Figure 1. Types of Metamaterials
The main objective behind this paper is to give a brief idea on Metamaterials. In this paper, history of metamaterials, its Introduction, classification, various properties, advantages, and applications are reviewed. In this paper, different methods of parameter extraction for metamaterial structure were also examined. Metamaterials are artificially invented materials. The property of metamaterials is different from the natural materials. By using Split Ring Resonators (SRR) and Wire structure, metamaterials provide the simultaneous negative value of permittivity and permeability; same properties can also be obtained by creating different shapes on patch, e.g. Coupled pi shape, Omega shape, Complementary Split Ring Resonator (CSRR), etc. Compared to conventional materials metamaterials differ in terms of their structure. In the conventional natural material we get the Positive Index of Refraction (PIR) or Right Handed Materials (RHM), while metamaterial provides Negative Index of Refraction (NIR) or Left Handed Materials (LHM). In this paper, different methods of designing and simulation of Metamaterial Unit cell and steps for the metamaterial parameter extraction were also examined.
Metamaterials are artificially constructed materials and it is not readily available in nature. In optics, interaction between light and medium gives electrical and magnetic responses and it can be represented by using materials’ permittivity and permeability. Metamaterial provides simultaneously negative value of permittivity and permeability (Mendhe and Kosta, 2011). ‘Meta’ is a Greek word which stands for “beyond”, “above”, or “Superior”. Metamaterials provide the electromagnetic property beyond the naturally available material. Electromagnetic field can be determined by the material properties, such as material permittivity (e) and material permeability (μ) (Singh and Marwaha, 2015).
In natural materials, most probably we get the positive value of materials’ permittivity and permeability, but it can be changed by using few methods. Metamaterials gain their property from structure rather than material composition (Buriak and Zhurba, 2016) by changing,
Metamaterials provide Negative index of refraction and it also obeys the Left handed rules, hence it is some time refered as a Left Handed Media or Left Handed Material (LHM) (Khushboo and Kiran, 2016).
Left handed metamaterials are not available in the nature, so LH property can be obtained by modifying its structure. The direction of the Phase velocity and Group Velocity in metamaterial is antiparallel. The metamaterial is widely used in the following areas (Uddin et al., 2016).
Metamaterials are widely used in metasurface antenna technology. Metasurface is an array of the metamaterial Unitcell. Metamaterial Surface Antenna Technology (MSA-T) is a new technology for RF antenna beam steering rapidly and precisely over wide range of the angle, and it does not require any mechanical moving parts and it does not require any phase shifter (Stevenson et al., 2016).
Such antenna is widely used for the following applications.
The main disadvantages of the mechanical and phased array antenna are heavy and also large; this problem can be solved by using MSA-T and it provides the following advantages (Stevenson et al., 2016).
To understand basic concept behind the Negative refractive index, it is first required to understand Permittivity and Permeability. Drude Model and Lorentz Model are very helpful to understand Negative Refractive Index. Out of these two models, Drude model is used for small frequency or frequency below Resonance and to understand why permittivity gets Negative in Metamaterial. Lorentz model is used for resonance frequency and it is used to demonstrate why we get Negative permeability. Negative Refractive index occurred because of the change or flips in the polarization from in phase to out phase (Pendry and Smith, 2004) .
In 1898, Jagdish Chandra Bose first stated the possibility of artificial material or Metamaterial by conducting the Microwave Experiment. In 1968, the Russian Physicist Victor G. Veselago said that materials with both negative permittivity and negative permeability are theoretically possible. In 1996, John B. Pendry identified a practical way to make Left-handed Metamaterials (LHM) which did not follow the conventional right hand rule. He proposed his design of periodically arranged Thin-Wire (TW) structure that depicts the negative value of effective permittivity. In 1999, the same group of J. B. Pendry practically demonstrate negative permeability in 1999 by using SRR structure. In 2000, Dr. Smith demonstrated Negative refractive index which gave the simultaneous negative value of permittivity and permeability by combining SRR and Wirestructure in a single unit cell ( Mendhe and Kosta, 2011; Singh and Marwaha, 2015 ; Buriak and Zhurba, 2016; Khushboo and Kiran, 2016; Kumar et al., 2016; Uddin et al., 2016; Stevenson et al., 2016; Pendry and Smith, 2004; Manohar et al., 2015; Ji and Varadan, 2016).
