Low Profile Wide Band Antennas using Electromagnetic Bandgap Structures with Magneto-Dielectric Materials

In this paper, a novel application for magneto-dielectric materials is introduced. Using magneto-dielectric materials, a compact wide band electromagnetic bandgap (EBG) structure is designed. The numerical results show that this EBG has an in-phase reflection bandwidth of 70% which is several times greater than a conventional EBG resonating at the same frequency while its cell size is smaller. Using this EBG as the ground plane, a low profile unidirectional spiral antenna is designed to operate over the 8 to 18 GHz. The VSWR and gain of the designed low profile antenna is shown to be comparable to the PEC backed spiral antenna (backing at lambda/4), while achieving a 72% reduction in profile.