Design of two stage depressed collector for high-power traveling wave tube

This paper presents a method for design a suitable two stage depressed collector of X band large duty ratio coupled-cavity traveling wave tube (CC-TWT). The axial, radial velocities and radius of 96 electron trajectories in the output potion of this TWT were simulated and analyzed by 2.5 dimensional interaction package owned by 772nd factory. A refocusing segment was designed to improve the flow of electron injection layer with the help of re-simulation of these parameters. Then a two stage depressed collector was designed with optical design, structural design and thermal analysis. Finally, a TWT was assembled for testing. The measured proportion of the current distribution in every collector electrode and the collector efficiency are close to the analytical full-band average results, which means that this analytical method is suitable for design of two stage depressed collector for high-power CC-TWT.