| 摘要 |
PROBLEM TO BE SOLVED: To prevent bad influence on adjacent channels due to a change in temperature of a gain of a power amplifier, transmission of illegal radio waves due to a change in detection voltage of a detecting diode and communication failure, in a cartesian loop system transmitter in a radio device. SOLUTION: A forward direction gain control circuit 26 controls a variable attenuator 13 so that the temperature characteristic of a gain of a power amplifier 15 may be compensated on the basis of an output of a temperature sensor 27, and keeps distortion improvement amount constant. Also, a power control circuit 25 controls a variable attenuator 18 on the basis of the output of the temperature sensor 27, so that the temperature characteristic of the detection voltage of a detection diode 24 may be compensated, and keeps transmission power constant. COPYRIGHT: (C)2005,JPO&NCIPI
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