Metamaterial-based compact zeroth-order resonant antenna

A metamaterial-based compact one-unit-cell antenna realised on a microstrip line is presented. The size of the proposed antenna is only 6 x 13.5 mm (or 0.05 x 0.13 lambda(0)) at 2.7 GHz owing to zeroth-order resonance. The design procedures with closed-form solutions are provided using transmission line theory considering radiation loss. The measured antenna bandwidth is 15 MHz and total gain is 1.22 dBi.