Int. Journal of Electrical & Electronics Engg.
Vol. 2, Spl. Issue 1 (2015)
e-ISSN: 1694-2310 | p-ISSN: 1694-2426
Investigation on Frequency Analysis of Metamaterial Structure Rajni
Gursharan Kaur, Amanpreet Kaur
Dr. Anupma Marwaha
Associate Professor, Department of ECE SBSSTC, (PTU, Kapurthala)
M.Tech. Research Scholar, Department of ECE SBSSTC, (PTU, Kapurthala)
Associate Professor Department of ECE SLIET (Deemed University), Longowal
rajni_c123@yahoo.co.in,
gursharankaur07@gmail.com, amannatkaur@gmail.com
Abstract - In this work, a Split Ring Resonator (SRR) unit cell is simulated in a waveguide with electromagnetic field solver High Frequency Structure Simulator (HFSS). Analytical calculations of the inductance and capacitance have been also carried out to obtain the resonant frequencies for SRR dimensions. A comparison between calculated and simulated resonance frequencies)) is done. A good correlation between simulated and measured resonance frequencies is achieved. Index Terms – Split Ring Resonator (SRR), Metamaterial, Unit cell, resonant frequency.
I. INTRODUCTION Antennas are gaining attention due to their vital role in today’s world of wireless communication systems. There are a lot of techniques have been used by researchers to to enhance the antenna performance parameters. Use of Metamaterials (structure based materials) in antennas on ground, patch or substrate is one of these techniques. In 1967, Veselago through his theoretical investigation proved the existence of metamaterial [1]. Metamaterials are engineered materials that have unnatural physical properties that are not found in nature. These metamaterial exhibits negative permeability (μ) and negative permittivity (ε) and are defined as double negative materials (DNG). In case of single negative metamaterial, the only permeability (μ) negative materials are known as mu negative (MNG) and only permittivity (ε) negative materials are epsilon negative (ENG) materials. Metamaterial structure is comprised of SRR and thin wire elements that generates negative permeability and negative permittivity respectively. The concept of metamaterial has reversed the Snell's law, Doppler Effect, Cheronkov radiation because of its unconventional properties [2-5]. In 1981 the first ‘split ring resonator’ was invented by Hardy [6]. In 1999 the periodic array of conducting nonmagnetic rings known as SRR was first used to attain negative permeability and proved by Pendry [7] and nowadays has become the popular metamaterial component. There are many structures of different types of SRR are available, such as double split SRR (DS-SRR), broadside couple SRR (BC-SRR), spiral SRR (S-SRR) and edge coupled SRR (EC-SRR). SRR is considered as an important artificial atom for the artificial media’s design and fabrication. However, there are still some parameters of SRR that have scope of an improvement. The idea behind this work is to investigate the performance of nine models of SRR obtained by varying its parameters dimension. In this work, a double split ring structure has been considered as a unit cell and investigation is done on NITTTR, Chandigarh
EDIT -2015
marwaha_anupma@yahoo.co.in
SRR instead of an array to simplify analysis and performance calculation. Dimensions of SRR are varied and comparison for calculated and resonating frequency has been carried out for different models. The Ansoft HFSS software is used to analyse various parameters of SRR models. II. SRR UNIT CELL DESIGN The SRR cell consists of concentric rings with cuts (splits) at the opposite ends. Rings have small spacing between them and are made of copper like metals. The magnetic flux will generate the rotating currents in the rings, in response to which rings produce their own flux to intensify the incident field. Presence of splits in the ring leads to resonant wavelengths greater than the diameters of the rings. Figure1 illustrates a dual split ring resonator (SRR), a highly conductive structure having inductance adjusted by the capacitance between the two rings.
Figure 5. Geometry of a Split Ring Resonator with dimensions.
The SRR is placed above the Rogers RT/duroid substrate 5880 of thickness of 3.175 mm, relative permittivity ( ) of 2.2 and loss tangent is 0.0009. The unit cell is enclosed in a waveguide. Perfect electric conductor boundaries are assigned to both faces of the X axis. Perfect magnetic conductor boundary conditions are assigned at top and bottom of the Z-axis. The unit cell is excited by the waveports. Wave penetrates through the two waveguide ports assigned on Y-axis. [8]. Figure 2 presents a structure of SRR inside waveguide.
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