Planar Dual-Band Omni-Directional UHF Antennas Employing a Composite Right/Left-Handed Double-Sided Metal Layer Structure

摘要

This article presents planar dual-band omni-directional antennas employing a composite right/left-handed (CRLH) metamaterial for UHF applications. The antennas are compact and in a simple double-sided planar configuration without using vias or lumped-elements and have an omni-directional radiation pattern regardless of having a ground plane at the backside. A dual-band antenna operating at a pair of the negative (f_(-1)) and positive (f_(+1)) resonant frequencies is designed at 373/817MHz and the dual-band operation with omni-directional radiation patterns are demonstrated. The physical size of the presented antenna is λ_(-1)/13×λ_(-1)/18×λ_(-1)/1005 at f_(-1), and λ_(+1)/8×λ_(+1)/6× λ_(+1)/459 at f_(+1), where λ_(-1) and λ_(+1) are free space wavelengths at f_(-1) and f_(+1), respectively. Maximum measured gains at f_(-1) and f_(+1) are -13.8dBi and -0.5dBi, respectively.