吉赫兹横电磁波传输室连接头的优化设计  

Optimal Design of GTEM Cell Connector

作　　者：张凯[1,2] 李万莉[1] 于得水[1] 游张平[1] 

机构地区：[1]同济大学机械工程学院,上海201804 [2]常熟理工学院机械工程学院,江苏常熟215500

出　　处：《科技导报》2009年第19期33-37,共5页Science & Technology Review

基　　金："十一五"国家科技支撑计划项目(2006BAJ12B01)

摘　　要：吉赫兹横电磁波(GTEM)传输室在电磁兼容测试领域应用广泛。GTEM传输室过渡连接头对GTEM传输室性能的影响较大。过渡连接头连接同轴传输线与GTEM传输室主体,是从圆形同轴传输线过渡到矩形同轴线的转换部件。如果过渡连接头处存在结构不连续,使其特性阻抗与GTEM传输室不匹配,将会引起电磁波反射和激发高次模现象,降低传输室的传输性能。根据GTEM传输室的技术要求,以传输系统阻抗连续为原则,对过渡接头内导体外表面和外导体内表面的形状进行同时设计,使内导体外表面与外导体内表面光滑过渡,过渡接头的特性阻抗与系统匹配。对前后端分别与标准同轴线和斧形件相连接部位进行结合设计,保证连接表面光滑,尽量降低突变。根据设计计算数据,通过设计软件SolidWorks对过渡接头构造精确三维模型。将三维模型导入电磁软件HFSS进行仿真测试。这样,对保证过渡接头特性阻抗恒定提供了一种有效的设计方法;可以将构建的数学模型直接导入电磁仿真软件,以便进一步分析;也可以将内、外导体三维结构数模导入数控机床加工,保证内外导体表面的精度要求。Gigahertz Transverse Electro Magnetic （GTEM） transmission cell is widely used in the field of electromagnetic compatibility tests. The transition connector of GTEM transmission cell is closely related with the performance of the transmission cell. The transition connector as a transition of the conversion component between the circular coaxial transmission line and the rectangular coaxial line connects the coaxial transmission line and the main body of the GTEM transfer chamber. If there is a structural discontinuity at the transition connector, it would make the characteristic impedance and the transmission cell mismatch and cause the phenomenon of electromagnetic wave reflection and high-order modes, deteriorating the transmission performance of the transmission room. According to the technical requirements of GTEM transmission cell, it should in principle be a continuous transmission system of impedance. To design the shape of the transition joint＇s outer surface of the inner conductor and the inner surface of the outer conductor simultaneously, the outer surface of the inner conductor and the outer conductor of the inner surface could smoothly transit, and the transition joint＇s characteristic impedance could match with the system. To design the connected parts between two ends and standard coaxial line and ax-shaped pieces, the smoothly connected surface, with minimized mutations should be ensured. According to the designed calculation data, the precise three-dimensional model is constructed through the SolidWorks. Three-dimensional model is imported into HFSS to be simulated and tested. So, it provides an effective design method to ensure the constancy of impedance characteristics of the transition joints. The mathematical model could be imported directly into the electromagnetic simulation software for easier further analysis. The inside and outside of the conductor three-dimensional structure model could be imported into CNC to ensure the accuracy of conductor surface on both sides.

关 键 词：过渡连接头 特性阻抗 形状设计 吉赫兹横电磁波 

分 类 号：TN03[电子电信—物理电子学]