摘要 |
PURPOSE: To discriminate ID signals by frequency discrimination with simple circuit constitution. CONSTITUTION: A transmitter 1 for outputting transmission ID frequency signals f1 and a receiver 2 for inputting the transmission ID frequency signals are provided. The receiver is provided with multipliers 9a and 9b for respectively multiplying the received transmission ID frequency signals with the orthogonal signals of reference ID frequency signals f2 , low-pass filters 10a and 10b for passing through low-band frequency components from the output of the multipliers, squaring circuits 11a and 11b for respectively squaring the output of the low-pass filters and an addition circuit 12 for adding the output of the squaring circuits. This ID signal discrimination circuit is provided with reference signal generators 3 and 19, frequency dividers 4 and 20 for inputting reference signals from the reference signal generators and performing frequency division and setting switches 5 and 21 for supplying the frequency division ratio of the frequency dividers so as to respectively generate the transmission ID frequency signals and the reference ID frequency signals.
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