Equivalent Surface Impedance of Superconducting and Regular Strips for Moment Method Analysis of Planar Circuits

Abstract

The purpose of this communication is to present an analysis of the ac impedance of superconducting strips for any geometry by derivation of the current distribution over the strip cross section. The analysis is based on the separation of varible teg*nique and the Green's function method. The aim of this study is to obtain an accurate determination of the equivalent surface impedance of superconducting thin films, which may be employed in the simulation of superconducting or regular devices with "resistive sheet-based integral equation techniques". The surface impedance is modified by using weighting factors in order to use equivalent surface impedance concept within spectral domain approach. Typical results are presented.

CAD Modelling and Characterization of a Superconducting Planar Microwave Resonator Using Complex Conductivity Measurements

“…This equivalent surface impedance of the strip may be accurately derived from the numerical determination of the electromagnetic field within the strip with a point matching technique [61, and may be written throught the use of geometrical weighting factors kr and ki [7]:' Zseq = kr Rs + jki Xs (2) where Rs and Xs are respectively the real and imaginary parts of the classical surface impedance [8]:…”