Literature Review on Metamaterial

publications Review on MetamaterialLITERATURE REVIEW ON METAMATERIALThe Left-Handed Metamaterial (LHM) has a few unique properties such as disallow deviation and reversive wave. In this chapter, the basic theories behind their unique properties are presented and both(prenominal) applications of LHM toward the antenna application are discussed.DEFINITION BACKGROUND OF ham-fisted METAMATERIALElectro magnetic Metamaterial can be specify as artificial core groupive homogenous electromagnetic structures with unusual properties not readily found in nature . A Left-Handed Metamaterial (LHM) 1718or Double Negative Metamaterial (DNG) is an electromagnetic Metamaterial that exhibit prohibit permittivity and permeability. This phenomenon can be characterized by the shun refraction list and the anti- collimate phase velocity which is also known as retracted wave.HISTORY OF LEFT-HANDED METAMATERIAL (LHM)The initial work on LHM was started by V. G. Veselago from the Lebedjev Physica l Institute in capital of the Russian Federation when he made a theoretical speculation of this artificial material that exhibit negative permittivity and negative permeability. Veselago speculation remain silent for 29 geezerhood until 1996, J. B. Pendry from Imperial College London and his co-author form GEC-Marconi make a paper about artificial metallic construction which exhibit negative permittivity and negative permeability. adjacent this interesting disco truly, in 2001, the first experimental verification was made by Shelby, Smith and Schultz at the University of California. The go away handed material structure consists of split beleaguer resonator and lithe wire inspired by J. B. Pendry as shown in shape 3.1. betoken 3.1 First experimental LHM structureSince the introduction of LHM twelve years ago, many researchers were interested in investigating this artificial material and several of them was using LHM to improve the properties of the atom-bomb devices such as antennas and filters. Many papers have been published regarding the LHM integrated with antennas and their properties have been analyzed. The focusing act of LHM has made a low gain antenna becomes directive and have an increment of gain.FEATURES OF METAMATERIALImprovement in the performance of a small monopole antenna, realized via the use of an ENG envelope that compensates for its high capacitive reactance.Lens effect produced by DNG slabs that are useful for enhancing the directivities of a small antennas, e.g. dipole and Microstrip opuses, by collimating the cylindrical waves emanating from these antennas and focusing them at infinity.Creation of super lenses which can have a spatial resolution below that of the wavelength.UNIQUE PROPERTIES OF LEFT-HANDED METAMATERIALSNegative Refractive Index For conventional material with r 0 and r 0, the refractile index is given=, so that the conventional material possesses a positive refractive index. Yet, Left-handed Meta-material has both negative permittivity (r r The Snells law is described as ..3.3.1(a)W here(predicate) 2 the incident is angle and 1 is the refraction angle. Supposing fair I and medium II are conventional materials with 10 and 20 respectively, them refracted giddy will be dead set(p) with positive with the normal line OO as indicated by the 4th light ray in figure3.2. If medium II is a left-handed meta-material with 2Figure 3.2 Passage of a light ray done the boundary between medium I with positive refractive index 0 and medium II with refractive index .The phase velocity expression -= shows that the phase velocity - is related to the index of refraction , here c denotes the speed of light in a vacuum. For LHM has negative refractive index ( Figure 3.3 The zippo flow and group velocity propagate in front in LHMs but the phase velocity is backwardVeselago also predicted that the Doppler and Cerenkov effects will be reversed in LHM. An approaching source will come along to radiate a t a lower frequency and charged particles moving faster than the speed of light in the medium will radiate in a backward cone, not a forward cone. These two exotic properties are not employed in this Dissertation, however details about them can be found in.LEFT-HANDED METAMATERIAL STRUCTUREThe first LHM structure consists of split ring resonator (SRR) and thin wire (TW) or capacitance loaded strip (CLS)19. The SRR exhibits the negative value of permeability and the CLS and TW exhibit the negative value of permittivity in a certain range of frequency.Split Ring Resonator (SRR)(b)Figure 3.4 (a) broadside split ring resonator and (b) Square split ring resonatorA split ring resonator (SRR) as shown in figure3.4 is part of the LHM structure that exhibit negative value of permeability. If the excitation of the magnetic field is perpendicular to plane of the structure, this will generate the magnetic dipole moment. The SRR is a highly semiconducting structure in which the capacitance bet ween the two rings balances its inductance . The SRR induces high current engrossment structure which creates a large magnetic moment.Capacitance Loaded Strip (CLS) and Thin Wire (TW)(a) (b)Figure 3.5 (a) Capacitance loaded strip (CLS) and (b) Thin wire (TW)figure 3.5(a) shows the capacitance loaded strip (CLS) and figure 3.5(b) shows the thin wire (TW). CLS and TW would produce strong di electrical like response. As electric field propagates parallel through the TW or CLS, it will induce a current along them. This will generate an electric dipole moment to the structure and exhibit a plasmonic-type of permittivity frequency .CST SOFTWARECST was founded in 1992 byThomas Weiland. The main harvest-festival of CST is CST STUDIO SUITE,which comprises A various modules dedicated to specific application areas. There are modules for microwave RF applications, summarized in CST MICROWAVE STUDIO, low frequency (CST EM STUDIO), PCBs and packages (CST PCB STUDIO), cable harnesses (CST CABLE STUDIO), temperature and mechanical stress (CST MPHYSICS STUDIO) and for the excuse of the interaction of charged particles and electromagnetic fields (CST PARTICLE STUDIO). All modules are integrated with a agreement and circuit simulator (CST DESIGN STUDIO). The version is CST Microwave Studio 2010.Figure 3.6 CST Microwave StudioIn adjoining chapter, the design of the LHM is discussed and the procedure in the pretext of the LHM using CST software is elaborated thoroughly. Besides that, the design of the Metamaterial structures, patch Microstrip antennas are also elaborated.CST Microwave Studio is a fully featured software package for electromagnetic analysis and design in the high frequency range. It simplifies the process of inputting the structure by providing a ruling solid modeling front-end which is based on the ACIS modeling kernel. Strong graphic feedback simplifies the definition of Your device hitherto further. After the component has been modeled, a fully automati c meshing procedure (based on an expert system) is employ before the simulation engine is started. The simulators feature the Perfect Boundary Approximation (PBA manner) and its Thin Sheet technique (TST) extension, which increases the accuracy of the simulation by an order of magnitude in comparison to conventional simulators. Since no method works equally well in all application domains, the software contains four different simulation techniques (Transient solver, Frequency domain solver, Eigenmode solver, Modal analysis solver) which best fit their particular applications.The most flexible ray is the transient solver, which can obtain the entire broadband frequency behavior of the simulated device from notwithstanding one calculation run (in contrast to the frequency stepping approach of many other simulators). This solver is very efficient for most kinds of high frequency applications such as connectors, transmission lines, filters, antennas and many more.