Design of small planar antennas based on double-layered CRLH metamaterials

Abstract

This letter presents the design of a new efficient double negative metamaterial antennas. The design of the unit cell of these antennas is based on the composite right/left-handed (CRLH) transmission line model. The zeroth-order resonance of this kind of antennas depends mainly on the equivalent circuit of the unit cell and provides the opportunity to design the antenna with very small electrical size. The previous published results show that the conventional CRLH mushroom radiator suffers from narrow bandwidth and low gain. In this letter, we introduce a new method of design of CRLH metamaterial antennas to tackle the above problem using two layers of CRLH mushroom structure. The upper layer of the CRLH is used to reduce the reactance of the small antenna and to improve the matching between the antenna and the feeding line. The results at the zeroth-order resonance show improvements in the antenna gain and bandwidth by introducing the upper layer. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2224–2229, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27078