Decision criterion based on sensitivity analysis to solve microwave heating in a single-mode cavity

This study presents advances in microwave heating simulations in a single-mode rectangular cavity via numerical method. The main contribution of this work is to propose a new decision criterion that provides the instant when the electric field must be recalculated when solving the thermal-electromagnetic problem inside the cavity. In most cases, the decision criteria found in the literature are empirically based on the variation of the loss factor. In this work, it is shown that the authors may introduce significant errors in the results and/or increase the simulation time. Here, the decision criterion is based on sensitivity analysis techniques that evaluate the derivative of the electric field with respect to the complex permittivity. Numerical results show that the new decision criterion works well for different load conditions and can be easily implemented with a hybrid analytical-finite element method.