Removable EBG-Based Common-Mode Filter for High-Speed Signaling: Experimental Validation of Prototype Design

A new common-mode filter structure based on planar electromagnetic bandgap (EBG) technologies is designed, fabricated, and measured. It is based on a previously proposed geometry, implementing a sequence of two or more EBGs resonating at a filtering frequency; however, the new filter is placed on the top of the PCB as a standalone component, instead of being included within the PCB stack up. The filter can be easily removed and substituted by another one that is designed to filter a different frequency. The replacement design should maintain the same external size of the component as the original filter, which can be achieved by choosing the permittivity of the dielectric as well as the relationship among the EBG parameters appropriately. The electromagnetic behavior of the filter is simulated and a prototype structure is fabricated and measured. Results are compared to validate the design concept and procedure.