Abstract

In this paper, a new predistortion method to reduce nonlinearity of a traveling wave tube amplifiers (TWTAs) is proposed. Nonlinear transfer characteristics of TWTA are analyzed using a Carrier Complex Power Series (CCPS). An inverse complex power series of a predistortion linearizer to linearize TWTA are also proposed. The inverse nonlinear distortion characteristics of predistorter can be realized with reflective structure that is composed of schottky diode and resistor-terminated transmission line. The AM-to-AM and the AM-to-PM characteristics of TWTA on K-band were improved from -5.8dB and -37.3° to 0.8dB and 6.7° by proposed predistortion linearizer, respectively.