A high-impedance surface based antenna — Lose the antenna

In this paper a high-impedance surface based antenna is designed by using only the high-impedance surface structure itself. No horizontal dipole antenna, commonly used in such antenna structures, is used at all. By utilizing two characteristic resonance modes of the surface structure, namely the plasmonic resonance and the structural high-impedance surface resonance mode, two separate resonance bands are formed. The frequency range of the modes can be determined from analytical models of high-impedance surfaces. Furthermore, we study how to excite the modes separately in order to produce orthogonal radiation patterns for a transmitting antenna. It is found that the modes can be excited without any additional matching elements with good matching levels and the resonance frequencies of the antenna follow the values estimated by the analytical models. Also, the possibilities to further improve the bandwidth of the antenna structure and the properties of the two resonance modes are discussed.