Study on High-Frequency System of S-Band Multi-Beam Klystron

The high-frequency system of S-band multi-beam klystron is explored. The structure of the resonator is studied and its high-frequency characteristics are analyzed. The model is established by using three-dimensional electromagnetic software. With the condition of 16 kV voltage, 25 A current, 0.13 $T$ magnet, and 1 W input power, it can be obtained that the output peak power is more than 120 kW by calculation of the Particle-in-Cell (PIC) solver. The output signal is clean and free of interference, featuring a single peak at 3.25 GHz. The output spectrum is also devoid of parasitic oscillations, confirming the stable operation of the klystron's high-frequency system.