Design and Simulation Study of Wraparound Couplers for Gyrotron Travelling Wave Amplifiers

Abstract

In this paper, the design methodology of an input coupler for X band gyrotron amplifier (gyro-amplifier) has been presented along with a comparative study of 4-slots and 5-slots variant of couplers. In addition to the 3D modelling, the RF propagation characteristics have been studied through the CST microwave studio. The two different configurations of input coupler (4-slots and 5-slots) are incorporated in X-band gyrotwystron for Particle-in-cell (PIC) simulation study. The S11 and S21 of 4-slot input coupler have been found as-25.9 dB and-0.1 dB respectively and the S11 and S21 of 5-slot input coupler have been found as-31.5 dB and-0.09 dB respectively. Further, the performance of couplers is evaluated using the 3D PIC code CST particle studio. © 2019 IEEE.