Loading an Active Frequency Selective Surface in Microwave Cavities to Enhance Heating Uniformity

This letter introduces an effective method to enhance microwave heating uniformity by equipping an active frequency selective surface (AFSS) working at 2.45 GHz within microwave cavities. By changing the on/off states of p-i-n diodes embedded at different locations on the AFSS, the proposed method achieves the redistribution of the electric field in the microwave cavity. Simulations demonstrate an increase of over 36% in heating uniformity across different heated samples through diode state control. To validate this method, a microwave heating system is customized to conduct temperature measurements. Good agreement is achieved between simulations and experiments, verifying the validity of this method.