Effective Propagation Properties of an Enhanced Hybrid EBG/Ferrite Ground Plane

An enhanced ultrawideband and low-profile hybrid electromagnetic bandgap (EBG)/ferrite ground plane design is presented that offers an increased bandwidth and reduced profile compared to the previously presented hybrid EBG/ferrite ground plane design. Reflectivity and phase analyses of the new hybrid ground plane design indicate an instantaneous and continuous operational bandwidth exceeding 40:1 beginning at 120 MHz. The effective complex permittivity and permeability of the hybrid ground plane, which are important for feed design considerations of certain phased array antenna systems, are also presented. Additionally, return loss and directive gain analyses of Raytheon's long slot array antenna implemented with the hybrid ground plane further verify the ability of the ground plane to provide ultrawideband unidirectional radiation characteristics for ultra- wideband bidirectional radiating antennas.