3D simulation of beam-wave interaction of rectangular helix traveling-wave tube

The large-signal beam-wave interaction of rectangular helix traveling-wave-tube(TWT) is performed using 3D particle-in-cell simulation code MAGIC. The linear tapered resistance couplers were used to reduce reflections, which may avoid modeling the actual complex input and output geometries and reduce the numbers of unused elements. The simulation results show that the simulation model is valid to compute the beam-wave interaction inside the rectangular helix TWT, and some key parameters to the interaction were analyzed. The X-band TWT is designed with the design parameters as follows: operating frequency from 8 GHz to 12 GHz, the highest output power of 480 W, bandwidth 4 GHz, and its electron efficiency reaches 11.8%．