| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication device for individually attenuating voltage levels to a plurality of signals in which frequencies approximate each other. SOLUTION: The communication device for capturing a plurality of reception signals having different frequencies by one antenna has: an intermodulation oscillator for outputting a signal having a first frequency; an addition section for adding the reception signal to the signal having the first frequency; an intermodulation wave generation means for generating an intermodulation wave signal from the added reception signal and the signal having the first frequency; a local oscillator for outputting a local signal; a mixer for generating an intermediate frequency signal by mixing the local signal to the intermodulation wave signal; a BPF for taking out a desired signal from the intermediate frequency signal; a voltage level detection section for detecting a voltage level of the desired signal; and a control section for allowing the intermodulation oscillator to output the signal having the first frequency when a voltage level of the desired signal is higher than the saturation level of the reception section, and for generating the intermediate frequency signal by mixing the local signal of which the frequency is controlled to the intermodulation wave signal. COPYRIGHT: (C)2009,JPO&INPIT
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