Patent ID: 6734726
Filing Date: 2004-05-11
Classification: H03F

Abstract:
A balanced amplifier distortion reduction circuit comprising:an input phase shifter and attenuator configured to receive an amplifier input signal and to output a phase shifter and attenuator signal; a main amplifier that includes a plurality of amplifying devices, an input splitter, and an output combiner, the splitter configured to receive the phase shifter and attenuator signal and to route a portion of the signal to each amplifying device wherein each amplifying device is configured to receive a portion of the phase shifter and attenuator signal and to output an amplified replica of the portion of the signal into the output combiner, the output combiner configured to combine the outputs of the plurality of amplifying devices and to output a main amplifier output; a sampling coupler connected to the output of a selected one of the amplifying devices, the sampling coupler configured to receive the output of the amplifying device and to extract a sample of the received output of the amplifying device; and a distortion coupler connected to an input of a second one of the amplifying devices, the distortion coupler configured to receive the respective portion of the input signal for the second amplifying device and an adjusted distortion signal, and to combine the received input and distortion signals and to output a combined signal into the input of the second amplifying device.