Efficient numerical optimisation of nonlinear microwave circuits by the harmonic-balance technique coupled with electromagnetic simulation

The paper discusses the application of the space-mapping concept to the computer-aided optimisation of nonlinear microwave circuits. This method allows the linear subnetwork to be characterised by electromagnetic (EM) simulation, while the nonlinear analysis and design are based on the piecewise harmonic-balance technique. The map between the EM and the circuit model (CM) parameter spaces is defined implicitly and the search for the optimum EM topology is carried out by a norm-reducing Newton iteration.