Analyzing nonlinear circuits using a modified harmonic balance method

Abstract

In recent years, the necessity for fast, accurate and less memory-intensive techniques to analyze nonlinear circuits has grown as technology has advanced. The harmonic balance (HB) method is a powerful tool and it has been used for some time in nonlinear circuit analysis. In order to keep up with the vast requirements of circuit design, the harmonic balance method is modified to make it fast, more accurate and require less memory. In the modified harmonic balance (MHB) method, circuits are analyzed by calculating voltages and currents of nonlinear components in the time domain and those of linear components in the frequency domain. After that, an iteration scheme is performed in which the voltage and current values have to be transformed from one domain to the other for each single iteration. A key point to reduce the analysis time and minimize the memory required is to use an efficient way to transform from one domain to another. One-dimensional Fourier transformations are used to convert from the time domain to the frequency domain and visa versa. The current and voltage values are handled using a vector matrix for each nonlinear element instead of using Jacobian matrices.