Dual feeding cavity resonator for efficiency enhancement in liquid heating applications

A new type of microwave resonator feeding topology is proposed to enhance the power delivered to a lossy sample for microwave heating applications. The method uses two input signals with equal phase and magnitude, instead of the usual one input. As a result, for the same total input power, the delivered power can be increased to twice the power than the case of the one input. A 2.45 GHz TM010 cylindrical cavity with dual input ports is used to heat a water sample with a total input power of 0.25 W. The efficacy of the proposed heating topology was verified by 3D electromagnetic simulation and heating measurements, including S-parameters, incident and reflected power, and thermal images. All measurement results support the increase in heating efficiency in the two port case, while using the same total amount of power as for the one port cas