相对论返波管模式变换器的研究

Research of mode converter for relativistic backward wave oscillator

根据相对论返波管的需求设计了一种模式变换器兼反射器。它将工作模式ＴＭ１１转换成ＴＥ１１模的同时将ＴＥ１１模反射回去，用普通的喇叭形成高斯波束发射输出。在设计方案中，它是旁壁对称正弦波纹的圆波导，变换器的中心频率为１０ＧＨｚ。数值模拟结果显示，变换器的长度为７个周期时，中心频率点转换的效率已超过了９０％，工作频带达到±０．３ＧＨｚ。

According to the requirement of relativistic backward wave oscillator, a mode converter (and also a reflector) is designed. It converts the operating TM11 mode to TE11 mode and at the same time, reflects the TE11 wave. At last, Gaussian-like HE11 mode is output by a metal horn. It is designed as a periodic cylindrically symmetric sinusoidal corrugation waveguide and operates in 10 GHz. Numerical simulations show the conversion efficiency in center frequency is over 90 percent, and the bandwidth is about ±0.3 GHz.