高频传输室过渡接头内导体的形状优化设计

Optimized Design of Transitional Inner Conductor for GTEM Cell

研制吉赫兹横电磁波传输小室，其过渡接头的结构设计尤为关键．运用电磁学中的能量对偶法精确求解GTEMcell中过渡接头部分的特性阻抗，通过建立和求解精确的过渡接头内导体侧边曲线方程，对内导体侧边形状进行优化设计．改进了以往GTEMcell过渡接头内导体侧边采取直线过渡的近似设计方法，解决了高频输入转接头的设计制作难题，保证了高频传输室的整体性能．测试结果表明：采用优化设计过渡接头内导体研制的传输室在0．4～15GHz的频带范围内，电压驻波比均小于1．5，其综合性能明显高于优化设计前的高频传输小室．

The design of high frequency input connector is especially important for the development of wide band gigahertz TEM cell （GTEM cell）. The energy method in elecnomagnetism was used to calculate the characteristic impedance of input connector. The transition section of inner conductor was optimized by establishing and solving the exact continuous curve equations of the transitional inner conductor＇s two sides. The problem of deign and manufacture of high frequency input connector was discussed and the general performance of GTEM cell was analyzed. The experiment results indicate that the VSWR of the GTEM cell with such a connector is less than 1.5 during the frequency band 0. 4 15 GHz. The comparison of VSWR shows that the performance of the optimized GTEM cell is better than the conventional one obviously.