Identification tag in the terahertz frequency domain using low-cost and tunable refractive index materials

AbstractIn this paper, a meander-lines-based epsilon negative (ENG) metamaterial (MTM) with a high effective medium ratio (EMR) and near-zero refractive index (NZI) is designed and investigated for multiband microwave applications. The metamaterial unit cell is a modification of the conventional square split-ring resonator in which the meander line concept is utilized. The meander line helps to increase the electrical length of the rings and provides strong multiple resonances within a small dimension. The unit cell of proposed MTM is initiated on a low-cost FR4 substrate of 1.5 mm thick and electrical dimension of 0.06λ × 0.06λ, where wavelength, λ is calculated at the lowest resonance frequency (2.48 GHz). The MTM provides four major resonances of transmission coefficient (S21) at 2.48, 4.28, 9.36, and 13.7 GHz covering S, C, X, and Ku bands. It shows negative permittivity, near-zero permeability, and near-zero refractive index in the vicinity of these resonances. The equivalent circuit is designed and modeled in Advanced Design System (ADS) software. The simulated S21 of the MTM unit cell is compared with the measured one and both show close similarity. The array performance of the MTM is also evaluated by using 2 × 2, 4 × 4, and 8 × 8 arrays that show close resemblance with the unit cell. The MTM offers a high effective medium ratio (EMR) of 15.1, indicating the design's compactness. The frequency hopping characteristics of the proposed MTM is investigated by open and short-circuited the three outer rings split gaps by using three switches. Eight different combinations of the switching states provide eight different sets of multiband resonances within 2–18 GHz; those give the flexibility of using the proposed MTM operating in various frequency bands. For its small dimension, NZI, high EMR, and frequency hopping characteristics through switching, this metamaterial can be utilized for multiband microwave applications, especially to enhance the gain of multiband antennas.

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Calculation of the amount of free water molecules in aqueous solutions by means of spectral parameters from the terahertz frequency domain taking into account processes of screening

BIOPHYSICS ◽

10.1134/s0006350914030178 ◽

2014 ◽

Vol 59 (3) ◽

pp. 347-350 ◽

Cited By ~ 6

Author(s):

N. V. Penkov ◽

V. A. Yashin ◽

E. E. Fesenko ◽

E. E. Fesenko

Keyword(s):

Aqueous Solutions ◽

Frequency Domain ◽

Free Water ◽

Water Molecules ◽

Terahertz Frequency ◽

Spectral Parameters

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Low-Cost Heat Insulating Film Design for BIPV Modules Based on Multi-Layer Inorganic Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.452-453.1424 ◽

2012 ◽

Vol 452-453 ◽

pp. 1424-1428

Author(s):

Han Min Tian ◽

Li Jia Guo ◽

Wen Feng Duan ◽

Rui Xia Yang ◽

Feng Lan Tian

Keyword(s):

Refractive Index ◽

Visible Light ◽

Absorption Rate ◽

Heat Insulation ◽

Low Cost ◽

Heat Rate ◽

Optimum Combination ◽

Inorganic Materials ◽

Tempered Glass ◽

Glass Panel

By analyzing the transmitionce and heat rate of insulating antireflection films conposed by refractive-index adjustable SiO2 layer and TiO2 layers, the optimum combination of antireflection films of BIPV is obtained. The absorption rate at the ultraviolet part that wavelenght excessive inadequate 400nm of the optimized fils is 99.9%, which are directly designed on the surface of the low iron tempered glass panel of BIPV, and in the wavelength range 400nm-800nm, the visible light transmitionce rate is up to 99.5%, and the heat that wavelenght excessive 800nm is reflected of 20%. For the multilayer heat insulation films are composed with the same kind of material while with different refractive indexes, there is no projecting stress between these films and no constraints during the production process of different films for the possible low cost heat insulating of BIPV.

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Development of Low-Cost Abbe Refractometer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.879.227 ◽

2018 ◽

Vol 879 ◽

pp. 227-233

Author(s):

Weeratouch Pongruengkiat ◽

Thitika Jungpanich ◽

Kodchakorn Ittipornnuson ◽

Suejit Pechprasarn ◽

Naphat Albutt

Keyword(s):

Refractive Index ◽

Optical Materials ◽

Low Cost ◽

Optical Component ◽

Refractive Indices ◽

Constant Number ◽

Optical Wavelength ◽

Refractive Index Spectrum ◽

Transparent Polymers ◽

Abbe Refractometer

Refractive index and Abbe number are major physical properties of optical materials including glasses and transparent polymers. Refractive index is, in fact, not a constant number and is varied as a function of optical wavelength. The full refractive index spectrum can be obtained using a spectrometer. However, for optical component designers, three refractive indices at the wavelengths of 486.1 nm, 589.3 nm and 656.3 nm are usually sufficient for most of the design tasks, since the rest of the spectrum can be predicted by mathematical models and interpolation. In this paper, we propose a simple optical instrumental setup that determines the refractive indices at three wavelengths and the Abbe number of solid and liquid materials.

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