Multi-objective directional microwave heating based on time reversal

Microwave heating has been widely applied in fields such as food processing and material treatment. However, achieving multi-objective directional microwave heating remains a significant challenge. To address this issue, a novel method for multi-objective directional microwave heating based on time-reversal is proposed. The transmitting units are placed at heating materials regions, utilizing the characteristics of time-reversal spatial focusing and the principle of electric field superposition to achieve multi-objective directional heating. These transmitting units radiate electromagnetic waves sequentially, while receiving units collect and process the information from the transmitting units, then send it back into the cavity, enabling multi-objective directional microwave heating. To validate the proposed method, both simulations and experiments were carried out. The heating performance was measured by infrared thermal imager and thermocouple. The results demonstrate that the method effectively achieves multi-objective directional heating. Additionally, the strategy of introducing an aluminum block inside the cavity to enrich the scattering environment and thereby improve the time reversal heating effects were also verified through simulations and experiments. Further, the effects of power and phase on heating performance were analyzed. These results confirms that the proposed method can achieve efficient directional heating through S-parameters measurements without requiring complex optimization processes. The method offers excellent portability and broad application prospects.