Advanced methods to improve compactness in EBG design and utilization

Two advanced methods, slot-strip EBG design and stacked EBG utilization, are proposed in this paper. A distinctive improvement of compactness is achieved in EBG design and utilization. Using slots and stretched strips, two novel compact EBG structures are presented. The periods of the two EBG lattices are no more than 0.07 λ₀ at the desired band-gap frequency, resulting in the most compact EBG lattice ever achieved. Simulations and experimental results have verified that the area of each new structure is less than 40% of the normal mushroom-like EBG structure. Using noncoplanar structure, a stacked EBG utilization is proposed. The fabricated patch antenna integrating with the EBG structure demonstrates improvements in several characteristics of the antenna performance and has the winning feature of compactness.