| 摘要 |
PROBLEM TO BE SOLVED: To greatly improve the power efficiency of a distortion compensating amplifier circuit with simple constitution. SOLUTION: A directional coupler 7 couples so that the amplitude of an object signal from a delay circuit 6 is larger than the amplitude of an object signal from a main amplifier 5 and the signals are opposite in phase from each other and then a detection signal inputted to an auxiliary amplifier 10 includes the object signal. The main amplifier 5 and auxiliary amplifier 10 have distortion characteristics set nearly equal to each other and then the gradient of the amplitude frequency characteristic of a distortion component has a little variation before and after the detection signal is amplified by the auxiliary amplifier 10. When the output signal from the auxiliary amplifier 10 and the signal from the delay circuit 12 are coupled by a directional coupler 11 and then outputted from an output terminal 2, the object signals can be coupled in an in-phase state while distortion components are coupled in an opposite phase state while having nearly the same amplitude, so the power efficiency can greatly be improved without lowering the distortion removing performance. COPYRIGHT: (C)2004,JPO
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