Using the 2D-FDTD method for the accurate analysis of superconducting coplanar waveguides and the design of planar rectangular inductors

The accurate analysis of superconducting passive microwave components requires an exact modelling of the material properties due to the strong kinetic inductance effects in high temperature superconductors. It will be shown that the 2D FDTD method based on Maxwell's equations extended by the London Theory is an adequate method to analyse superconducting coplanar waveguides. The stability condition for the FDTD simulation of superconducting material will be analysed by investigating the Z-transform of the FDTD update equations and taking advantage of its similarity to a digital IIR filter. Additionally, a method combining 2D-FDTD and quasistatic FDM simulation results for the design of passive lumped element components will be introduced. The simulation and the measured results for a planar rectangular inductor in a coplanar environment have been compared and show good agreement.