| 摘要 |
PURPOSE:To simplify a carrier recovery circuit in a demodulator and to improve a bit error rate characteristic. CONSTITUTION:A modulator is provided with a balance mixer receiving two carriers whose phases differ by 90 deg. respectively and modulating them with P and Q channel signals and with a synthesizer synthesizing an output signal of the balance mixer and part of a carrier signal. Furthermore, A demodulator is provided with a carrier recovery circuit using a band pass filter 5 to extract the carrier component from the input modulation wave signal and recovering a demodulation carrier signal, with a phase shifter 3 shifting the carrier signal by 90 deg. and with balance mixers 2C, 2D receiving the carrier signals whose phase differ by 90 deg. and demodulating the P and Q channel signals from demodulation signals branched into two. |
