射频同轴开关热特性仿真分析

Thermal Simulation and Analysis of RF Coaxial Switch

基于Ansys Workbench建立射频同轴开关的电磁热耦合计算的3D有限元模型,由HFSS计算得到射频切换系统各部件的功率损耗,将其导入稳态热分析模型作为热源,再由相似原理计算得到射频同轴开关外表面对流散热系数,最后得到射频同轴开关各部件的温度场分布。试验验证了仿真模型的有效性。分析了信号频率、功率,导体及绝缘支撑的材料属性对同轴开关温度分布的影响,对同轴开关的优化设计提供了参考。

This paper calculated the stable temperature of RF coaxial switch through the coupling of the electromagnetic field and the temperature field. Based on Ansys Workbench,3D finite element model of RF coaxial switch was built. The power loss of the RF switching system was calculated from the RF electromagnetic field in HFSS ,then the electrical results including losses were imported into the steady state thermal analysis. According to the theory of fluid similarity, the heat transfer coefficient was calculated for different surfaces of the switch. Then the distribution of the temperature field could be calculated from the temperature model. The models were verified through numerous experiments. Meanwhile,the influence on the temperature distribution of the RF switching system caused by the frequency and power of the RF signal, material properties of the conductor and insulation support were discussed. It lays the foundation for the optimization design of the RF coaxial switch.