| 摘要 |
PROBLEM TO BE SOLVED: To automatically correct the frequency deviation of output power without circuit remodeling or partial addition by making the output power of a power amplifier constant, irrespective of the frequency of an input signal. SOLUTION: A CPU 9 performs control operation to set a channel to be measured and the reference voltage outputted by a reference voltage generation part 12 at the input of an APC part 14 is varied, so that the input signal to the CPU 9 reaches a specific APC set value. Then the current channel and the reference voltage, when the APC set value is reached, are stored in an EEPROM 10. Then, another channel is set, and the reference voltage is similarly stored in the EEPROM 10. After this operation is completed for all measurement channels, a primary function is obtained from the current channel and reference voltage. For transmission over respective channels, the reference voltage generation part 12 is controlled with the primary function to vary the reference voltage, the output of a DC detection part 13 is compared, and the direct current of an amplifier in a PA part 2 is controlled according to the difference from the reference voltage to hold the high-frequency signal level of the output of a directional coupler 6 invariably constant.
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