Development of an S-band klystron with bandwidth of more than 11%

The development of an S-band klystron with bandwidth of more than 11% is introduced in this paper. At the peak power level of 800 kW, the efficiency of more than 30%, the gain of more than 40 dB, the equal-driving (constant input power across the bandwidth) relative instantaneous bandwidth of 11.2%, the average power of larger than 8.8 kW, and the power fluctuation within bandwidth of less than 1.5 dB are obtained in this klystron. The design considerations, simulation, and test results are presented and the techniques adopted to extend the bandwidth of the klystron are described.