| 摘要 |
PURPOSE:To stably operate the subject pulse duration lengthening over a wide frequency range by providing a stable automatic phase control circuit automatically controlling the phase shifting quantity of a delay feedback composite loop in the pulse duration lengthening of pulse modulation wave using the delay feedback composite loop. CONSTITUTION:At the rear stage of a frequency converter 22 which uses the output of an electronic control oscillator 20 as a local signal, there is provided a delay feedback composite loop RL having an automatic phase control circuit (APC circuit) AC. A phase synchronous control circuit PLL controlling the local signal for the frequency converter 22 is provided in the loop RL, and the carrier component of the output 103 of the loop RL is controlled so that it phase-synchronized with the reference signal. Simultaneously, by the operation of the APC circuit the phase discontinuity within the pulse of the output 103 generated by mismatching of the delay time of the loop RL is synchronous-demodulated and detected by the delay circulation synchronizing after the side band wave component is phase-detected on the reference of the carrier wave component thereby to control a variable phase shifter 6 within the loop RL so that the phase discontinuity becomes zero. As a consequence, with respect to noise generated in the loop RL and external noise, the automatic phase control of the loop RL can be carried out stably. |
