| 摘要 |
PURPOSE:To automatically detect the generation of interference by changing slowly a carrier frequency of a transmitter in a cordless telephone system. CONSTITUTION:A carrier frequency fC1 transmitted from a transmitter 1 is changed slowly by another low frequency signal fL1 and a beat frequency is changed slowly when any beat takes place. In such constitution above, a part of an output received an demodulated by a receiver 3 is branched and given to a peak level detector 15. The output is given further to a peak level detector 18 at the same time, compared with reference voltages VC1, VC2, the beat frequency produced by interference is changed slowly and a specific frequency decided by a band pass filter 14 appears without fail. The beat is detected by detecting it. |
