Mode-free electromagnetic bandgap materials with broadside radiation as phased array antenna elements

Abstract

This paper presents a new class of electromagnetic bandgap material (EBG), which we define as the bandgap-antenna structure. It is a true EBG material, with both surface and leaky waves suppressed from the whole structure along all lateral directions, and it is also an antenna element simultaneously. The configuration has two metallization layers of sliced concentric rings between a square-shaped radiating top metal layer and a bottom ground plane. The lower rings are connected to the ground plane through vias and the patch of the top layer is fed with a probe. Eigenmode- and transmission-based full-wave modal analyses of the whole structure proved the presence of a mode-free bandgap region within which the proposed design radiates to broadside direction with 6.01 dBi gain. This structure is an ideal choice for phased array elements due to being modeless along the lateral directions while radiating to the broadside direction; phased array elements will be isolated if the proposed construction is used for array elements.