The state of art and trend of multi-beam klystron

The multi-beam klystron (MBK) was invented in 1944, but the first practical MBK was made in Russia at the end of the 1960's. Russia has developed many types of MBKs and applied them to practical microwave systems in the past thirty years. China began to develop MBKs at the beginning of the 1990's. Several types of MBKs have been developed and applied in practice. The state of art and main research progress on the MBK are presented in this paper. The main research work and key technical problems on MBKs are also described. The trend of MBKs for the new generation of microwave electron systems is mentioned.