具有渐变波导的W波段输出窗仿真与实验研究

Simulation and Experimental Studies on a W-Band Output Window with Conversion Waveguides

设计了一种具有矩形波导-圆波导渐变波导的盒型输出窗,模拟分析了其驻波比（VSWR）特性和谐振模式分布情况,研究了该输出窗的介质窗片厚度、介质窗片直径、圆波导长度和渐变波导长度结构尺寸对VSWR特性的影响规律。结果显示,介质窗片厚度对VSWR的影响最显著。热力学分析表明,当传输1 kW功率时,该输出窗的最高温度为60.6℃,最大应力仅为35 MPa。研制并实验测试了该W波段输出窗一支,结果表明,其驻波比-频率曲线分布规律与模拟结果一致,93～97GHz频带内的VSWR小于1.38,S（21）大于-0.1 dB。

An output window with two conversion waveguides was designed,fabricated,and experiment coldtested. The VSWR and the resonant modes were analyzed by changing the structure size contained the thickness and the diameter of the window disk,the length of the cylindrical waveguide,and the length of the conversion waveguide. It is showed that the most sensitive structure size for the VSWR of the window was the window disk thickness. An elaborate selection of window disk was necessary to this kind of window. With ANSYS software,we analyzed the heat dissipation and stress distribution of the window. It is indicated that the designed window could transport a microwave signal with a power of 1 k W. The experiment cold-tested results showed that the VSWR was below 1. 38 at the frequency band of 93 to 97 GHz.