Low cost miniature broadband linearizer

Abstract

A broadband linearizer for use with a power amplifier. The broadband linearizer includes a preamplifier, a postamplifier and a broadband linearizer bridge coupled between the preamplifier and postamplifier. The linearizer bridge comprises a power divider for coupling power to linear and nonlinear arms, and a power combiner for combining outputs of the linear and nonlinear arms. The linear arm includes a first equalizer and a delay line, and the nonlinear arm includes a distortion generator and an attenuator. A second equalizer is coupled between the power combiner and the postamplifier. A control circuit controls settings of the preamplifier, the broadband linearizer bridge, and the postamplifier. The control circuit outputs voltage bias and constant current signals to control operation of the broadband linearizer. The broadband linearizer provides for independent, flexible gain and phase control that can mate with different kinds of power amplifiers, such as travelling wave tube amplifiers and solid state power amplifiers having various gain and phase performance.