Modeling of microwave ovens with perforated metal walls

An applied technique is proposed for resolution of issues arising in computational modeling of microwave ovens with perforated regions of metal walls. The technique relies on replacement of perforated segments by solid metal surfaces characterized by identical electric conductivity, which is calculated using S-parameters obtained by FDTD simulation of a perforated sheet in a waveguide. This approach is employed in FDTD modeling of a particular domestic microwave oven with two perforated wall segments with circular holes of diameter 3 and 3.6 mm. The resulting simulations show that perforated regions of metal walls make a negligible impact on the frequency characteristics of the reflection coefficient and so these regions can be safely replaced in the model by solid PEC sheets.