Patent ID: 7251462
Filing Date: 2007-07-31
Classification: H03C,H03F,H04L

Abstract:
1. A modulation circuit device, comprising: an angle modulator of angle-modulating a phase signal to be inputted; a waveform shaping means in which, (1) when the magnitude of an amplitude signal to be inputted becomes smaller than a first prescribed value, a waveform of said amplitude signal is shaped so that the magnitude of said amplitude signal of the portion which becomes small becomes said first prescribed value, and/or (2) when the magnitude of said amplitude signal to be inputted becomes larger than said second prescribed value which is larger than said first prescribed value, the waveform of said amplitude signal is shaped so that the magnitude of said amplitude signal of the portion which becomes larger becomes said second prescribed value; a direct current voltage supply circuit of supplying a direct current voltage; a first amplitude modulator which operates on either of the operation modes of a first operation mode for amplifying the signal from the output of said angle modulator and a second operation mode for amplitude modulating the signal of the output of said angle modulator by the signal of the output of said waveform shaping means; and a second amplitude modulator which operates on either of the operation modes of a first operation mode for amplifying the output of said first amplitude modulator and a second operation mode for amplitude-modulating the signal of the output of said first amplitude modulator by the signal of the output of said waveform shaping means; wherein, when an output is made larger than a prescribed value by an output power, said first amplitude modulator is operated on said first operation mode with the signal from the output of said direct current voltage supply circuit controlled to be inputted, and said second amplitude modulator is operated on the second operation mode with the signal of the output of said waveform shaping means controlled to be inputted, wherein, when an output is made by an output power smaller than a prescribed value, said first amplitude modulator is operated on said second operation mode with the signal from the output of said waveform shaping means controlled to be inputted, and said second amplitude modulator is operated on the first operation mode with the signal of the output of said direct current voltage supply circuit controlled to be inputted.