| 摘要 |
PURPOSE: A pre-distorter of a power amplifier is provided, which can reduce a fabrication cost by removing IMD(Inter Modulation Distortion) components of many dimensions in a minimum space. CONSTITUTION: A cubic IMD path part generates a cubic order IMD component from an input signal, and a higher order IMD path part generates a fifth and seventh order IMD component from the input signal. A carrier path part performs a gain amplification of a carrier component from the input signal, and a power combiner cancels the cubic order component by mixing the cubic order IMD component and the higher order IMD component. An amplitude/phase control part(41,42) controls amplitudes and phases of the cubic order IMD being output from the cubic order IMD path part and the IMD whose cubic order IMD is cancelled in the higher order IMD path part by considering a distortion during an output of a main amplifier. A power combiner(44) combines an IMD signal being output from the amplitude/phase control part and a signal being output from the carrier path part.
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