Computation of flux effects in high temperature superconducting coplanar waveguide

Abstract

We present a simulation methodology of propagation parameters and study their relationship with flux effects in a High Temperature Superconducting (HTS) Coplanar Waveguide placed in an external magnetic field. The impact of vortex dynamics on the electromagnetic signal propagation is clearly made out for a wide range of applied field, temperature and strip thickness. The vortex effects are incorporated by using a complex dynamic mobility term proposed by Coffey and Clem (CC) in their modified two-fluid theory. The dyadic Green's functions in Spectral Domain are formulated accordingly by treating the surface impedance derived from CC model as a complex resistive boundary condition. The thermal and field effects are incorporated into the analysis in a self-consistent manner using CC model. By using the Galerkin's procedure, the propagation parameters are computed using Müller root finding method. The inclusion of flux dynamics significantly alter the signal attenuation which, in turn, determines the quality factor. The signal dispersion is kept to a minimum and the relationship between flux effects and the microwave signal propagation is explored.