Balancing field distribution in single-port input cavity of sheet beam klystron

A novel method was developed to balance the distribution of the longitudinal electric field (in the beam propagating direction) in the single-port input cavity's gap of the X-band sheet beam klystron. The original work is that a loaded waveguide is installed at the opposite side of the input cavity, so that the field can be adjusted within a certain range to achieve a uniform distribution. The newly-developed technique simplifies the driving unit, and solves the problem of the input signal asynchronism of the double-port input. The structure was optimized by means of a simulation with software package CST-Microwave Studio. The feasibility was verified with the lab-built cold test setup. The tested results show that the loaded waveguide is capable of easily adjusting the field distribution. In addition, the depth of the tuning nail and the dimension of the coupling aperture were found to strongly affect the field distribution. The experimental data agree fairly well with the simulated results.