PURPOSE: To prevent a spread of a spectrum accompanying the intermittency of a high frequency signal and control the level of the high frequency signal by controlling the gain of a variable gain amplifier and controlling the level of the output high frequency signal.
CONSTITUTION: The high frequency signal is switched with the composite signal H of a reference signal and the signal of the component of the difference between a reference waveform and the signal obtained by amplifying the output signal envelope detected by a signal detecting circuit DT through the variable gain amplifier with an optional gain, performing feedback control. A waveform shaping circuit WS performs waveform shaping so that the spread of the spectrum of the switched high frequency signal appearing at an output terminal is reduced sufficiently, so the spread of the spectrum of the high frequency signal made into a burst. Further, a high frequency switching circuit controls the gain of the VGA with a level control signal to control the level of the switched high frequency signal.
SAITOU TOSHIYUKI
KURITA OSAMU
OGAWA HIROTSUGU
NIPPON TELEGRAPH & TELEPHONE