发明名称 |
RFI DETECTOR |
摘要 |
An interference wave detection circuit is designed so as to detect whether a beat due to the difference between two carrier wave frequencies is included or not in a received signal for a radio receiver. The detection circuit comprises circuitry for deriving a first binary signal corresponding to a level of a signal of voice frequency band obtained by demodulating the received signal and for deriving a second binary signal corresponding to a level of an envelope signal of an intermediate frequency signal from the received signal to provide a predetermined time difference between the first and second binary signals. The detection circuit further comprises a spoken message detection circuit for detecting that a carrier wave is modulated in a spoken message of the received signal, and a correlation detection circuit for detecting correlation between the first and second binary signals when the output of the spoken message detection circuit is not produced, thereby producing an interference detection signal when the correlation therebetween is detected. |
申请公布号 |
AU567265(B2) |
申请公布日期 |
1987.11.12 |
申请号 |
AU19840037189 |
申请日期 |
1984.12.28 |
申请人 |
NEC CORP. AND NIPPON TELEGRAPH & TELEPHONE CORP. |
发明人 |
KOUZOU KAGE;HIROSHI WATANABE |
分类号 |
G01R29/00;H04B1/10;H04B7/26;H04B17/00;H04Q7/28;(IPC1-7):H04B7/14;H04B15/00 |
主分类号 |
G01R29/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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