The different types of Metamaterials are shown in Figure 1. Based on the materials’ properties, such as permittivity and permeability, metamaterials can be divided into the following four categories.
Figure 1. Types of Metamaterials
If a material has permittivity and permeability less than zero (e< 0, μ< 0), it is termed as double negative (DNG) material. This class of materials can only be produced artificially (Manohar et al., 2015). Double negative materials can be obtained by considering various shapes like S-shape, and Omega shape, U-Shape. Following three approaches are widely used for producing DNG material (Buriak and Zhurba, 2016).
This approach is used for artificial non-resonating type structure.
This approach is given by Dr. Smith and it is based on the resonant phenomena of the metamaterial Unit cell.
This approach has a property to operate as left handed and right handed based on the frequency applied.
Double positive material is a material which has both permittivity and permeability greater than zero (e> 0, μ> 0). Most occurring media (e.g. dielectrics) fall under this category. In Double positive material, wave is propagated in the forward direction (Singh and Marwaha, 2015).
If a material has a permittivity greater than zero and permeability less than zero (e> 0, μ < 0) it is called Mu Negative (MNG) material. In certain frequency regimes, some Gyrotropic material exhibits these characteristics. In MNG material, parameters like permittivity, permeability, and refractive index will change with change in frequency (Mendhe and Kosta, 2011).
If a material has permittivity less than zero and permeability greater than zero (e < 0, μ >0) it is called Epsilon Negative (ENG) material. In certain frequency regimes, many plasmas exhibit these characteristics. It is possible to create a double negative material by combining the Mu negative and Epsilon negative material (Mendhe and Kosta, 2011).
The classification of Metamaterials is shown in Figure 2. The detailed description of the different classes of metamaterial seen in Figure 2 are as follows.
Figure 2. Classifications of Metamaterials
Electromagnetic Metamaterial affects the Electromagnetic (EM) waves because its structure is smaller than the wavelength of the EM wave. It is also called as low profile Metamaterials. It is widely used in microwave applications, such as in Bandpass filter, Radomes, Beam steering applications, lenses, etc.
Electromagnetic Metamaterials can be further classified into various types as shown in Figure 3. Detailed description of different classes of Electromagnetic metamaterial seen in Figure 3 are given below. For detailed idea about DNG and DPS metamaterial, Figure 1 can be refered.
Figure 3. Classifications of Electromagnetic Metamaterials
One of the most important properties of metamaterial is Negative Refractive Index, such property is found in Natural Material. Mostly materials used in optics, such as water, glass, etc., have a positive value of permittivity and permeability while some of the materials, such as Silver and Gold have a Negative value of permittivity, but it also has a positive value of permeability (Pendry and Smith, 2004). In metamaterial, both permittivity and permeability are negative.
EBG stands for Electromagnetic bandgap metamaterial and it is used for controlling and manipulating the propagation of the electromagnetic wave. These could be accomplished by using either Photonic Crystal Material (PCM) or Left Handed Material (LHM) (Kumar et al., 2016).
A material is said as Chiral Material if its image is not superimposed. Types of Chiral Metamaterial Antenna are shown in Figure 4.
Figure 4. Types of Chiral Metamaterials Antenna
Example of Homogeneous and Homogenizable Chiral Metamaterials are,
Isotropic chiral materials have a random dispersion in handed molecules or inclusion, while randomness is the manifest at the macroscopic level for structurally chiral metamaterial. Subclassification of Structurally Chiral Metamaterial is shown in Figure 5.
