Detection of pager signal in FM radio transmission
    1.
    发明授权
    Detection of pager signal in FM radio transmission 失效
    在FM无线电传输中检测寻呼机信号

    公开(公告)号:US5568655A

    公开(公告)日:1996-10-22

    申请号:US338034

    申请日:1994-11-14

    IPC分类号: G08B3/10 H04H20/34 H04B1/00

    摘要: Apparatus for detecting the presence of a paging signal at 57 KHz in a frequency modulated transmission includes a phase locked loop (14) which is sensitive to the presence of a pager signal. The phase locked loop (14) which produces phase adjusting pulses at a repetition rate representative of the presence or absence of a pager signal. The phase adjusting pulses are fed to a detector (22) which produces a bistable signal which is either low, indicating no pager signal, or high, indicating the presence of a pager signal.

    摘要翻译: 用于在频率调制传输中用于检测在57KHz的寻呼信号的存在的装置包括对寻呼信号的存在敏感的锁相环(14)。 锁相环(14)以表示寻呼机信号存在或不存在的重复频率产生相位调整脉冲。 相位调整脉冲被馈送到检测器(22),该检测器产生双稳态信号,其为低电平,不指示寻呼机信号,或高电平,指示寻呼机信号的存在。