Patent ID: 6931237

Claim:
A communication apparatus, a transmit frequency fT and a receive frequency fR of which has a difference fDD, said communication apparatus comprising: a first oscillator for generating a first oscillation signal with an oscillation frequency N×(M×fDD), where N is an integer equal to or greater than one and M is an integer equal to or greater than two; a frequency converter receiving the first oscillation signal, for converting it to a first signal with an output frequency fTIF, where fTIF=(M+1)×fDD or fTIF=M×fDD, and to a second signal with an output frequency fRIF, where fRIF=M×fDD when fTIF=(M+1)×fDD, and fRIF=(M+1)×fDD when fTIF=M×fDD; a second oscillator with an oscillation frequency fCH, where fCH=fT±fTIF or fCH=fR±fRIF; a transmitting mixer for outputting a transmission signal with a frequency fT by receiving a baseband signal to be transmitted, the first signal with the frequency fTIF output from said frequency converter, and a signal with the frequency fCH output from said second oscillator; and a receiving mixer for outputting the baseband signal received by receiving a reception signal with a frequency fR, a signal with the frequency fCH output from said second oscillator, and the second signal with the frequency fRIF output from said frequency converter.