| 摘要 |
PURPOSE:To facilitate spectrum controlling of carrier frequency band by detecting difference between actually obtained waveform spectrum and reference waveform in output of a keying element and synthesizing with reference waveform. CONSTITUTION:When a driving signal is impressed to the driving signal terminal DV of a non-linear keying element, a waveform shaping circuit WS is so adjusted that reference waveform that can drive the element to make the spread of waveform spectrum obtained in the output terminal OUT narrowest can be obtained. A differential amplifier DFA detects the difference between actually obtainable waveform spectrum and reference waveform in output of the keying element SW, and synthesize it with reference waveform by a synthesizing circuit H. By this way, feedback control is made to obtain ideal waveform from an output terminal OUT and to make output of the differential amplifier DFA small. |
