Crosscoupling reduction in multifed multimode microwave-heating cavities by means of inner doubly corrugated filters

Multimode cavities with multiple feeding ports are usually used in microwave heating processes. In this work a new approach for reducing the crosscoupling between waveguide feeds in multimode cavities is presented. This approach is based on the use of doubly corrugated reactive filters within the oven in order to divide the cavity into independent stages. The purpose of this separation is double: on the one hand microwave power sources are protected against non-desirable energy coming from other sources, and on the other hand the heating process may be improved by placing more power sources. A cavity with four waveguide feeds, placed in two different configurations, is analyzed by means of CST commercial simulation software. Results have been obtained for different materials and three different scenarios: with and without inner filter, and with only the metallic plate. A big reduction of the crosscoupling for all the analyzed scenarios is achieved.