W波段半矩形环螺旋线行波管热分析OA

To address the thermal problems of the W-band half rectangular-ring helix travelling wave tube under high power operation,a three-dimensional model containing the slow-wave structure,dielectric substrate and metal tube shell is established using the ANSYS Workbench simulation platform,and its travelling wave tube thermal distribution characteristics and thermal deformation laws are systematically investigated.Based on the HFSS electromagnetic simulation software,a high-frequency study is carried out on the slow-wave structure of the half rectangular-ring helix,and the particle-cell simulation method of CST software is used to obtain the metal loss value of the travelling-wave tube as 6.2 W,and the body current loss of the electron injection interception as 0.9 W.Thermal simulation of the half rectangular-ring helix travelling-wave tube is carried out by the Workbench software under the effect of the total heat flow of 7.1 W.The characteristics of the significant temperature increase in the end region caused by the nonlinear distribution of heat flow are analyzed,and the thermal deformation law is also investigated.The nonlinear distribution of the heat flow leads to a significant temperature increase in the end region,and the highest temperature of the travelling wave tube reaches 161.19℃.Further analysis shows that the maximum temperature can be reduced by 13.84℃by using a beryllium oxide substrate,and the maximum temperature of the travelling wave tube is only 85.27℃if there is no contact thermal resistance between the oxygen-free copper material and the boron nitride substrate.Thermal deformation simulation shows that the maximum thermal deformation at the end of the slow wave line reaches 0.004 5 mm,and the results provide a theoretical basis for the thermal design,material selection and reliability improvement of the millimeter-wave travelling wave tube.