Figure 5. Types of Structurally Chiral Metamaterials Antenna
Examples of Structurally Chiral Metamaterials are,
Chiral nematic atoms have a non-symmetric structure of atom molecules, while chiral sematic materials have a symmetric structure on the atom molecules. Fabrication methods for chiral metamaterial is shown in Figure 6. Fabrication of Chiral Metamaterial can be done by using Top down or Bottom up approach.
Figure 6. Fabrication Methods for Chiral Metamaterials Antenna
In Top down approach, fabrication starts with the smaller part of the structure and combines it to make the complete structure. The top down approach is widely used compared to bottom up and it can be further subclassified as Ion beam method, Electron beam lithography, and Direct laser writing as seen in Figure 6.
The advantages of Chiral Metamaterials Antenna are as follows.
The applications of Chiral Metamaterials Antenna are given below.
Based on the electric and magnetic response obtained from the structure, materials parameters, such as electric permittivity and magnetic permeability can be obtained and based on the value of this parameter, one can classify the material as SNG, DNG, and DPS. But there are many electromagnetic Metamaterials in which Electric field cause Magnetic polarization and Magnetic field cause electric polarization, e.g. Magneto electric coupling of such material is called as Bi-isotropic and this material that also exhibits magnetoelectric coupling is anisotropic and hence it is also called as a bi-anisotropic.
Terahertz metamaterial is the class of Metamaterial which interacts with the light in Terahertz (THz) frequency regime. The range of Terahertz Metamaterials is 0.1 THz to10 THz. At this frequency, wavelength is 3 mm and 0.03 mm and it is used in Extremely High Frequency (EHF) and Far Infrared (FIR) frequency band.
Photonic Metamaterial is also an artificial metamaterial. It is designed in such a way that it can interact with the optical frequency. Photonic Metamaterials are also called as Optical Metamaterials and it is fabricated for sub wavelength application. The periods of sub wavelength can be done by using Photonic Bandgap structure.
Frequency Selective Surface (FSS) metamaterial is first designed to control the transmission and reflection characteristics of the incident wave. This metamaterial substitutes with the fixed frequency metamaterial with static geometry and spacing between the metamaterial Unit cell, and it is used for finding out the frequency response of the given metamaterial. FSS Metamaterial allows us to change the frequency in the single medium while it is not possible in fixed frequency response. In FSS, different values of surface current are obtained compared to metallic conductor because it contains Artificial Magnetic Conductor (AMC).
Tunable Metamaterial is the material which has the capability to randomly adjust frequency changes in n (Refractive Index). Structure of Tunable material is changeable, so it is widely used for device reconfiguration during its operation. Tuning can be achieved in near Infrared by varying permittivity of nematic type liquid crystal.
Nonlinear Metamaterial is the material in which nonlinearity exist; it is fabricated by using a nonlinear device and is widely used in Nonlinear Optics (NLO). In Nonlinear Metamaterial, the property will change with change in the power of incident wave.
The main properties of metamaterials are shown in Figures 7 and 8. Figure 7 (a) shows parallel direction of phase and group velocity in RHM, while Figure 7 (b) shows the antiparallel direction of the phase velocity and group velocity. Figure 8 shows the negative index of the refraction.
Figure 7. Wave Propagation in RHM and LHM Media, (a) Isotropic RHM with Forward Wave, (b) Isotropic LHM with Backward Wave
Figure 8. Negative Refractive Index
There are various mathematical computational simulators available for designing and analysis of Metamaterial Unit cell. Some of the widely used techniques for designing and analysing metamaterials are given below.
There are many methods available for determining the property of wire metamaterial. Modeling of the metamaterial by using this method is important and a difficult task compared to other methods. By using this method different metamaterial structures can be constructed based on conducting thin wires.
Finite Element Methods are widely used for complex structure and in homogeneous anisotropic material. The software based on this method is High Frequency Structure Simulator (HFSS). Spurious Radiation problem can be solved using this method, by expanding the angular field component for node based scalar and transversal field component for edge based vector function.
