Compact Analog Predistorter With Shape Tuning Capability Using Power-Dependent Impedance Matching Network

This brief presents a novel shape tunable reflective analog predistortion (RAPD) linearizer with a simple structure. The power-dependent impedance matching network (PIMN) based on parallel Schottky diode is applied to the RAPD linearizer to achieve the shape tuning function. Influence of the PIMN on the impedance of the nonlinear load is analyzed in detail. Two different types of shape tunable linearizers for the solid state power amplifier (SSPA) and the travelling wave tube amplifier (TWTA) are proposed and simulated. The shape tuning capability has been verified by a fabricated C-band RAPD linearizer. Good linearity improvement has been achieved for a C-band 20 W SSPA with the proposed linearizer.