Development of Variable Frequency Microwave Heating Setup for Foods using Solid-State Microwave System

Abstract

Objectives: The primary objective of this study was to develop and validate a variable frequency solid-state microwave (SSMW) system, which included the fabrication of dual-antenna cavity and using power-frequency control software as well as to validate system's capability to achieve dynamic impedance matching. Methodology: The experimental setup was having a solid-state microwave system (SMGM -2450MHz, Panasonic, Japan) with precise frequency control (2401 – 2482 MHz in 1MHz steps) feeding a custom-designed dual-antenna cavity (Twin Engineers, Vadodara). To validate the dynamic performance of the system, water heating experiments were run at 100 to 200W over 2 and 6 minutes. Independent variables included: sample geometry (rectangular/cylindrical), sample volume (100mL to 500mL water), and system configuration (coaxial cable type and antenna placement). Dependent variables quantified were reflection rate (3.77% to 54.93%) and power absorption efficiency (11.63% to 100%). Result and conclusions: High efficiency was critically dependent on load characteristics; the greatest variation stemmed from sample geometries and volumes. Strategic manipulation of antenna placement and coaxial cable configuration achieved optimal parameters, leading to a maximum power absorption efficiency 96.23% (reflection rate 3.77%). Conversely, poor matching efficiency dropped to 11.63%. Temperature increase (ΔT) ranged from 2°C to 26°C, correlating directly with absorbed power. This confirms that SSMW system has high potential for energy efficient processing through near-perfect impedance matching, offering a critical framework for cleaner, more consistent, and energy-minimal smart food systems.