By using Finite Difference Time Domain methods, various frequency dispersive and nondispersive materials can be modeled. Computer Simulation Technology (CST) Software is based on this method. The FDTD method is straightforward, robust, and efficient. This method allows us to construct metamaterial with a wide range of frequency. FDTD method is based on time domain solver and gives accuracy in both time and space.
Effective characterization of Metamaterial Unit cell can be done by extracting the parameters, such as Permittivity, Permeability, Refractive Index (n), and Impedance (Z). There are various methods available for parameter extraction from S- Parameter which are given below.
One simple method is that to put the object or material whose parameter wants to be found in the waveguide and then obtain S-parameter with respect to some reference point. Transmission Reflection methods are sometimes called as two coefficient methods. Transmission reflection method is the simplest method to directly extract the refractive index from the S-parameter ( Ashraf et al., 2017; Smith et al., 2002).
This method is widely used for effective parameter extraction of metamaterial because of its simplicity. By using this method, the permittivity and permeability can be easily extracted by using the S-parameter. This method does not have any Impedance calculation or branch index complexity ( Ji and Varadhan, 2016; Dhilon and Dimri, 2015).
Kramers-Kronig Relationship is the improved algorithm for metamaterial parameter extraction. Kramer-Kronig parameters work on the principle of causality. In this method, Metamaterial Homogeneous Slab is used to demonstrate the accuracy of retrieval parameter; Metamaterial Unit cell is made by using Split ring resonators and wires. This method gives more accurate parameter extraction.
One of the problems which occurs while extracting the Metamaterials’ permittivity and permeability is when the thickness of the substrate is increased, where it causes Branching problem (Szabó et al., 2010).
Directivity property of antenna can be enhanced by using the DNG metamaterial (Singh and Marwaha, 2015).
Bandwidth Enhancement can be done by using either left handed metamaterial or Superstrate of Metamaterial. Metamaterial shaveman ycapabilities for an electromagnetic application. However, the main disadvantages of the Passive metamaterials are Narrow bandwidth and Intrinsic Loss. These disadvantages can be solved by using the following methods
These things can be done by using active metamaterial and it gives negative conductivity which is not present in the conventional material. In their paper, Xin (2015) had demonstrated the active metamaterial with simultaneous negative value of attenuation constant and phase constant. Active metamaterial also provides desired broadband without trade-off with high loss(Xin, 2015).
In Rajak and chathoraj’s work, the proposed structures contain patch antenna at the bottom layer and metasurface at the top layer; Metasurface contains 30 number of unit cell as a radiating element. Radiating element has CSRR shape structure; with increased array of the metasurface, it causes change in the waves coming out from the surface and as a result bandwidth enhancement is obtained. Resonant frequency of the proposed antenna is 5.7 GHz and bandwidth is varied in the range of 70 to 140 MHz. So, the proposed structure is suitable for Wi-Fi application (Rajak and Chattoraj, 2016).
Radiation power can be enhanced by reducing the size of the antenna. It can be achieved by designing the antenna by using DNG metamaterial.
Beamwidth to side lobe ratio can be decreased by using a metamaterial.
Size of the metamaterial antenna can be reduced compared to the conventional antenna and hence it is also called as low profile antenna.
Nowadays it is required to design the single antenna that can be reconfigured in polarization, frequency, and pattern reconfiguration. Frequency reconfiguration can be easily achieved with the help of metamaterial antenna.
The gain of the metamaterial antenna can be increased by using additional element or array of metamaterial antenna For (e.g.) with the help of 10 × 10 Array, the 13.5 dBi Gain can be achieved ( El Badawe et al., 2016; Xin, 2015; Dubey and Dongre, 2016). The gain will decrease with increase in the scan angle.
In conventional antennas, distance between adjacent antennas is at least half (½) of its wavelength, but Metasurface antenna uses electrically very small antennas so it provides a good coupling between resonator and feed (El Badawe et al., 2016).
