# Harmonic Balance Analysis-lecture notes

Harmonic Balance Analysis

Harmonic balance is a non-linear, frequency-domain, steady-state simulation. The voltage and current sources create discrete frequencies resulting in a spectrum of discrete frequencies at every node in the circuit. Linear circuit components are solely modeled in frequency domain. Non-linear components are modeled in time domain and Fourier-transformed before each solving step. The informations in this chapter are taken from [8] (chapter 3) which is a very nice and well-written publication on this topic.

The harmonic balance simulation is ideal for situations where transient simulation methods are problematic. These are:

components modeled in frequency domain, for instance (dispersive) transmission lines

circuit time constants large compared to period of simulation frequency

circuits with lots of reactive components

Harmonic balance methods, therefore, are the best choice for most microwave circuits excited with sinusoidal signals (e.g. mixers, power amplifiers).

Subsections

The Basic Concept

Going through each Step

Creating Transadmittance Matrix

Starting Values

Solution algorithm

Termination Criteria

A Symbolic HB Algorithm

Large-Signal S-Parameter Simulation

Autonomous Harmonic Balance