Development of the Radiofrequency Section of a Ku-band Multiple-Beam Klystron

ABSTRACTThe multiple-beam klystrons (MBKs) are well known for some distinct performance advantages over their single-beam versions. The advantages of the MBKs include higher average power, relatively lower operating voltages, higher bandwidth, and low individual beam current. However, the design of the MBKs is more extensive and requires thorough and careful three-dimensional electromagnetic simulations and analysis. In this article, design of a four-beam klystron compatible with a predesigned electron gun is reported. Starting with simple analytical approach, detailed design and electromagnetic simulation results of the radiofrequency (RF) cavities are presented. Uniformity of the RF coupling between the external circuitry and the cavity RF field has been investigated in detail with the help of commercially available three-dimensional electromagnetic design code. A cold-test model of the RF cavity has been fabricated and its resonant frequency has been characterized experimentally. Design of the individu...