| 摘要 |
PURPOSE:To eliminate the effect of variation of the burst time and to attain a normal operation with a phase locked characteristic by providing a frequency control means containing an ON/OFF control function to a phase locked loop which is formed in response to the burst type signal input. CONSTITUTION:The intermittent phase error signal produced in response to the burst type signal input is compared with a prescribed reference level through binary identifying circuits 17-21. Then binary level signals are produced from these circuits 17-21. A generating circuit 25 produces another prescribed binary level signal with the binary level signals produced from the circuits 17-21 used as triggers. Then frequency control circuits 26-28 supply the prescribed binary level signals and produce the frequency control signals to the voltage control oscillator via an integrating function. As a result, the oscillation frequency of the voltage control oscillator is always controlled normally to the input carrier wave regardless of the variance of the burst time. Thus the normal function is secured to the demodulation characteristics. |
