| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a modulation circuit device, modulation method and radio communication device in which a desired signal can be obtained even when a transistor used as an amplitude modulator of a modulator for polar modulation is not a transistor that has linearity over a wide range. <P>SOLUTION: The present invention comprises: an angle modulator 2 for angle-modulating a phase signal 6 to be inputted; waveform shaping means 3, 11 in which, (1) when the magnitude of an amplitude signal 5 to be inputted becomes smaller than a first prescribed value, a waveform of the amplitude signal 5 is shaped so that the magnitude of the amplitude signal 5 of the portion which becomes small becomes the first prescribed value; and/or (2) when the magnitude of the amplitude signal 5 to be inputted becomes larger than the second prescribed value which is larger than the first prescribed value, the waveform of the amplitude signal 5 is shaped so that the magnitude of the amplitude signal 5 of the portion which becomes larger becomes the second prescribed value; and an amplitude modulator 4 for amplitude-modulating the signal from the output of the angle modulator 2 by the signal from the output of the waveform shaping means3, 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
