基于拓扑网络的屏蔽腔体内置微带线响应分析

Response analysis of microstrip lines in the shielding cavity based on topological network

针对外场激励下屏蔽腔体内微带线的耦合终端响应,提出一种基于电磁拓扑网络的半解析混合算法——传输线网络BLT(Baum-Liu-Tesche)方程法.首先建立孔缝、腔体及微带线的电磁拓扑模型,然后结合腔体格林函数法,求解磁流激励腔体内的电场分布,最后利用网络BLT方程求解各节点处的电压和电流,即可得到任意位置处的微带线耦合终端响应.通过与实测值、其他方法计算结果对比,验证了所提方法的有效性.计算结果表明:在腔体和孔缝的谐振频率附近,微带线响应出现了峰值;且微带线距孔缝越近,产生的耦合电压值越大;入射脉冲宽度越窄,相同位置处的微带线耦合终端电压越大.

A semi-analytical combined method based on the topology network is presented to solve the problems of terminal responses of the microstrip line.First, electromagnetic topology model of apertures,cavity and microstrip is built.Then, the apertures can be converted to the equivalent magnetic currents,and the coupling electromagnetic field is expressed by using these magnetic currents and the Greens functions.Finally,the Baum-Liu-Tesche(BLT)equation is used to calculate the voltage and current,that is,the microstrip line coupling terminal response.The validity of the method is proved by comparing with measured results and other methods.Numerical results show that the response of microstrip line reaches its peak value near the slot and cavity resonance.Moreover,the microstrip line is nearer apertures while the pulse width is narrower and the coupling voltage of the microstrip is bigger.