Network Analysis on Radio Frequency Prototype Industrial Applications

AbstractNetwork Analysers provide a powerful diagnostic tool involving swept frequency techniques for the design of radio frequency applicators. Such prototype applicators have been used with a number of industrial materials to assess the feasibility of drying or heating with radio frequency power. Essentially, two aspects are considered in this paper. Firstly, with the prototype applicators not coupled to an oscillatory (tank) circuit of a radio frequency source, the resonance characteristics and Q-factors are measured leading to the establishment of the utilisation efficiency. Secondly, the interaction at lower power between the loaded applicator and the tank oscillatory circuit which is coupled to it, is considered in terms of the return loss and the impedance loci. A critical electrode separation, dc, is observed which is dependent on the material loading and at which the impedance loci and return losses of the loaded applicator and tank oscillatory circuits are identical. Such an observation may be a...