scholarly journals Effects of Microstructure Variations on Macroscopic Terahertz Metafilm Properties

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
John F. O'Hara ◽  
Evgenya Smirnova ◽  
Abul K. Azad ◽  
Hou-Tong Chen ◽  
Antoinette J. Taylor
Keyword(s):  
Ring Resonator ◽  
Single Layer ◽  
Split Ring Resonator ◽  
Ring Resonators ◽  
Terahertz Frequency ◽  
Structural Components ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Split Ring ◽  
Split Ring Resonators

The properties of planar, single-layer metamaterials, or metafilms, are studied by varying the structural components of the split-ring resonators used to comprise the overall medium. Measurements and simulations reveal how minor design variations in split-ring resonator structures can result in significant changes in the macroscopic properties of the metafilm. A transmission-line/circuit model is also used to clarify some of the behavior and design limitations of the metafilms. Though our results are illustrated in the terahertz frequency range, the work has broader implications, particularly with respect to filtering, modulation, and switching devices.

scholarly journals Coupling Schemes in Terahertz Planar Metamaterials

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Dibakar Roy Chowdhury ◽  
Ranjan Singh ◽  
Antoinette J. Taylor ◽  
Hou-Tong Chen ◽  
Weili Zhang ◽  
...  
Keyword(s):  
Resonance Line ◽  
Ring Resonator ◽  
Near Field ◽  
Split Ring Resonator ◽  
Higher Order ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Sensing Applications ◽  
Lattice Mode

We present a review of the different coupling schemes in a planar array of terahertz metamaterials. The gap-to-gap near-field capacitive coupling between split-ring resonators in a unit cell leads to either blue shift or red shift of the fundamental inductive-capacitive (LC) resonance, depending on the position of the split gap. The inductive coupling is enhanced by decreasing the inter resonator distance resulting in strong blue shifts of theLCresonance. We observe theLCresonance tuning only when the split-ring resonators are in close proximity of each other; otherwise, they appear to be uncoupled. Conversely, the higher-order resonances are sensitive to the smallest change in the inter particle distance or split-ring resonator orientation and undergo tremendous resonance line reshaping giving rise to a sharp subradiant resonance mode which produces hot spots useful for sensing applications. Most of the coupling schemes in a metamaterial are based on a near-field effect, though there also exists a mechanism to couple the resonators through the excitation of lowest-order lattice mode which facilitates the long-range radiative or diffractive coupling in the split-ring resonator plane leading to resonance line narrowing of the fundamental as well as the higher order resonance modes.

Coupled ring resonator for microwave characterization of dielectric materials

2012 ◽  
Vol 4 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Mahima Kapoor ◽  
K. S. Daya ◽  
G. S. Tyagi
Keyword(s):  
Dielectric Constant ◽  
Spirulina Platensis ◽  
Ring Resonator ◽  
Dielectric Materials ◽  
Split Ring Resonator ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Closed Ring

In this paper characterization of dielectric materials in liquid and powder phase using concentric closed and split ring resonators of length λ, λ/2, and λ/4 is reported. Experimental results have been validated by simulations and theoretically modeling. Sensitivity of the resonator with closed rings was maximum. Experimentally extracted values of dielectric constant of ferrite ranged from 14.05 to 15.1 with closed ring resonators and from 13.6 to 14.02 with split ring resonator, respectively. For spirulina platensis the dielectric constant was lying in the range 1.78–1.93 and 1.74–2.04 with closed ring and split ring resonators, respectively. The values extracted experimentally are in good agreement with simulation and theoretically found values. However, the values obtained from closed ring resonator were in agreement with the dielectric constant values of ferrite and spirulina platensis.

scholarly journals Modeling of Split Ring Resonators loaded microstrip line with different orientations

2015 ◽  
Vol 5 (6) ◽  
pp. 1363
Author(s):  
Rajni Rajni ◽  
Gurwinder Singh ◽  
Anupma Marwaha
Keyword(s):  
Reflection Coefficient ◽  
Microstrip Line ◽  
Ring Resonator ◽  
Magnetic Interaction ◽  
Split Ring Resonator ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
High Frequency Structure Simulator ◽  
Equivalent Circuit Parameters

<p>This paper presents the different circuit approaches of the electric and magnetic interaction of Single Split Ring Resonator (SRR) loaded microstrip line. We loaded the microstrip line with planar square split ring resonator in different configurations and orientations. The modeling behavior of metamaterials-based microstrip lines loaded with single and two-mirrored split ring resonators is analyzed numerically in two orientations (with gap of SRR parallel and perpendicular to the line). The full wave simulations are performed for the single and two-mirrored split ring resonators loaded microstrip inside a waveguide with ‘High Frequency Structure Simulator’ software.<strong> </strong>The equivalent circuit parameters are obtained for the single split ring resonator loaded with microstrip line with the gap parallel and near to the line from transmission line theory  that make use of just the resonance frequency and minimum of the reflection coefficient.<strong> </strong>The simulation of different orientations of split ring resonator gives better reflection coefficient and wider frequency.</p>

scholarly journals A Novel SWB Antenna with Triple Band-Notches Based on Elliptical Slot and Rectangular Split Ring Resonators

