| 摘要 |
PURPOSE:To provide a two-phase PSK demodulation circuit in which a two- phase PSK demodulation signal stabilized more than ever can be obtained. CONSTITUTION:This circuit is the two-phase PSK demodulation circuit constituted in an RDS receiver which reproduces RDS data from an RDS modulation signal in which a subcarrier is modulated by a signal two-phase PSK-modulated by the RDS data, and the product of the RDS modulation signal B and an RDS clock signal D is computed by inputting them to a multiplier means 2. The phase of the output signal E of the multiplier means 2 is compared with that of the synchronizing signal H of the subcarrier by inputting to a phase comparison means 3, and a phase comparison signal I is outputted. A pulse conversion means 5 outputs by converting a pulse included in the phase comparison signal I to the one with more fractionized periods. An integration and reset means 4 performs phase decision by observing a phase comprison signal I' pulse-converted at every period of the RDS clock signal D, and outputs the two-phase PSK demodulation signal F from which a subcarrier component is separated.
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