W波段圆电模回旋振荡管准光模式变换器的理论与设计

Theory and design of quasi-optical mode converter for W-band circularly polarized mode gyrotron oscillator

基于几何光学导出圆电模回旋振荡管准光模式变换器的理论,确定了开口辐射器、椭圆面反射镜和抛物面反射镜的具体形状,研究并设计了一个由Vlasov阶梯型开口辐射器、椭圆面反射镜和抛物面反射镜组成的W波段圆电模回旋振荡管准光模式变换器。利用矢量绕射理论分析了此模式变换器的工作机理;编写仿真程序设计和模拟了W波段TE02模回旋振荡管准光模式变换器的变换过程。结果表明,在输出窗处工作模式被转换为场型较好的高斯波束,转换效率为73.9%。

Based on the geometric optics,the theory of quasi-optical mode converter for circularly polarized mode gyrotron oscillator is derived.Also,the stepped-cut launcher,the elliptical reflector and the parabolic reflector are determined.A quasi-optical mode converter for a W-band circularly polarized mode gyrotron oscillator,consisting of a Vlasov stepped-cut launcher,an elliptical reflector and a parabolic reflector,is studied and designed.The operation principle of the converter is analyzed with vector diffraction theory,and a simulation code is developed to design and simulate the operation of converter for W-band TE02 mode gyrotron oscillator.The simulation results show that the operation mode is converted into the good Gaussian mode at the output window,and the conversion efficiency is 73.9%.