| 摘要 |
<p>A demodulator which has broad band characteristics, is low in distortion and power consumption and small in characteristic variations with respect to variations in temperature and changes with time, and can be improved in demodulating performance; and which comprises a 5-port junction circuit that receives a reception signal and a local signal to generate three signals having phase difference, and detects respective signal levels (amplification components) of these signals to obtain three power detection signals (base band signals) (P1, P2, P3), a first multiplier for multiplying a detection signal (P1) by a factor (A1) for offsetting the square components of a interference signal and a local signal, a second multiplier for multiplying a detection signal (P2) by a factor (A2) for offsetting the square components of a interference signal and a local signal, a first subtractor for subtracting the first multiplication result from the the detection signal (P2), a second subtractor for subtracting the second multiplication result from the detection signal (P3), and a multi-port signal/IQ signal conversion circuit for converting output signals from the first and second subtractors into an in-phase signal (I) and an orthogonal signal (Q) that are demodulation signals.</p> |
