A Novel Compact Multiband Antenna Employing Dual-Band CRLH-TL for Smart Mobile Phone Application

In this letter, a novel dual zeroth-order resonance (ZOR) by using composite right- and left-handed (CRLH) metamaterial transmission lines structure is proposed for compact multiband antenna design of a smart mobile phone. The theory of ZOR and multimode technique are particularly recommended to design a compact multimode antenna covering GSM850/900 (824-960 MHz) and DCS1800/PCS1900/UTMS (1710-2170 MHz). In order to achieve a broad operation bandwidth, the proposed antenna consists of three parts that can generate two ZOR modes covering the lower band and λ/4 resonant mode covering the upper band. The simulated and measured results show that it has the performance of good radiation pattern and high efficiency, which can meet the requirement of the smart handset. The effect of each part of the proposed antenna on the performance is also analyzed, which is in agreement with the ZOR theory. In addition, the proposed antenna is also applicable to other wireless communication terminals.