| 摘要 |
PURPOSE:To automatically obtain a pulse duration lengthening output with contennous phase and free of deviation in the carrier frequency by providing a delay feedback composite loop having an automatic phase controlling circuit automatically controlling the quantity of phase shifting of the loop. CONSTITUTION:An automatic phase controlling circuit (APC circuit) AC consisting of a phase detector 7, a sample holding circuit 8 and an APC loop filter 9 is added to a delay feedback composite loop RL consisting of a pulse width limiter 1, a delay line 2, a superimposition circuit 3, a gate switch 5, and a variable phase shifter 6. The phase difference between a signal b obtained by the supply of an input signal 101 to a pulse width limiting circuit 1 and a signal c delaying by passing through the loop RL more than once is detected by the phase detector 7, and the variable phase shifter 6 is controlled so that the phase difference becomes zero. The above described phase detector 7 produces a detection signal 105 only in a period where the signal a is superimposed on the signal c likewise a signal d, and is sustained in a predetermined period in the circuit 8. The output of this circuit 8 passes through the circuit 9 and becomes a control signal 113 corresponding to the sample level, thus the phase shifter 6 being controlled. |
