Recent Advances to Improve the Uniformity and Efficiency of Microwave Heating of Foods Using Solid-State Generators: A Review.

Advancements in semiconductor technology have remarkably increased the availability of solid-state (SS) microwave (MW) generators, facilitating their adoption in various heating applications. Compared to traditional vacuum tube systems, SS technology offers precise control over frequency, phase, and output power, enabling novel strategies aimed at improving heating efficiency and temperature uniformity. This review first examines the basics of dielectric heating and contrasts the operational differences between SS and conventional magnetron-based MW sources. It then evaluates recent studies on frequency and phase-shifting approaches, which are unique to SS systems, to enhance MW heating performance of foods. In addition, conventional methods for improving heating uniformity, such as the introduction of moving objects and modifications to the cavity, sample, and waveguide, are analyzed in the context of SS systems. The review concludes by highlighting emerging applications and identifying future research directions necessary for the broader adoption of SS technology in MW heating processes.