使用广义传输线方程建模微带电路

【作者】 杨鹏；

【导师】 喻志远；

【作者基本信息】 电子科技大学 ， 无线电物理， 2004， 硕士

【摘要】 本论文所研究的课题是香港城市大学研究基金项目“利用表面梅方法进行高性能数值计算解决应用电磁学问题”的一部分。其要求是对一种新型的传输线微分方程的存在进行数值验证,通过建模微带电路结构,提取出宽频带内可供使用的电路参数,该电路参数中的辐射系数能表示出所取样点处能量的辐射或耦合情况。首先,我们对矩量法和基于矩量法的电磁场仿真软件IE3D的基本原理进行了分析,然后对新型的广义传输线方程的存在性和唯一性从算子理论和二端口网络H参数电路矩阵两方面进行了推导。在数值验证部分,我们首先对微带线用传统的传输线方程建模,提取出电路参数L,C并和广义传输线方程提取的电路参数L,C进行比较和分析。由于所提取的电路参数在恢复电流,电压时缺少两个边界条件,所以通过插值两个电流方程实现,然而,在这样的情况下,依旧不能恢复电路结构上的电流和电压,一般的方法是采用Liu方程来弥补,这时我们确实可以恢复电流和电压,然而所提取的电路参数却发生了微小的变化,在此基础上,我们直接采用H参数矩阵求解微带线并和广义传输线方程提取的电路参数进行对比。 使用H参数建模的最大好处就是无需再通过插值来补充恢复电流电压所需的方程,并且采用H参数求解以后,广义传输线方程可以建模微带间隙结构,这样就超越了普通传输线方程的限制。由于广义传输线方程的基础是基于矩量法软件IE3D的,所以矩量法软件IE3D的准确性对提取电路参数将产生非常重要的影响,我们分析了微带结构的网格划分对电路参数的影响。最后,我们得出了如下结论,①采用广义传输线方程提取的电路参数确实可用。②基于矩量法的广义传输线方程从目前的数值仿真软件上仍然无法证明的存在,以及确切的物理含义依旧有待进一步探讨。③当频率变得非常高时,由于普通传输线方程难以建模微带结构,所以普通传输线方程还是有需要改进的地方。更多还原

【Abstract】 The dissertation is supported by the research foundation project of the City University of Hong Kong, is a part of "High-performance Computing for Applied Electromagnetic Problems by Using On-Surface Measured Equations of Invariance method", the aim is to testify the existence of a novel transmission differential equations from numerical validation, by modeling microstrip circuit structure, and exacting the applicable circuit parameters in wide frequency range, radiation efficient can represent the local energy radiation and emission at sampling point.In the first part, the Moment of Methods and software IE3D based on moment of methods are analyzed, Then we derive the novel generalized transmission line equations from arithmetic operators theory and two-port network H parameter circuit matrix.In numerical validation, we first use conventional transmission line equations to model microstrip structure, then we use Generalized transmission line equations to model microstrip structure and compare both circuit parameters ,. When using the exacted circuit parameters to restore voltage and current, considering lack of two boundary conditions, we get another two equations by extrapolating current distribution equations at the excitation and loading ports.In this way, we still can’t restore current and voltage distribution well, commonly, we use Liu equations to solve the problem, but another problem occurs, that is the exacted circuit parameters have some subtle changes, when we directly use H parameter matrix to model microstrip line to get circuit parameters and compare with those extracted by Generalized transmission line equations.The goodness of using H parameter matrix modeling is that when restoring current and voltage distribution, don’t need extrapolation equations, and Generalized transmission line equations can model microstrip gap structure, surpass the limits of the conventional transmission line equations. Due to our Generalized line equations is based on software IE3D, the precision of software IE3d will take a critical effect on our exacted circuit parameters, so the effect of mesh division is analyzed,Finally, we take the conclusion as follows 1. , circuit parameters exacted by generalized transmission line equations is applicable.2. The existence of is still unknown from the numerical validation and definite physical comprehensions need more discussion.3. When frequency is too high, due to conventional transmission line equation is <WP=6>difficult to model microstrip structure, so the conventional transmission line equations have some improvement maybe.更多还原