| 摘要 |
<p>A receiver of the direct conversion system by which problems arising from interference between a reception signal and a local signal used by a quadrature demodulator on the reception side are moderated. When the carrier frequency of a transmission signal is represented by ft and the carrier frequency of a reception signal by fr while the frequency interval between the transmission and reception carrier frequencies is represented by fs (= fr - ft), first and second local oscillators generate first and second local signals fLO1, fLO2 having frequencies fLO1 APPROX ft - fs and fLO2 APPROX 2.fs, respectively. A mixer mixes the first and second local signals to generate an internal local signal which is a sum frequency component. The internal local signal is supplied to a quadrature demodulator of the reception side. The mixer and a band-pass filter are formed in the same LSI chip as the quadrature demodulator. <IMAGE></p> |
