| 摘要 |
PURPOSE:To regenerate stably a reference carrier by eliminating the need for a circuit doubling an input signal and constituting a regnerating circuit mainly with a PLL circuit so as to attain ease of large scale integration. CONSTITUTION:A 2-phase PSK modulating wave A from an input terminal 1 is inputted to an exclusive ORed EOR gate 2, and when another inputted signal F is (0), the modulating wave A is outputted as B as it is, and when the signal F is at (1), the modulating wave A is outputted after inversion. The outputted signal B is inputted to a phase comparator 41 of a PLL circuit 4 and one input of an EOR gate 51 of an inversion detecting circuit 5. Further, an output signal C of a VCO 43 of the circuit 4 is applied to another input of the gate 51 and an output signal D of the gate 51 is applied to an FF 52. Further, a signal G having a frequency twice that of the signal C from the VCO 43 is applied to the FF 52, which is reset at the rise of the signal G, and an output E of the circuit 5 is applied to an FF 3. Moreover, the output of the FF 3 is used as a signal F, a circuit doubling the input signal is not used for a demodulating device, and the reference carrier is regenerated stably with simple constitution. |
