PURPOSE: To stably recover a carrier necessary for demodulating a PSK modulation signal by permitting a sample holding circuit to hold the control voltage of a voltage controlled oscillator VCO stable.
CONSTITUTION: While a synchronization detecting circuit 11 detects the synchro nization between the PSK modulation signal and the output signal of the VCO 10, a switch 14a at the input side of the sample holding circuit 14 is in an ON state, and a charge is charged and discharged to a capacitor 14b. While the input signal of the synchronization detecting circuit 11 is an FM modulation signal, the input side switch 14a is an OFF state, and the output of the sample holding circuit 14 becomes a constant voltage due to the charge of the capacitor 14b. the oscillation frequency of the output signal of the VCO 10 is controlled by the output voltage of the sample holding circuit 14. However, since the output voltage of the sample holding circuit 14 has less fluctuation, the output signal of the VCO 10 is stable. Accordingly, while the output signal of a band amplifier 8 is the PSK signal, the synchronization detecting circuit 11 can stably detect the synchronization at the beginning of said period.
| JPH01286531 | RANDOM ACCESS SYSTEM |
| JPS6256032 | ON-VEHICLE COMMUNICATION EQUIPMENT |
OTSUKA YOSHIMICHI
IZUMI YOSHINORI
GOSHI SEIICHI
KAYASHIMA HIROSHI
MITSUBISHI ELECTRIC CORP