Solid-state microwave phase control for improved heating patterns in single-mode cavities

Phase control is a unique feature of solid-state microwave generators. This study investigated how solid-state phase affected microwave fields and heating patterns of foods in a 915 MHz single-mode cavity of Microwave-Assisted Pasteurization System (MAPS). A 3D computer simulation model was developed and experimentally validated using a chemical marker method. Results showed that adjusting the phase differences between the top and bottom microwave entry ports shifted electric fields patterns and moved hot and cold zones vertically along the depth of food packages. Simulations also demonstrated that phase control can align high microwave energy zones with the central layers of food packages of varying thicknesses. This would otherwise require physical conveyor adjustments in commercial microwave systems. The study provides the first experimental validation of solid-state phase control in a 915 MHz single-mode cavity and establishes a modeling framework for dynamic phase control in industrial microwave processing.