Coupling Schemes in Terahertz Planar Metamaterials

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.

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Effects of Microstructure Variations on Macroscopic Terahertz Metafilm Properties

Active and Passive Electronic Components ◽

10.1155/2007/49691 ◽

2007 ◽

Vol 2007 ◽

pp. 1-10 ◽

Cited By ~ 30

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.

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Coupled ring resonator for microwave characterization of dielectric materials

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078711001103 ◽

2012 ◽

Vol 4 (2) ◽

pp. 241-246 ◽

Cited By ~ 2

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.

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Modeling of Split Ring Resonators loaded microstrip line with different orientations

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v5i6.pp1363-1371 ◽

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

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. 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. The simulation of different orientations of split ring resonator gives better reflection coefficient and wider frequency.

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Multiband transparency effect induced by toroidal excitation in a strongly coupled planar terahertz metamaterial

Scientific Reports ◽

10.1038/s41598-021-98498-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Angana Bhattacharya ◽

Rakesh Sarkar ◽

Naval K. Sharma ◽

Bhairov K. Bhowmik ◽

Amir Ahmad ◽

...

Keyword(s):

Coupled Oscillators ◽

Ring Resonator ◽

Near Field ◽

Split Ring Resonator ◽

Split Ring ◽

Strongly Coupled ◽

Future Studies ◽

High Q ◽

Field Coupling ◽

Sensing Applications

AbstractThe multiband transparency effect in terahertz (THz) domain has intrigued the scientific community due to its significance in developing THz multiband devices. In this article, we have proposed a planar metamaterial geometry comprised of a toroidal split ring resonator (TSRR) flanked by two asymmetric C resonators. The proposed geometry results in multi-band transparency windows in the THz region via strong near field coupling of the toroidal excitation with the dipolar C-resonators of the meta molecule. The geometry displays dominant toroidal excitation as demonstrated by a multipolar analysis of scattered radiation. High Q factor resonances of the metamaterial configuration is reported which can find significance in sensing applications. We report the frequency modulation of transparency windows by changing the separation between TSRR and the C resonators. The numerically simulated findings have been interpreted and validated using an equivalent theoretical model based upon three coupled oscillators system. Such modeling of toroidal resonances may be utilized in future studies on toroidal excitation based EIT responses in metamaterials. Our study has the potential to impact the development of terahertz photonic components useful in building next generation devices.

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

Electronics ◽

10.3390/electronics8020202 ◽

2019 ◽

Vol 8 (2) ◽

pp. 202 ◽

Cited By ~ 4

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.

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Near-field THz imaging of a split ring resonator matrix

2011 International Conference on Infrared, Millimeter, and Terahertz Waves ◽

10.1109/irmmw-thz.2011.6105043 ◽

2011 ◽

Author(s):

F. Blanchard ◽

A. Doi ◽

T. Tanaka ◽

H. Hirori ◽

J. Darmo ◽

...

Keyword(s):

Ring Resonator ◽

Near Field ◽

Split Ring Resonator ◽

Thz Imaging ◽

Split Ring

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Efficient and Compact Near-Field Coupled Hybrid Antenna Using a Single Radiating Subwavelength Split-Ring Resonator

Electronics ◽

10.3390/electronics8050527 ◽

2019 ◽

Vol 8 (5) ◽

pp. 527

Author(s):

Zinching Dang ◽

Marco Rahm

Keyword(s):

Resonance Frequency ◽

Electromagnetic Waves ◽

Ring Resonator ◽

Near Field ◽

Low Frequency ◽

Split Ring Resonator ◽

Dipole Antenna ◽

Angular Width ◽

Split Ring ◽

Broadband Internet

Modern applications in the realms of wireless communication and mobile broadband Internet increase the demand for compact antennas with well defined directivity. Here, we present an approach for the design and implementation of hybrid antennas consisting of a classic feeding antenna that is near-field-coupled to a subwavelength resonator. In such a combined structure, the composite antenna always radiates at the resonance frequency of the subwavelength oscillator as well as at the resonance frequency of the feeding antenna. While the classic antenna serves as impedance-matched feeding element, the subwavelength resonator induces an additional resonance to the composite antenna. In general, these near-field coupled structures are known for decades and are lately published as near-field resonant parasitic antennas. We describe an antenna design consisting of a high-frequency electric dipole antenna at f d = 25 GHz that couples to a low-frequency subwavelength split-ring resonator, which emits electromagnetic waves at f SRR = 10.41 GHz. The radiating part of the antenna has a size of approximately 3.2 mm × 8 mm × 1 mm and thus is electrically small at this frequency with a product k · a = 0.5 . The input return loss of the antenna was moderate at − 18 dB and it radiated at a spectral bandwidth of 120 MHz. The measured main lobe of the antenna was observed at 60 ∘ with a − 3 dB angular width of 65 ∘ in the E-plane and at 130 ∘ with a − 3 dB angular width of 145 ∘ in the H-plane.

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