Radio frequency and microwave heating: a perspective for the millennium

This article describes some developments in the simulation of radio frequency and microwave systems using numerical and circuit techniques at the Electricity Utilisation Group (EUG). The circuit techniques include network analysis and nonlinear minimisation for the estimation of component values and for the rapid impedance matching of an applicator to the tank oscillatory circuit. The applications of finite elements are carried out in the frequency or time domains using a driven or an eigenvalue approach to determine the electric field, resonant modes, complex impedance and other parameters. Finite elements are also used in the simulation of microwave applicators and their combination with the flux corrected transport method represents a powerful tool for studying the transient and steady-state behaviours of various phenomena, notably corona discharges. The use of a parallel has brought within reach solutions to problems with a million degrees of freedom or move.