An analog predistortion integrated circuit for linearizing power amplifiers

An analog polynomial distortion circuit is designed for linearizing the response of power amplifiers. The circuit implements a fifth order complex-valued polynomial distortion function that can be used to cancel the intermodulation products created in a non-linear power amplifier. The distortion circuit has a bandwidth of 150 MHz and a modulation bandwidth of 40 MHz. It is intended for baseband or IF applications. Measured results for a class A amplifier show 10 to 30 dB reduction in IM sidebands.