is grounded through a coil L6 and connected to an FM receiver (16) through a band-pass filter (38). In the second antenna circuit for receiving AM broadcasting, an input terminal is connected to an AM amplifier circuit (36) through coils (L7) and L8 in series and to the gate G of a field effect transistor FET. The source S of the transistor FET is grounded and the connecting point of the coils L7 and L8 is grounded through a capacitor C15 and a coil L9 in series. The second antenna circuit inhibits and damps FM-band signals in a plurality of steps. In the third antenna circuit for AM/FM broadcasting, the output signal of an antenna is divided into two parts and one part is supplied to an FM-band filter (12) through a serial FM resonance circuit (30) composed of capacitors and coils. The other part of the output signal is supplied to an AM-band filter (34).
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