FDTD Analysis of Microwave ovens using two or more magnetrons

The absorbed power from an object inside a microwave oven, fed by one or two waveguide, has been simulated with the Finite Difference Time Domain (FDTD) method. When n waveguides feed the oven, only a simulation can be done using n frequencies near the working frequency and evaluating the electric field on the object in a longer period. In this way the two not correlated magnetrons are simulated with the two non-orthogonal sinusoidal signals feeding the waveguides. The accuracy of the results is reported with respect to the cell size comparing the reflected and the absorbed power with the incident power.