| 摘要 |
PURPOSE:To attain stable operation without readjustment even when distortion is large or a power amplifier is changed by extracting only the distortion of the power amplifier, adjusting the amplitude and phase and combining the result with an intermediate frequency signal so as to adjust nearly automatically the distortion of the power amplifier. CONSTITUTION:An intermediate frequency signal is inputted from a terminal (a). A part of a signal distributor 25 extracts a part of the output of a high frequency power amplifier 10, a frequency converter 26 mixes it with a part of the high frequency local oscillating power from a local oscillator 24 and converts it again into an intermediate frequency signal. Further, a part of the intermediate frequency signal is extracted to form the intermediate frequency signal whose amplitude and phase are adjusted by an intermediate frequency variable amplitude device 39 and an intermediate frequency variable phase device 31, and a synthesizer 29 cancels the intermediate frequency signal and the intermediate frequency signal subject to re-conversion in the same amplitude and opposite phase thereby extracting the distortion component only included in the re-converted intermediate frequency signal, the distortion component is synthesized with the intermediate frequency signal by a signal synthesizer 21 via a distortion component variable amplitude device 38 and a distortion component variable phase device 37 so as to control the distortion component to be minimized.
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