Invisibility cloaking is used to hide the object from the EM waves. Invisibility cloaking can be obtained by using Metamaterials. It is the emerging research area in the field of Stealth Technology. It is widely used in aerospace to hide warhead from Radio Detection and Ranging (RADAR) and in a automobile field. In earlier days, most of the demonstrated structure were planar, but there are many areas like Aerospace fuselage where conformal or flexible structures are required ( Jyothi et al., 2016; Rajak and Chattoraj, 2016).
Invisibility can be obtained by considering the following ways (Jyothi et al., 2016).
Two different multi-band metamaterial based microstrip antennas are used for designing Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) in Multiband Applications.
Metamaterials can be fabricated in various shapes, such as I shape, H shape, E shape, SRR, CSRR, Open split ring resonator, etc ( Uddin et al., 2016 ; Jyothi et al., 2016). Out of this, SRR and CSRR are widely used for WLAN and WiMAX applications.
Beam steering can be done by using metasurface antenna technology. This technology is used for beam steering of RF wave angle without using any mechanical or moving parts (Stevenson et al., 2016).
It is also used in Ka band high throughput satellite system (HTS), portable satellite hotspot application, Aeronautical applications, and Rail applications.
Due to low profile advantages of metamaterial it can be widely used in the field of antenna designing. In conventional antenna, reflected energy comes back to the source while metamaterial antenna stores this reflected energy and behaves as a large size of the antenna.
Nowadays, metamaterial antennas are widely used in the field of biosensors where it is used for disease diagnostics, weather monitoring, health monitoring, and food safety purpose. In earlier days, this field uses the fluorescence based method, but this method is costly compared to metamaterial method.
The metamaterial absorber is used for absorption of EM radiation. Compared to conventional radiation it has many advantages, such as Wide adaptability, Increased effectiveness, Supplementary miniaturization, etc.
Weapons of Mass Destruction (WMD) detectors are used in the field of Army and Air force for detection of chemical explosives, biological agents, and infectivity. It can also be used for screening passengers and cargo.
Metamaterials are also useful for improving Ultrasound Resolution by controlling the sound signal. It is also used to change the material's colour and nanoscale wrinkles by controlling the light signal.
Nowadays, researchers and army engineers are using metamaterials for high speed switching applications for small photonic devices. Switch can be turned ON and OFF by trapping the light, and compared to conventional switching techniques, it is 10 times faster.
Metamaterials are also used for building a Super Lens of high resolutions for small particles such as Deoxyribonucleic Acid (DNA). Conventional Lens obey the rules of RH while the metamaterials obey the rules of LH, so it is possible to achieve high resolution with the help of metamaterials.
Seismic metamaterials are designed in such a way that it can counteract with the seismic waves coming from the earth and protects the buildings.
A Radome is an integral part of almost all the antenna systems. It can be used for protecting the antenna and electronic parts from the external environment, such as cold, heat, humidity, etc. It is also possible to design microwave radomes by introducing the new concept of Metaradomes.
The metamaterial is also used for designing the bandpass filters. When the Bandpass filter is designed by using a metamaterial, the size of the filter will reduce and the performance will be improved compared to conventional filters.
Electromagnetic Radiations absorbed by the Human body is represented in terms of Specific Absorption Rate (SAR). EM radiation is hazardous to human health. If the antenna is designed by metamaterials, then the value of SAR is significantly reduced compared to the conventional antenna.
The couplers can also be designed by combining right handed material and left handed material for performance improvement and loss, reduction.
The Blackhole is the region of space which absorbs everything hitting it. In the black hole, all the objects have an event horizon radius, but different values of gravitational field. Blackhole can also be formed by using metamaterial because it contains the same behaviour.
The metamaterials can also be used in many other fields, such as High frequency better field communication, in wireless and space communication, and in the field of a new era of microwave research.
