Design Optimization of Two Input Multimode Applicator for Efficient Microwave Heating

This paper presents a novel design, modeling and optimization of two input multimode applicator at 2.45 GHz for efficient microwave heating of materials. CST Microwave Studio 2012? commercial software is used to model a two input multimode applicator for coupling two low power sources to applicator chamber. Feeding microwave power at more than one location to a multimode applicator can result in improvement of field uniformity and the increase in heating power provided coupling is proper and polarization is chosen correctly. The model is simulated for different arrangements of waveguide ports and applicator is optimized to obtain low coupling between the input ports and uniform field distribution inside the applicator chamber. Minimum port to port coupling of -52 dB is achieved with two input ports arranged on adjacent face and in crosscurrent configuration. The electric field distribution in the empty cavity and cavity loaded with the wood sample is well uniform. Energy density and power loss density graphs show consistent microwave absorption inside the sample. Simulated results indicate that the microwave applicator design with this waveguide port arrangement is optimum for low port to port coupling and uniform microwave power absorption.