Time domain hybrid method for coupling analysis of multi-conductor transmission lines on the lossy dielectric layer excited by ambient wave

Abstract

At present, numerical methods applied to the coupling analysis of transmission lines on the lossy dielectric layer excited by ambient wave are still rare in the literature. As a temptation to fill this gap, a novel time domain hybrid method is proposed, in which the modified transmission line (TL) equations, finite-difference time-domain (FDTD) method, and some interpolation schemes are organically combined together. It can overcome the difficulty in building the coupling model of ambient wave to transmission lines on the lossy dielectric layer greatly. In this method, the modified transmission line (TL) equations suitable for the coupling analysis of multi-conductor transmission lines (MTLs) on the lossy dielectric layer are derived from the traditional TL equations firstly. Compared with the traditional TL equations, the electromagnetic fields in the lossy dielectric layer are introduced into the equivalent distribution sources of modified TL equations. Generally, the precision of TL equations is dependent on the accuracy of equivalent distribution sources, which are obtained from the incident electric fields parallel and perpendicular to the MTLs. Therefore, the FDTD method is utilized to model the structure of lossy dielectric layer to calculate the electromagnetic field distribution surrounding the MTLs and in the dielectric layer. Since the heights and distances of MTLs can be arbitrary values, the electric fields parallel and perpendicular to the MTLs cannot be obtained from the electric fields on the edges of FDTD grids directly, which should be computed via some interpolation schemes. Then the modified TL equations are established, which should be solved by the central difference scheme of FDTD method to obtain the voltages and currents on the MTLs and terminal loads. The significant feature of this proposed method is that it can realize the synchronous calculations of electromagnetic field radiation and transient responses on the MTLs. Finally, numerical simulations of single and multiconductor transmission lines on the lossy dielectric layer excited by ambient wave at different incident angles are employed to exhibit the accuracy and efficiency of the proposed method by comparing with the simulation software CST. Because the structures of MTLs do not need to be meshed, the proposed method outperforms the simulation software CST in both memory usage and computation time.

A generalized simplified modeling method for electromagnetic coupling effects of uncertainty strapping cable harness

“…机电系统电磁耦合通道的等效建模是复杂电 子系统电磁兼容分析的重点与难点 [1,2] . 线缆是机 电系统电磁耦合干扰的主要传导路径, 现有文献表 明, 线缆产生的电磁干扰是大部分系统不符合电磁 兼容规范的主要原因.…”

Coupling analysis of transmission lines excited by space electromagnetic fields based on time domain hybrid method using parallel technique*

“…where 𝑉 sca (y,t) and 𝐼(y,t) are the scattered voltage vector and total current vector of MTLs, respectively; 𝐿 and 𝐶 denote the per unit length inductance and capacitance matrices of MTLs respectively, and they can be computed by the empirical formulas used in Ref. [14]; 𝑉 F (y,t) is the equivalent distribution source vector of MTLs, which can be expressed as…”

“…Unfortunately, it needs a large quantity of theoretical derivations, and the calculations of electromagnetic fields and transient responses on the loads are obtained respectively. The significant feature of FDTD-TL method [12][13][14] compared with that of FDTD-SPICE method, lies in the fact that it can realize the co-calculations of space electromagnetic fields and transient responses on TLs and loads. In this method, the space electromagnetic fields are computed by the FDTD method firstly.…”