Efficient Analytical Prediction of the Cavity Resonant Behavior of PEC-PMC Metallic Enclosures and Packages

A metal enclosure whose lid is covered by an array of metal pins is studied in this article. The pins are able to realize a fictitious perfect magnetic conductor surface at the pin end, thus inhibiting cavity resonances in a well-defined frequency band. The article 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 embeds analytically the pin to bottom plate capacitance. The obtained cavity response agrees well with the simulated models of various cavity and pins dimensions. Moreover, the method is validated experimentally based on manufactured cavities. An in-depth parametric analysis is carried out for precisely evaluating the limit of validity of the proposed cavity model based approach in the prediction of the bandgap upper and lower limits.