Patent ID: 6515544
Filing Date: 2003-02-04
Classification: H01Q,H03F,H04B

Abstract:
A feed-forward multi-terminal power-combining power amplifier comprising:a plurality of input terminals and output terminals corresponding to a plurality of channels; a plurality of feed-forward amplifier circuits corresponding to the plurality of channels; an input-side multi-terminal power combiner supplied with transmission signals from said input terminals, for power-combining and dividing said transmission signals for input to said plurality of feed-forward amplifier circuits; and an output-side multi-terminal power combiner for power-combining and dividing the outputs from said feed-forward amplifier circuits of said plurality of channels and outputting signals to said output terminals of said plurality of channels; wherein said feed-forward amplifier circuit of each of said channels comprises: a distortion detector circuit provided with a main amplifier, for detecting distortion component from the output of said main amplifier and for outputting said detected distortion component together with a main signal component from said main amplifier; and a distortion canceller circuit provided with an auxiliary amplifier that amplifies said detection distortion component, for canceling said distortion component in said main signal by said amplified distortion component; wherein said distortion detector circuit of said feed-forward amplifier circuit of said each channel comprises: a power divider for dividing the corresponding output from said input-side multi-terminal power combiner, for input to a first delay line and a main amplifier path; a first variable attenuator, a first variable phase shifter and said main amplifier interposed in series with said main amplifier path; a power divider/combiner supplied with the outputs from said main amplifier path and said first delay line, for power-dividing and combining said outputs and for outputting their sum and difference components as said main signal component and said distortion component, respectively; and wherein said distortion canceller circuit of said feed-forward amplifier circuit of said each channel comprises: a second delay line for transferring said main signal component; a distortion injecting path for transferring said distortion component; a second variable attenuator, a second variable phase shifter and said auxiliary amplifier interposed in series with said distortion injecting path; and a power combiner for power-combining the outputs from said second delay line and said distortion injecting path to thereby cancel said distortion component in said main signal component with a distortion component amplified by said auxiliary amplifier and for outputting an amplified transmission signal contained in said main signal component.