Derivation of power amplifier predistortion circuits by frequency to signal amplitude transformation

In this paper, an original approach for predistortion circuit design based on the passive RC network that can realize gain expansion and phase compression is proposed. The method utilizes FET devices as the nonlinear resistor to realize the required predistortion function and is used to linearize a millimeter-wave power amplifier. This method can effectively improve the linearity while affecting other metrics only slightly. A millimeter-wave power amplifier for LMDS application was linearized with this method and comparison shows that IMD3 was improved by about 8.6 dB.