Patent ID: 6940346

Claim:
A feedforward amplifier comprising: a first power divider that divides an input signal into two portions; a first vector adjustor that adjusts the amplitude and phase of one portion of the output signal of said first power divider; a pre-distortion compensation circuit connected to said first vector adjustor; a main amplifier to amplify the output signal of said pre-distortion compensation circuit; a second power divider that divides the output signal of said main amplifier into two portions; a first delay circuit that delays the other portion of the output signal of said first power divider; a distortion detection power combiner that combines the one portion of the output signal of said second power divider and the output signal of said first delay circuit; a second delay circuit that delays the other portion of the output signal of said second power divider; a second vector adjustor that adjusts the amplitude and phase of the output signal of said distortion detection combiner; an auxiliary amplifier that amplifies the output signal of said second vector adjustor; and a distortion elimination power combiner that combines the output signal of said second delay circuit and the output signal of said auxiliary amplifier, wherein said second vector adjustor is adjusted so that (1) suppression is performed on only the distortion component generated within a predetermined frequency range out of the range of frequencies to be suppressed in which distortion components to be suppressed occur or (2) the suppression of the distortion component generated within said predetermined frequency range is greater than the suppression of the distortion component generated within the frequency range other than said predetermined frequency range out of said range of frequencies to be suppressed, and said pre-distortion compensation circuit is adjusted so that suppression is performed on at least the distortion component generated within the frequency range other than said predetermined frequency range.