| 摘要 |
PROBLEM TO BE SOLVED: To provide a broad-band distortion-compensated amplifier which has a simple circuit configuration, and is capable of detecting the frequency of input signals and surely making up for distortion. SOLUTION: Signals are inputted through an input terminal 11, and a part of the signals is extracted with a directional coupler 12 and inputted into a mixer 17. The mixer 17 mixes the input signals and local oscillation signals together and converts them into intermediate frequency signals IF. The intermediate frequency signals IF are extracted out through a high-pass filter 18 having sloping characteristics, and become signals that vary in amplitude according to frequency, and the signals are detected by a detecting circuit 19 and inputted into a control circuit 20. The control circuit 20 specifies the frequency of the input signals according to the level of the signals detected by the detecting circuit 19, and outputs a parameter Pa that is used for compensating optimally for distortion to a distortion-compensated amplifying circuit 13. The distortion-compensated amplifying circuit 13 compensates the signals which are inputted through the directional coupler 12 from the input terminal 11, for distortion using the parameter Pa outputted from the control circuit 20. COPYRIGHT: (C)2008,JPO&INPIT
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