Numerical technique for nonlinear circuit analysis using the method of electromagnetic topology based on harmonic balance

The purpose of this study is to propose an improved numerical technique for large and nonlinear circuit analysis using electromagnetic topology based on harmonic balance. Harmonic balance has been used for the analysis of a nonlinear system; however, it needs a large number of variables that must be optimized, and this makes the method impractical for large systems. Electromagnetic topology is proper for a large system using volume decomposition; the method has been studied for linear analysis [Park, Y.-M., Y. Lee, Y.-S. Chung, C. Cheon, H.-K. Jung, 2009. Electromagnetic field penetration analysis of a rectangular aperture-backed cavity based on combination of electromagnetic topology and mode matching. Electromagnetics 29:447-462], but the method for a nonlinear system has never been studied. Therefore, a technique for combining electromagnetic topology and harmonic balance to analyze large and nonlinear systems is proposed. In the proposed method, electromagnetic topology and harmonic balance communicate in real time; the updated voltage through harmonic balance are applied to electromagnetic topology as boundary conditions, and the results of the electromagnetic topology are used for computing linear currents in the harmonic balance until errors are negligibly small. Compared with conventional methods for analyzing large and nonlinear systems, the merits of the proposed method are fast computation time, reduced memory requirements, and compatibility with other simulation and experiment techniques. A voltage doubler model was analyzed using the proposed method at 100 and 230 MHz. The results of the analysis are compared with experimental results, and the validity of the method was confirmed.