Development of a C-Band 2.5-MW Peak Power Broadband Klystron Based on High Efficiency

This paper presents the design considerations, simulation results, and test results of a high-efficiency high-power broadband klystron. In the design of the entire tube, it is the key part to design the high-efficiency beam-wave interaction section, so this part is described in detail, including the frequencies, Q values, arrangement locations of buncher cavities, as well as transit angles of drift tubes, and so on. Meanwhile, the electron gun is designed as a typical Pierce type with a pencil beam, and the perveance and normalized radius of electron beam are set to 2.1 μP and 0.51, respectively, by considering requirements of the efficiency and bandwidth synthetically. What is more, the output window is designed based on high average power by symmetric pillbox window structure. The test results indicate that in the case of saturated drive and 5.1% relative bandwidth, the klystron can get a peak power of more than 2.5 MW, an efficiency of more than 40%, a gain of more than 49 dB, an average power of more than 2.5 kW, and output power flatness of less than 0.63 dB.