A design of K-band predistortion linearizer using reflective Schottky diode for satellite TWTAs

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 -5.8 dB and -37.3/spl deg/ to 0.8 dB and 6.7/spl deg/ by proposed predistortion linearizer, respectively.