| 摘要 |
PURPOSE:To eliminate an interference wave by using a signal detector which contains a phase synchronizing circuit and delivers the error voltage corresponding to the difference of frequency to a self-traveling oscillation frequency to obtain the coincidence between the center frequency of a tuning filter and the frequency of the interference wave. CONSTITUTION:A part of an interference wave and N pieces of signal waves 13 is supplied respectively to a signal detector 8 from a monitor terminal of a directional coupler 6 via an attenuator 7. The detector 8 consists of a phase synchronizing circuit and synchronizes with only the frequency of an interference wave having a high power level. Then the error voltage corresponding to the difference between the frequency of an oscillator and the synchronizing frequency is delivered to an error voltage processing circuit 9. The circuit 9 obtains the coincidence between the center frequency of a tuning filter 11 and the frequency of interference wave by means of a filter driver 10. As the filter 11 is an absorbing type filter, only the signal component 15 is supplied to a receiver 1. |
