High gain dual-band open-ended metamaterial antenna utilizing CRR with broadside radiation characteristics based on left-handed AMC and PEC

This paper describes a zeroth-order resonating (ZOR) open-ended metamaterial (MTM) antenna with dual-band features with improved gain and broadside radiation characteristics. This new MTM antenna implemented using closed ring resonator (CRR) as shunt element is examined. The novelty of the design is the use of artificial magnetic conductor (AMC) and perfect electric conductor (PEC) reflector below the dual-band MTM antenna to enhance gain and also enhance radiation performance. The concern of low gain is rectified using left-handed AMC having reflection phase -90 degrees to +90 degrees from 2.31 GHz to 2.4 GHz. The same reflector provides around 180 degrees reflection phase from 3.4 GHz to 3.72 GHz, thus acting as PEC. The design principle is based on the placement of AMC at a distance less than lambda(0)/4 and PEC at distance of lambda(0)/4 below MTM antenna. The antenna gives directive radiation pattern with 3.78 dBi and 5.48 dBi increase in gain resulting in maximum gain (with radiation efficiency %) of 5.5 dBi (71.3%) and 7.1 dBi (89%) at 2.34 GHz and 3.52 GHz respectively. It provides an electrical size of radiator as low as 0.15 lambda(0) x 0.23 lambda(0) x 0.013 lambda(0) and overall volume 0.42 lambda(0) x 0.42 lambda(0) x 0.174 lambda(0). The antennas are fabricated and the simulated results are verified through measurement making them suitable for LTE (2.3 GHz-2.4 GHz), WiMAX (3.4 GHz-3.8 GHz) and WLAN/WiFi applications.