Algorithms for Software Tools with Harmonic Balance Method

The harmonic balance (HB) method is a very popular in software tools for simulation of radio-frequency (RF) circuits. In the yearly published papers, we have proposed the new method for solving HB equations. This method replaces the solution a large system of HB equations by two subsystems with very small dimensions, the solution of which is performed sequentially. In the first subsystem of equations, the number of harmonics is reduced to a certain minimum value (R), taking into account all the nodes of the circuit. In the second subsystem of equations, the number of circuit nodes is reduced to the value R, taking into account all harmonics. Previously unpublished relations and algorithms for solving equations by the Newton method are presented. The relations for calculating the Jacobian for both equations and the features of their implementation in the software are given. All algorithms are implemented in the circuit modeling software in the Matlab/Simulink system.