Design of elliptical electromagnetic bandgap structures for directive antennas

This paper presents the design of directive antennas for wireless communication systems by incorporating elliptical electromagnetic bandgap (EEBG) materials composed of metallic wires. These structures have an elliptical shape and are radially periodic, and they are excited at their center using a monopole antenna. Defects were introduced and designed in the EEBG structure to open electromagnetic localized modes inside its frequency bandgap, and then to create a directive beam. An antenna prototype, operating at digital communication services (DCS), personal communication services (PCS), and universal mobile telecommunications systems (UMTS) bands, was designed, fabricated, and tested. A good agreement is obtained between simulated and experimental results for both return loss and radiation patterns.