Octagon Rings Antennas for Compact Dual-Polarized Aperture Array

A wideband dual-polarized aperture antenna array is presented based on elements formed by pairs of octagonal rings. The octagon ring elements are linked by capacitors and kept a defined distance from a ground plane. A broader frequency bandwidth has been achieved by placing a further layer of conductive elements above the array forming a meta-material layer. Expanded polystyrene foam is used to fill the space between the array rings and the ground, and between the elements and the meta-material layer. Capacitive coupling can be realized by interdigitating the end portions of the rings. The parametric study of the proposed structure is presented. A variety of element shapes in the same arrangement have been investigated and the scan performance are compared. The octagon rings antenna array exhibits a broad element pattern with a low cross polarization in the wide scan range. The overall structure is low cost, compact and easy to fabricate.