| 摘要 |
PURPOSE:To improve the distortion factor and modulation degree by comparing a signal being the sum of a reference voltage signal and a modulation wave signal with a detection signal so as to obtain a control signal, thereby quickening the response. CONSTITUTION:A carrier frequency signal inputted to an input terminal of an amplitude modulator 1 is modulated by using a modulation signal Em supplied to other input terminal. The output signal P1 is amplified at an amplifier 2 by an amplification factor Gv in response to a control signal Ec inputted from the amplifier 3. The output signal P0 is sent to an antenna 5 via an output detector 4. The output detector 4 applies a detection voltage signal ET obtained by detecting the output signal of the amplifier 2 to one input terminal of the comparison amplifier 3. Moreover, the modulation wave signal Em is supplied to the other input terminal of the amplifier 3 via a capacitor 7. A reference voltage E0 from a DC voltage signal generator 8 is applied to the amplifier 3 via a resistor 9. The amplifier 3 controls the gain of the amplifier so that the detection signal ET is equal to a reference signal EO+Em.
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