The grooved‐dielectric Fresnel zone plate: An effective terahertz lens and antenna

Hristov, H.D.; Rodríguez, José María Fernández; Grote, Walter

doi:10.1002/mop.26812

Cited by 33 publications

(12 citation statements)

References 11 publications

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“…Terahertz lenses are typically made of plastics such as polyethylene or TPX. Recently, the significant innovations allow the rapid production of a large number of lenses [90]that include Fresnel zone plates [91], plasmonic resonances [92], variable focal length lenses [93], 3D printed diffractive lenses [94], and even THz lenses made of paper [95]. Polarizers are essential components in THz imaging, communications, and spectroscopy.…”

Section: B the Thz Componentsmentioning

confidence: 99%

State-of-the-art in terahertz sensing for food and water security – A comprehensive review

Ren

Zahid

Fan

et al. 2019

Trends in Food Science & Technology

124

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Past few years have witness a dramatic change in the field of terahertz (THz) technology. The recent advancements in the technology for generation, manipulation and detection exploiting THz radiation have brought revolution in the field. Many researchers around the world have been inspired by the potential of invaluable new applications of THz sensing for food and water contamination detection. The microbial pollution in water and food is one the crucial issues with regard to the sanitary state for drinking water and daily consumption of food. To address this risk, the detection of microbial contamination is of utmost importance since the consumption of insanitary or unhygienic food can lead to catastrophic illness. This paper presents a first-time review of the open literature focused on the advances in the THz sensing for microbiological contamination of food and water and state-of-theart network architectures, applications, industrial trends and recent developments. Finally, open challenges and future research directions are presented with in the field.

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Section: B the Thz Componentsmentioning

confidence: 99%

State-of-the-art in terahertz sensing for food and water security – A comprehensive review

Ren

Zahid

Fan

et al. 2019

Trends in Food Science & Technology

124

View full text Add to dashboard Cite

show abstract

“…1(a) , a Fresnel zone plate is a planar symmetric gradient index structure with a z-axis in the center. Therefore, by providing axially symmetric illumination 9 for feeding lens apertures, the zone plate’s radiation patterns should be symmetrical with high gains and high efficiency at the focusing point (P1). Therefore, we can verify that any asymmetrical zone plate’s radiation is due to permittivity estimation errors in the homogeneous design principles.…”

Section: Permittivity Control With Materials Porosity Methods For Zp Zomentioning

confidence: 99%

“…Deforming rigid material structures such as air-holes, cube-shaped structures, or material pressing are an apparent material porosity methods to control intrinsic permittivity 1 , 7 , 8 . Among GRIN lenses, Fresnel Zone Plates (FZP), due to their planar merit, reduced weight, ease of fabrication, and cost-effectiveness are relatively more attractive structures to achieve high-gain focus in the millimeter and sub-millimeter wave spectrum 5 , 9 – 12 . Nevertheless, there are only a few studies on controlling the permittivities of phase correction zones with plastic porosity and experimental realization of the planar focus lens geometries.…”

Section: Introductionmentioning

confidence: 99%

Towards Millimeter-wavelength: Transmission-Mode Fresnel-Zone Plate Lens Antennas using Plastic Material Porosity Control in Homogeneous Medium

Pourahmadazar

Denidni

2018

Sci Rep

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We present two transmission-mode dielectric Fresnel-Zone Plate Lens (FZPL) antennas for use within the V-band spectrum. The proposed FZPs are realized via pure plastic material using two different additive manufacturing processes. The proposed FZP lenses are designed with half (λ/2) and quarter (λ/4) phase correction rings at 60-GHz with 30λ0 diameter, where λ0 is the free-space wavelength. The permittivity effect for lens sub-zones is controlled by material porosity in cube-shaped structures. The 3D printed zone plate lenses are built using additive manufacturing plastic materials with a thickness of λ0 and constant relative permittivities equal to 2.76 and 3.6. Different types of antenna with cosn-like radiation patterns as lens illuminators are analyzed on the vertical plane of the flat lenses to have a high efficiency over the considered operating band. Simulations and experimental measurements show a reasonably close match, therefore allowing for a reliable predictability.

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“…Additionally, feed considerations, losses, far-field patterns, multiplefrequency operation, and many more were analyzed. A thorough description of Fresnel zone plate antennas (FZPA) in different configurations was given by groups of Matti H. A. J. Herben and Hristo D. Hristov- [51][52][53][54][55][56][57]. Their work on FZPAs was supplemented by Paul F. Goldsmith [58] and Glenn S. Smith groups [46,59] and [60].…”

Section: Fresnel Zone Plates and Diffractive Lensesmentioning

confidence: 99%

Terahertz Diffractive Optics—Smart Control over Radiation

Siemion

2019

J Infrared Milli Terahz Waves

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Over the last 20 years, thin and lightweight optical elements have become very desirable, especially for the terahertz (THz) range. Reduction of the volume of optical elements alongside an increase in their effective efficiency has begun a new direction of research leading to many practical applications. On top of that, diffractive optical elements can not only focus the incident beam, but also can shape the incoming wavefront into a desirable distribution or can redirect the energy. Starting from theoretical calculations of Fourier optics, diffractive elements have been transformed and nowadays form complicated structures that do not resemble a typical Fresnel lens. The precise control over a phase shift introduced by the designed element creates an opportunity to almost freely transform an incident wavefront. Moreover, the vast diversity of computer-generated holograms (also called synthetic) contributes substantially to this topic. Diffractive elements have a great impact on THz optical systems because their manufacturing is very simple in comparison with any other range of radiation (infrared, visible, ultraviolet, etc.). This review paper underlines developments in evolution of diffractive optics and highlights main principles and technological approaches for fabrication of diffraction optics within the terahertz range, thus serving as a guide to design and production considerations.

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The grooved‐dielectric Fresnel zone plate: An effective terahertz lens and antenna

Cited by 33 publications

References 11 publications

State-of-the-art in terahertz sensing for food and water security – A comprehensive review

State-of-the-art in terahertz sensing for food and water security – A comprehensive review

Towards Millimeter-wavelength: Transmission-Mode Fresnel-Zone Plate Lens Antennas using Plastic Material Porosity Control in Homogeneous Medium

Terahertz Diffractive Optics—Smart Control over Radiation

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