Combined tank and applicator design of radio frequency heating systems

A finite-element eigenmode characterises the combined tank and applicator cavities of radio frequency heating systems. The aim is to enable a designer to specify the geometrical configurations of the combined systems for operation at the ISM (industrial, scientific or medical) frequency bands without having to build many expensive prototypes. The use of mathematical modelling results in a linear eigenvalue problem which is solved by the implicitly restarted Arnoldi method followed by spectral transformation to enhance convergence to a desired portion of the spectrum. After considering first the tank circuit in isolation: the combined tank and applicator circuits are linked and a similar eigenmode analysis shows its effectiveness in examining the various geometrical configurations in terms of tuning and the establishment of other resonances. This is the first step in tackling the problem that such industrial systems may pose as far as electromagnetic compatibility is concerned