Efficient Analytical Prediction of the EMI Bandgap Limits of PEC-PMC Metallic Enclosures Hosting RF and Digital Circuits
A metal enclosure whose lid is covered by an array of metal pins is studied in this paper. The pins are able to realize a fictitious perfect magnetic conductor surface at the pin end, thus inhibiting cavity resonances and propagation of electromagnetic interferences in a well-defined frequency band. This paper proposes an analytical model for predicting the behavior of the cavity, and thus for estimating the bandgap limits. The method is based on the planar cavity formulation, and it analytically embeds the pin-to-bottom-wall capacitance. The obtained cavity response agrees well with the simulated models of various cavity and pin dimensions. Moreover, the method is validated experimentally based on a manufactured cavity. Although some residual errors due to the difficulties in a precise calibration are present, the experimental results validate the proposed analytical model.