| 摘要 |
PROBLEM TO BE SOLVED: To enable strict standards regarding a transmitter noise in a reception frequency band to be satisfied, without shortening speech time or using an expensive circuit. SOLUTION: A voltage control type variable tuning filter 3, having a pass band and an attenuation band, is arranged between a modulator 1 and a power amplifier 5. In addition, a controller, which controls this variable tuning filter 3 so that the pass band of the voltage control type variable tuning filter 3 is within a transmission frequency band and the attenuation band is within a reception frequency band, is provided, constituted of a power detector 4, a phase detector 6, a dither generation circuit 7, a control circuit 8, an adder 9 and a sample and hold circuit 10. |
