Hybrid Boundary Element Method and Quasi-TEM Analysis of Two-Dimensional Transmission Lines—Generalization

Abstract

The hybrid boundary element method, based on the equivalent electrodes method and the boundary element method, is presented in this article. This method is applied on several examples for calculating the characteristic impedance of transmission lines. It should be emphasized that the combination of the equivalent electrodes method and a new variant of the boundary element method can be efficiently implemented in quasi-transverse electromagnetic analysis of transmission lines without loss of accuracy. All results for the characteristic impedance of the observed transmission lines are compared to corresponding ones obtained by the finite-element method.

Covered microstrip line with ground planes of finite width

“…A generalization of the HBEM, which is applied in this paper for microstrip lines analysis, was described in detail in [15] and [16]. This method presents a combination of the BEM/MoM, the equivalent electrodes method (EEM) [24] and the point-matching method (PMM).…”

“…The segments at any boundary surfaces between the two layers are replaced by discrete equivalent total charges. Those charges are placed in the air [15,16]. The equivalent electrodes are line charges whose radius is determined in [24].…”

“…After solving the system of equations, according to [15], it is possible to calculate the capacitance per unit length of the microstrip line, as well as the characteristic impedance and effective relative permittivity. This method will be described in detail in the following section for characteristic parameters determination of covered microstrip line with the ground planes of finite width and finite conductor thickness.…”

“…On the other side, the problem of the finite width microstrip ground plane has not been so often researched, although these forms of microstrips are typical in practice. In [4] and [14]- [15] the microstrip line with finite-width dielectric and ground plane was analyzed. A moving perfect electric wall method (MPEW) was applied in [12].…”

“…Analysis of structures with ground planes of finite width as well as finite conductor thickness is also possible using the hybrid boundary element method (HBEM) [15]. This method is applied for the microstrip characteristic parameters determination in [15] and [16]. In [17] and [18] the symmetrically coupled microstrip lines with finite and infinite width ground plane are analyzed using the HBEM.…”