G波段500 W带状注扩展互作用速调管设计研究

Design of G-band 500 W sheet beam extended-interaction klystron

针对太赫兹频段实现高功率面临物理机制上的难题,设计了一个G波段带状注速调管,展示了基于非相对论带状电子注和扩展互作用技术所能达到的功率水平以及影响性能的物理因素。文中设计基于电压24.5 kV、电流0.6 A,1 mm×0.15 mm的椭圆电子注,以及与之相匹配的互作用系统,即横向过尺寸哑铃型多间隙谐振腔,可以实现高功率和高增益。三维PIC仿真结果显示,在考虑实际腔体损耗的情况下,能够获得超过500 W的功率,电子效率和增益分别达到3.65%和38.2 dB。研究发现,输出功率和效率的提升很大程度上受到多间隙腔模式稳定性以及电路欧姆损耗的制约;输出腔的欧姆损耗对输出功率影响尤为显著,工程设计需要特别考虑。本文的研究为高频段带状注扩展互作用器件的研发打下了良好的基础。

High power generation in terahertz frequency band is limited by physical mechanism.A G-band sheet beam extended-interaction klystron was designed to demonstrate the power level and the physical factors that affect the performance of the klystron.An elliptical electron beam with a voltage of 24.5 kV,a current of 0.6 A and the dimension of 1 mm×0.15 mm was used.To match the size of the sheet beam and obtain high efficiency and high gain,the transverse-oversized barbell type multi-gap resonant cavity was used as the interaction circuit.The 3 D PIC simulation results show that more than 500 W of power output can be obtained with the actual cavity loss considered,and the electron efficiency and gain are 3.65%and 38.2 dB respectively.It is found that the power and efficiency are largely restricted by the mode stability of the multi-gap cavity as well as the ohmic loss.The ohmic loss of the output cavity has a significant effect on the final output power which should be given special consideration in engineering design.The research in this paper has laid a good foundation for the development of high frequency sheet beam extended-interaction devices.