General electromagnetic simulation tool to predict the microwave nonlinearresponse of planar, arbitrarily-shaped HTS structures.

This work describes a simulation tool being developed at WC to predict the microwave nonlinear behavior of planar superconducting structures with very few restrictions on the geometry of the planar layout. The software is int ended to be applicable to most structures used in planar HTS circuits, incl uding line, patch, and quasi-lumped microstrip resonators. The tool combines Method of Moments (MoM) algorithms for general electromag netic simulation with Harmonic Balance algorithms to take into account the nonlinearites in the HTS material. The Method of Moments code is based on d iscretization of the Electric Field Integral Equation in Rao, Wilton and Gl isson Basis Functions. The multilayer dyadic Green's function is used with Sommerfeld integral formulation. The Harmonic Balance algorithm has been ad apted to this application where the nonlinearity is distributed and where c ompatibility with the MoM algorithm is required. Tests of the algorithm in TM010 disk resonators agree with closed-form equa tions for both the fundamental and third-order intermodulation currents. Si mulations of hairpin resonators show good qualitative agreement with previo usly published results, but it is found that a finer meshing would be neces sary to get correct quantitative results. Possible improvements are suggest ed.