Demonstration of a G-Band High-Power Extended Interaction Klystron

In order to meet the high-power source requirement of compact submillimeter-wave systems, a high-power G-band extended interaction klystron (EIK) has been developed at the Aerospace Information Research Institute, Chinese Academy of Sciences (AIRCAS), and reported for the first time. The extended interaction circuit design based on over-synchronous voltage and high quality factor is proposed to enhance the output power and gain. In this manner, the designed EIK has achieved excellent test results compared with the same type of compact devices. Driven by a 20.3 kV, 198 mA pencil electron beam, the EIK can deliver a pulsed output power greater than 120 watts at around 0.22 THz, corresponding to a gain of 32 dB with a 5% duty cycle, and the average power and −1 dB bandwidth are 6 watts and 180 MHz respectively. Constrained by an axial magnetic field of about 1.03 T, the beam transmission is around 92% in RF operation.