Patent ID: 7395039

Claim:
A transmitter comprising: modulated signal generating means for generating a modulated signal; amplitude extracting means for extracting an amplitude component from the modulated signal generated by the modulated signal generating means; amplitude amplifying means having a feedback circuit and for amplifying the amplitude component extracted by the amplitude extracting means; voltage converting means for voltage-converting the amplitude component amplified by the amplitude amplifying means; control means for outputting a control signal according to a signal related to a level of the amplitude component of the modulated signal generated by the modulated signal generating means; voltage adjusting means for outputting the amplitude component voltage-converted by the voltage converting means, said amplitude component being changed by the control signal from the control means; and a radio-frequency power amplifier where the modulated signal is inputted to a radio-frequency modulated signal input terminal, the amplitude component outputted from the voltage adjusting means is inputted to a supply voltage terminal, and a modulated wave is outputted as a result, wherein of the amplitude component returning from an output terminal of the radio-frequency power amplifier to the amplitude amplifying means through the voltage adjusting means and the feedback circuit, a high frequency component that affects a characteristic of a closed loop by the feedback circuit of the amplitude amplifying means is suppressed by the voltage adjusting means according to the control signal.