In this paper is presented a resonant type wire antenna of the compact size, it was implemented using a compo site right/left-handed transmission line. The array of three antennas can be used as isotropic sensor. It was built with the junction of three cells that presented resonant frequency in the mode zeroth-order (infinite wavelength).
Keywords-Metamaterials; composite right/left-handed (CRLH); Compact antenna; resonant antenna; Isotropic sensor. I. INTROD UCTION With the discovery and development of composite right/left-handed transmission line (CRLH TL) theory many researchers have been guided to develop novel types of microwave devices using this property [1]-[6] and [12]. A number of RF/microwav e practical component, antenna and system applications, based on the concept of CRLH metamaterials have already been demonstrated to exhibit unprecedented perform ances and functionaliti es [2]. The effect of the metamaterial transmission line (TL) is an extraordinary consequence of the permittivity and permeability. The CRLH TL has the unique property of an infinite-wavelength wave at specific non-zero frequency because of the zero permittivity and perme ability [1], [2] and [3]. The CRLH concept takes into account and exploits the dual nature of real Left-Handed (LH)structures, which also include natural Right-Handed (RH) contributions. At low frequencies the RH effects are weak and propagation is essenti ally LH, leading to backward wave propagation, whereas they become dominant at higher frequencies, leading to forward wave propagation [4]. The LH metamaterial and the CRLH metamaterials were proposed and applied for enhan cing antenna designs; they are basically the dual of traditional transmission lines. The recognition of this dual nature of metamaterials and the developm ent of advanced analysis has paved the way for a novel generation of microwave components including antennas. Metamaterials have increasingly attracted researchers' attention because of its unique electromagnetic properti es. It has been proven that metamaterials can be applied to antenna application where the size of the antenna is substantially reduced [5].In this paper, we employ the metamaterials effects and characteristics to create a resonant type wire antenna of the compact size where the resonant frequency in the mode zerothorder (infinite wavelength) is independent of the physical length, so that the resonator can be arbitrarily of smalI length [6].CAPES and CNPq , Brazilian government agenc ies 978-1-4244-5357-3/09/$26.00©2009IEEE