Directional microwave heating based on time reversal quantified by information theory

Microwave heating has found extensive applications across diverse industries. However, achieving directional heating remains a significant challenge due to the complexities involved in controlling the electromagnetic field distribution. To address this issue, a novel directional heating method based on time reversal is proposed in this paper. A small signal source is placed at the heated medium to radiate electromagnetic waves. The information received by each receiving unit undergoes specialized processing before being transmitted back to the cavity. Consequently, the time reversal electromagnetic field of each receiving unit gathers at the heating material to achieve directional heating. Moreover, methods are being proposed to calculate the amount of information during time reversal using information theory. These approaches also aim to quantify the disparity in electromagnetic field distribution before and after the time reversal process. A comprehensive multi-physics model of microwave heating is established to simulate the directional heating process based on time reversal. An experimental system is also constructed to validate the proposed model, where the heating results are measured by an infrared thermal imager and a thermocouple. Finally, the effects of frequency, power and phase on the performance of directional microwave heating are analyzed.