Patent ID: 6204718
Filing Date: 2001-03-20
Classification: H03F,H04B

Abstract:
An apparatus for providing predistortion to a nonlinear device along an in-line electrical path between a signal source and the nonlinear device, the apparatus comprising a shunt element electrically connected between the in-line electrical path and a ground, the shunt element being operative to generate second-order distortion as the predistortion and to generate substantially no third-order distortion, wherein:the shunt element has an adjustable resistance value and comprises a shunt impedance in series with a shunt diode;the apparatus further comprises a bias source connected to, and providing a bias current to, the shunt diode, wherein the bias source is capable of varying a magnitude of the bias current; andthe shunt impedance and the shunt diode are collectively operative to generate the second-order distortion and to generate substantially no third-order distortion when the adjustable resistance value of the shunt impedance is a first value and the magnitude of the bias current provided to the shunt diode is a first current level.