Dual Band Metamaterial Inverted-L Antenna

Abstract

A coplanar waveguide (CPW) planar inverted-L antenna (PILA) is proposed. It uses a Composite Right/Left Handed (CRLH) transmisssion line metamaterial loading in order to achieve a dual band operation. It is shown that this unit cell produces a new resonant mode at 1.8 GHz plus the folded monopole mode at 3.5 GHz. The associated −10 dB bandwidth fractions around each of these frequencies are 9.2% and 22.9%, while the corresponding peak gains and radiation efficiencies are −2.6 dBi (51.64%) and 2.59 dBi (93.8%), respectively. The radiator has a total size of $55\times 54.5\times 1.6\ \text{mm}^{3}$ or $0.33\lambda\times 0.32\lambda\times 0.009\lambda$ at 1.8 GHz.