Design of a novel EBG structure and its application for improving performance of a low profile antenna

Electromagnetic Band Gap (EBG) structures are defined as artificial periodic (or sometimes non-periodic) structures that exhibit unique electromagnetic features, such as frequency band gap for surface waves and in-phase reflection coefficient for incident plane waves, which makes them desirable for low-profile antenna designs. In this paper a novel compact slot-loaded EBG surface is presented and its electromagnetic properties are derived. In-phase reflection frequency of the slot-loaded EBG structure is 15.3% lower than in-phase frequency of basic structure with the same size. Also Simulations have verified that size of the slot-loaded EBG cell is reduced by 20% in comparison with a conventional structure with the same frequency response. This structure has been used as ground plane to improve radiation efficiency of a low profile dipole antenna and results in 13.68dB improvement in antenna return loss in comparison with conventional mushroom-like EBG and 33.87dB improvement in comparison with metal ground plane. It also improves the input-match frequency bandwidth of antenna significantly.