Modeling of High Temperature Superconducting Coplanar Waveguides for microwave propagation under a magnetic field

The microwave propagation through a High Temperature Superconducting (HTS) Coplanar Waveguide (CPW) exposed to a magnetic field is simulated for a wide range of temperature, applied field and transmission line geometry. The magnetic field effects of a HTS coplanar waveguide is studied using the modified two-fluid model proposed by Coffey and Clem (CC). The surface impedance of the high temperature superconducting strip is determined using the CC model. This enters as the complex valued resistive boundary condition and by using the Galerkin´s procedure, we study the propagation parameters and the unloaded Q value of the coplanar waveguide. The spectral domain dyadic Green´s functions for the transmission line are formulated by treating coplanar waveguide as a coupled slotline. The results are in tune with the vortex dynamics explored by CC model. The simulation of transmission characteristics of the coplanar waveguide in the microdimensions shows lower dispersion and attenuation. The variations in signal transmission are explained using the vortex effects.