CPW-Fed Multiband Monopole Antenna Loaded With DCRLH-TL Unit Cell

A coplanar waveguide (CPW)-fed multiband monopole antenna based on loading one dual composite right/left-handed (DCRLH) transmission line (TL) unit cell is presented. The antenna works at 3.22 GHz, 4.57 GHz, and 5.71 GHz. The first resonant frequency (3.22 GHz) is a little lower than the first resonance (3.38 GHz) of the corresponding conventional monopole, the second (4.42 GHz) is much lower than the second resonance (9 GHz) of the conventional monopole, and the third one achieves the zeroth-order (ZOR) resonance. Also the electromagnetic (EM) simulation results demonstrate that the proposed antenna has satisfactory omni-directional radiation patterns with reasonable gains. Finally the antenna is fabricated and measured; measurements and EM simulations are in good agreement.