| 摘要 |
PROBLEM TO BE SOLVED: To continuously compensate a nonlinear characteristic of an amplifier, without causing deterioration in the characteristics, when switching active/ standby for a digital broadcast modulation signal. SOLUTION: A compensation device 103 in operation obtains an input amplitude versus output amplitude characteristic and an input amplitude versus output phase characteristic from an output signal of an amplifier 122, obtains compensation data from reverse characteristics to them and adds compensation data to an output signal of an ALC(auto level controller) 102. Then the compensation device 103 in operation informs a standby compensation device 113 in a real time about the obtained compensation data, and the compensation device 113 adds the informed compensation data to an output signal of an ALC 112 for the standby period. Moreover, the ALCs 102, 112 are provided to the pre-stages of the compensation devices 103, 113 and the ALCs 102, 112 adjust the amplitude value of the input signal to the compensation devices 103, 113 as set amplitude.
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