On the use of the surface impedance approach in the quasi‐tem analysis of lossy and superconducting strip lines

Abstract

In this article we propose a mixed quasi‐TEM surface‐impedance (SI) approach for the analysis of metallic losses in MMICs and of superconductivity effects in microstrip lines. Our results show that the quasi‐TEM‐SI technique is a very interesting choice to compute these effects. © 1993 John Wiley & Sons, Inc.

Calculating Radar Cross Section of Lossy Targets Using the Surface Impedance Approach

“…7(d) the results of the bistatic RCS (BRCS) of a lossy conducting strip as a function of the observation angle for different strip width. Our results are compared with those obtained using a previous method based on an analytical approximation of the surface impedance [20], and the full wave simulators HFSS and CST. These results show that the maximum of the RCS magnitude is proportional to the conducting strip width.…”

“…(14) is not trivial. To circumvent these constraints, Marqués et al have proposed an alternative approximated method making use of the surface impedance concept [20,21]. Recently, this concept has been improved in [15,16] by making use of a new calculation strategy.…”

“…The surface impedance provides the boundary condition for fields outside the conductor and accounts for the dissipation and energy stored inside the conductor. The main idea of the surface impedance approach in the study of microstrip lines with rectangular cross section, as presented in [15,20], is to replace the thick conducting strip with a zero-thickness sheet that carries an equivalent surface current density, J s . The main advantage of this technique is to avoid the solution of a wave equation for the potential vector inside the thick strip (Eq.…”

“…One of those methods is the technique proposed by [20], which has been improved recently in [15,16]. The main advantage of this technique is that it can be combined with a quasi-TEM approach to form the so-called quasi-TEM surface impedance approach.…”

“…For a convenient description of the strip edge effects, as explained and detailled in [15,20], J z is expanded in terms of Chebyshev polynomials weighted with the Maxwell edge distribution. Once the unknown coefficients of the J z expansion are computed, we can use Eq.…”