Unit cell is a basic building block of Metasurface. There are various types of metamaterial unit cells available and it can be constructed by just changing the shape of the patch.
Figure 9. SRR Shape Metamaterial Unit Cell
Out of these two conducting elements, SRR is located at the top of the substrate, while wire is located at the bottom of the substrate. SRR responds magnetically to the electromagnetic field and it provides negative permeability, while the wire responds electrically to the electromagnetic field and it provides negative permittivity.
First, Dr. Smith demonstrated that the combined structure (SRR + Wire) gives simultaneous negative value of permittivity and permeability. In this proposed Metamaterial Unit cell, Perfect Electric Field (PE) Boundary is assigned in XDirection, while Perfect Magnetic Field (PM) is assigned in ZDirection, and Wave port is assigned in Y- Direction.
The dimensions of the proposed Metamaterial Unit cell are shown in Table 1.
Table 1. Dimensions of SRR Shape Metamaterial Unit Cell
The proposed Metamaterial Unit cell is Cubic in shape. As per Table 1, Cell dimension of proposed metamaterial unit cell is d=2.5 mm. The substrate is made by the FR-4 Epoxy with thickness 0.25 mm, loss tangent 0.02, dielectric constant 4.4, and thickness of the copper as 0.017 mm. The proposed metamaterial unit cell contains two rings. The length of the outer ring is 2.2 mm, slot size (gap) in each ring is 0.3 mm, gap between inner and outer ring is 0.15 mm, and both the rings have same line width of 0.2 mm.
Figure 10. Omega Shaped Metamaterial Unit cell
This metamaterial unit cell contains two types of conducting element, viz. Omega Shape and Wire.
Out of these two conducting elements, Omega shape is located at the top of the substrate, while wire is located at the bottom of the substrate. Omega shape responds magnetically to the electromagnetic field and provides negative permeability, while wire responds electrically to the electromagnetic field and provides negative permittivity. The dimensions of the proposed Metamaterial Unit cell are shown in Table 2. The proposed Metamaterial Unit cell has Cubic shape. Cell dimension of the proposed metamaterial unit cell is d=4 mm. The substrate is made by the FR-4 Epoxy with thickness 0.8 mm and loss tangent is 0.02 and dielectric constant is 4.4, thickness of the copper is 0.017 mm. In the proposed Metamaterial Unit cell, length of the wire is 4 mm, width of the wire is 0.5 mm, and size of the slot is 0.5 mm. Design parameters of Omega shaped metamaterial unit cell is shown in Table 2.
Table 2. Dimension of Omega Shape Metamaterial Unit cell
In this unit cell, Roger RO 3010 is used as a substrate which has dielectric constants 10.2. Simulation of this unit cell is carried out by using CST Microwave Studio and the Resonance frequency of the presented structure is 7.89 GHz. Metamaterial provides some surprising property which is not found in nature; Metamaterials are used to manipulate and control the wave and light, and many other physical phenomena (Ashraf et al., 2017). Various shaped Metamaterial Unit cells are available like E shaped, H Shaped, Omega shaped, U shaped, and so on. Out of this, H shaped unit cells are used in C and S bands, while Pi shaped cells are used for X and C band applications. Out of the two methods, NRW methods were used because of its simplicity compared to other methods. They have demonstrated NRW and TR methods (Ashraf et al., 2017).
For the analysis of material permittivity and permeability, it is required to consider three configurations, namely Wire structure, SRR resonator, and combination of both wired and SRR structure. Wire structure is responsible for the Negative permittivity and SRR structure is responsible for Negative permeability and combination of both simultaneously gives permittivity and permeability. Transmission and reflection parameter of S-Parameter was calculated and the value of Refractive index n and impedance z was obtained. By using the following equations (1) and (2), the value of permittivity and permeability are obtained (Smith et al., 2016).
