Patent ID: 6710652
Filing Date: 2004-03-23
Classification: H03F

Abstract:
A feedforward amplifier comprising:a first power splitter for splitting an input signal into two parts; a first vector adjustor for adjusting the amplitude and phase of one output signal of said first power splitter; a main amplifier for amplifying an output signal of said first vector adjustor; a second power splitter for splitting an output signal of said main amplifier into two parts; a first delay circuit for delaying the other output signal of said first power splitter; a distortion detection power-combiner for synthesizing one output signal of said second power splitter and an output signal of said first delay circuit; a second delay circuit for delaying the other output signal of said second power splitter; a second vector adjustor for adjusting the amplitude and phase of the output signal of said distortion detection power-combiner; an error amplifier for amplifying the output signal of said second vector adjustor; a distortion suppression power-combiner for synthesizing the output signal of said second delay circuit and the output signal of said error amplifier; control means of at least stopping the operation of said error amplifier or said main amplifier depending on a predetermined condition; first signal level detection means of detecting a first signal level that is the signal level of said input signal, or the signal level of a baseband signal in a baseband signal generating portion, or the signal level of a transmitting signal in a transmitting circuit, or the signal level of a received signal in a receiving circuit; and second signal level detection means of detecting a second signal level that is the signal level of said output signal, wherein said predetermined condition represents gain of said second signal level to said first signal level, and when said gain is out of a predetermined value, said control means stops the operation of said main amplifier.