Preliminary research of a V-band coaxial relativistic transit-time oscillator with traveling wave output structure
Bingfang Deng, Juntao He, Junpu Ling, Lili Song, Lei Wang
Abstract
A V-band coaxial relativistic transit time oscillator is presented. Different from the traditional transit time oscillator, in order to improve the power handling capacity, we replace the traditional standing wave extractor with a traveling wave output structure. The operation characteristic of modulation cavity is also different from traditional transit time oscillators. The electron load conductance of modulation cavity is designed to be positive to reduce the maximum surface electric field. The device is investigated by particle-in-cell (PIC) simulation and preliminary experiment. In PIC simulation, an output microwave of 689 MW at 60.16 GHz is obtained with a diode voltage of 400 kV and beam current of 5.0 kA. The saturation time is 22 ns and efficiency is 34.5%. In experiment, the radiation pattern of the system is measured, and output power is calculated. A 135 MW V-band microwave at 60.20 GHz is obtained with a diode voltage of 405 kV and beam current of 5.1 kA.