The method used for the extraction of material permittivity and permeability was NRW method. The use of artificial metamaterial has increased rapidly due to variety of characteristics provided by the metamaterial like negative permittivity and negative permeability which is not available in natural material. Permittivity and permeability are the most important parameters to determine the propagation of wave in matter. In a wireless and space borne application, it requires compact radiator antenna with large bandwidth. The permittivity is a measure of net electrical dipole moment per unit volume generated by the material while the permeability is a measure of generated magnetic dipole moment per unit volume. This parameter can tell us about different properties like Refractive index, Phase velocity, Loss, and Impedance.
Following four methods are widely used for the Extraction of Metamaterial parameter extraction.
Out of the above mentioned methods, Kramer-Kronig Relationship is the improved algorithm for extraction of metamaterials parameter. Here Metamaterial Homogeneous Slab is used to demonstrate the accuracy of retrieval parameter; Metamaterial Unit cells are made by using Split ring resonators and wires (Szabó et al., 2010).
Following problems arise while extracting the Metamaterial parameters like Permittivity, Permeability, Impedance, and Refractive Index.
Kramer-Kronig parameters works on the principle of causality. Branching problem affects directly the real part of refractive index. To avoid this ambiguity, Kramers-Kronig relationship derives real part of n from imaginary part of n. When thickness of Metamaterial increase, it is compared with wavelength and at that time, effective medium theory gets failed because of the discontinuity in refractive index (Szabó et al., 2010).
Metamaterial Unit cell is designed by using HFSS 2017 (Ansoft), parameters such as permittivity, permeability, impedance, and refractive index are obtained by using MATLAB, and S-Parameter is obtained by using HFSS. Parameters such as permittivity, permeability, impedance, and refractive index can also be obtained by using output variable in HFSS or it can also be obtained by using CST. The structure can also be designed by using CST Microwave Studio and it is based on Finite Distribution Time Domain Analysis.
First of all, the Metamaterial Unit Cell is designed by using HFSS. Any antenna designing software like COMSOL Multi physics or CST Software can be used for designing and analysing of metamaterial Unit cell.
Step 2:The second step is to allocate proper boundary condition to assign Perfect Electric Boundary, Perfect Magnetic Boundary and Wave port as per the design of the structure.
Step 3:The design is analyzed from the obtained results.
Step 4:<\i><\b>After analysing, the S-parameter is obtained by using Rectangular plot, then the real and imaginary part of transmission coefficient (S21) and Reflection coefficient (S11) are also obtained.
Step 5:These two results are exported separately either in Text format (.text) or CSV (Comma Separated Value) (.csv)./p>
Step 6:Both these formats can be read in MATLAB by using different Commands, e.g. text read command for .text extension file while csvread for .csv extension file.
Step 7:Appropriate equation is written on MATLAB based on the method chosen like NRW, TR, Kramers-Kronig, etc.
Step 8:The graph of the different parameters are plotted for further evaluation.
Metamaterials attract many researchers because of its unique EM properties and their application. In this paper, history of metamaterials, its classification properties, advantages, and various applications of metamaterials, design of Metamaterial Unit cell, problems and solution during parameter extraction have been discussed. Identification of the metamaterial behaviour can be done by the knowledge of Negative permittivity and Negative permeability and Negative index of Refraction, Materials permittivity and permeability can be obtained by Nicolson Ross Weir (NRW), Transmission Reflection (TR), and Kramers- Kronig relationship. There are several software simulation methods available, such as Transmission Line method (TL), Finite Difference Time Domain Methods (FDTD), and Finite Element Method (FEM) to design and analyse the Metamaterial antenna. Metamaterials can offer exciting possibilities in the future design of component and device. Metamaterials is a new era of research because it offers new electromagnetic properties which cannot be offered by the natural material. By using metamaterials, one can design or solve the entire problem, such as Super Lens, Invisibility Cloaking, Revolutionary Electronics, WMD Detectors, Biosensor, Metamaterial Absorber, Seismic field, etc., which are not possible with right handed materials.