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 202 ◽  
Author(s):  
Xiaobo Zhang ◽  
Saeed Ur Rahman ◽  
Qunsheng Cao ◽  
Ignacio Gil ◽  
Muhammad Irshad khan
Keyword(s):  
Split Ring Resonator ◽  
Ring Resonators ◽  
Impedance Bandwidth ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Compact Size ◽  
Good Agreement ◽  
Swb Applications ◽  
Triple Band ◽  
Microstrip Feed

In this paper, a wideband antenna was designed for super-wideband (SWB) applications. The proposed antenna was fed with a rectangular tapered microstrip feed line, which operated over a SWB frequency range (1.42 GHz to 50 GHz). The antenna was implemented at a compact size with electrical dimensions of 0.16 λ × 0.27 λ × 0.0047 λ mm3, where λ was with respect to the lowest resonance frequency. The proposed antenna prototype was fabricated on a F4B substrate, which had a permittivity of 2.65 and 1 mm thickness. The SWB antenna exhibited an impedance bandwidth of 189% and a bandwidth ratio of 35.2:1. Additionally, the proposed antenna design exhibited three band notch characteristics that were necessary to eradicate interference from WLAN, WiMAX, and X bands in the SWB range. One notch was achieved by etching an elliptical split ring resonator (ESRR) in the radiator and the other two notches were achieved by placing rectangular split ring resonators close to the signal line. The first notch was tuned by incorporating a varactor diode into the ESRR. The prototype was experimentally validated with, with notch and without notch characteristics for SWB applications. The experimental results showed good agreement with simulated results.

Interaction of single-layer CVD graphene with a metasurface of terahertz split-ring resonators

2013 ◽  
Author(s):  
Federico Valmorra ◽  
Giacomo Scalari ◽  
Curdin Maissen ◽  
Wangyang Fu ◽  
Christian Schönenberger ◽  
...  
Keyword(s):  
Single Layer ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Cvd Graphene

Tunable and switchable resonance in optically-controlled nested metamaterials at terahertz frequencies

2016 ◽  
Vol 30 (03) ◽  
pp. 1650011
Author(s):  
Yong-Li Che ◽  
Xiao-Long Cao ◽  
Jian-Quan Yao
Keyword(s):  
Gallium Arsenide ◽  
Quartz Substrate ◽  
Optical Excitation ◽  
Ring Resonators ◽  
Metallic State ◽  
Frequency Range ◽  
Metamaterial Structure ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Terahertz Frequencies

The asymmetrical nested metamaterial, composed of two split-ring resonators (SRRs) and two embedded gallium arsenide (GaAs) islands placed in the two SRRs, has been elaborately designed on quartz substrate. Its tunable and switchable resonances at terahertz (THz) frequencies are numerically demonstrated here based on different conductivities of GaAs, which can be transformed from semiconductor to metallic state through appropriate optical excitation. Without photoexcitation, our designed metamaterial has three resonance peaks in the range of monitored frequency range, and they are located at 0.813, 1.269 and 1.722 THz, respectively. As the conductivity of the two GaAs islands increases, different new resonances appear and constantly strengthen. Finally, four new resonant points are generated, at 0.432, 0.948, 1.578 and 1.875 THz, respectively. At the same time, the metamaterial structure is changed from the original nested mode to a new integral mode. Applying reversible changing conductivity of semiconductor to push the conversion of resonance, this asymmetrical nested design provides a new instance in application and development of additional THz devices.

Analytical circuit model for split ring resonators in the far infrared and optical frequency range

Metamaterials ◽  
2009 ◽  
Vol 3 (2) ◽  
pp. 57-62 ◽  
Author(s):  
V. Delgado ◽  
O. Sydoruk ◽  
E. Tatartschuk ◽  
R. Marqués ◽  
M.J. Freire ◽  
...  
Keyword(s):  
Far Infrared ◽  
Circuit Model ◽  
Ring Resonators ◽  
Optical Frequency ◽  
Frequency Range ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Optical Frequency Range

scholarly journals Design and evaluation of split-ring resonators for aptamer-based biosensors

2018 ◽  
Vol 7 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Tobias Reinecke ◽  
Johanna-Gabriela Walter ◽  
Tim Kobelt ◽  
André Ahrens ◽  
Thomas Scheper ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Split Ring Resonator ◽  
Target Protein ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Molecular Binding ◽  
Novel Approach ◽  
Highly Sensitive ◽  
Line Theory

Abstract. Split-ring resonators are electrical circuits, which enable highly sensitive readout of split capacity changes via a measurement of the shift in the resonance frequency. Thus, functionalization of the split allows the development of biosensors, where selective molecular binding causes a change in permittivity and therefore a change in split capacity. In this work, we present a novel approach using transmission line theory to describe the dependency between permittivity of the sample and resonance frequency. This theory allows the identification of all relevant parameters of a split-ring resonator and thus a target-oriented optimization process. Hereby all setup optimizations are verified with measurements. Subsequently, the split of a resonator is functionalized with aptamers and the sensor response is investigated. This preliminary experiment shows that introducing the target protein results in a shift in the resonance frequency caused by a permittivity change due to aptamer-mediated protein binding, which allows selective detection of the target protein.

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