Harmonic balance algorithms for the nonlinear simulation of HTS devices

This paper describes the application of Harmonic Balance algorithms to pred ict nonlinear effects in planar High Temperature Superconductors (HTS) micr owave circuits. The resulting algorithms are fast and efficient and can be used both for the characterization of the nonlinearities in the HTS materia l, and for the prediction of the behavior of an HTS circuit given the param eters of these nonlinearities (such as a dependence of the surface impedanc e on the current density). Most previously published nonlinear HTS models c an be used, because the algorithms are not restricted to a specific model o f HTS nonlinearities. Two different types of algorithms are described: (1) algorithms specific for one-dimensional resonators (transmission lines and TM010 disk resonators) and (2) an algorithm based on the combination of Met hod of Moments and Harmonic Balance, applicable to 2D planar structures wit h few restrictions in their shape. Several cross-checks with theory and mea surements are presented.