scholarly journals H-plane horn antenna with enhanced directivity using conformal transformation optics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Eskandari ◽  
Juan Luis Albadalejo-Lijarcio ◽  
Oskar Zetterstrom ◽  
Tomáš Tyc ◽  
Oscar Quevedo-Teruel
Keyword(s):  
Conformal Transformation ◽  
Phase Error ◽  
Three Dimensional ◽  
Physical Space ◽  
Horn Antenna ◽  
High Gain ◽  
Transformation Optics ◽  
Graded Index ◽  
Low Profile ◽  
Dielectric Lens

AbstractConformal transformation optics is employed to enhance an H-plane horn’s directivity by designing a graded-index all-dielectric lens. The transformation is applied so that the phase error at the aperture is gradually eliminated inside the lens, leading to a low-profile high-gain lens antenna. The physical space shape is modified such that singular index values are avoided, and the optical path inside the lens is rescaled to eliminate superluminal regions. A prototype of the lens is fabricated using three-dimensional printing. The measurement results show that the realized gain of an H-plane horn antenna can be improved by 1.5–2.4 dB compared to a reference H-plane horn.

scholarly journals A Novel Miniaturized Four-Ridged Horn Antenna with Enhanced Gain

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yunqing Cao ◽  
Menglong Wang ◽  
Daoyuan Sun ◽  
Dan Shan
Keyword(s):  
Impedance Matching ◽  
Phase Error ◽  
Modern Society ◽  
Horn Antenna ◽  
High Gain ◽  
Side Length ◽  
Laminated Glass ◽  
Glass Cloth ◽  
Low Frequencies ◽  
High Frequencies

Miniaturization of wideband antennas has attracted much attention for its wide application in modern society. This article proposes a novel broadband miniaturized four-ridged horn antenna (FRHA) with high gain operating from 2.6 to 8.4 GHz. By filling the FRHA with the epoxy-laminated glass cloth board, the side length of the aperture realizes 48% reduction comparing to a traditional ridged horn antenna. The cuboid-shaped polyethylene lens provides good impedance matching between the antenna and the air at low frequencies and decreases the aperture phase error at high frequencies, which optimizes the radiating characteristics in the whole operating band.

scholarly journals Three-dimensional quasi-conformal transformation optics through numerical optimization

2016 ◽  
Vol 24 (15) ◽  
pp. 16465 ◽  
Author(s):  
Mateus A. F. C. Junqueira ◽  
Lucas H. Gabrielli ◽  
Felipe Beltrán-Mejía ◽  
Danilo H. Spadoti
Keyword(s):  
Numerical Optimization ◽  
Conformal Transformation ◽  
Three Dimensional ◽  
Transformation Optics

scholarly journals Full three-dimensional isotropic carpet cloak designed by quasi-conformal transformation optics

2017 ◽  
Vol 25 (19) ◽  
pp. 23517 ◽  
Author(s):  
Daniely G. Silva ◽  
Poliane A. Teixeira ◽  
Lucas H. Gabrielli ◽  
Mateus A. F. C. Junqueira ◽  
Danilo H. Spadoti
Keyword(s):  
Conformal Transformation ◽  
Three Dimensional ◽  
Transformation Optics

scholarly journals Boundary integral equation method for resonances in gradient index cavities designed by conformal transformation optics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jung-Wan Ryu ◽  
Jinhang Cho ◽  
Soo-Young Lee ◽  
Yushin Kim ◽  
Sang-Jun Park ◽  
...  
Keyword(s):  
Integral Equation ◽  
Boundary Integral Equation ◽  
Conformal Transformation ◽  
Physical Space ◽  
Integral Equation Method ◽  
Resonant Mode ◽  
Boundary Integral ◽  
Transformation Optics ◽  
Far Field ◽  
Gradient Index

AbstractIn the case of two-dimensional gradient index cavities designed by the conformal transformation optics, we propose a boundary integral equation method for the calculation of resonant mode functions by employing a fictitious space which is reciprocally equivalent to the physical space. Using the Green’s function of the interior region of the uniform index cavity in the fictitious space, resonant mode functions and their far-field distributions in the physical space can be obtained. As a verification, resonant modes in limaçon-shaped transformation cavities were calculated and mode patterns and far-field intensity distributions were compared with those of the same modes obtained from the finite element method.

scholarly journals A novel planar, broadband, high gain lateral wave antenna array for body scanning applications

2020 ◽  
Vol 71 (5) ◽  
pp. 308-316
Author(s):  
Fikret Tokan ◽  
Daniele Cavallo ◽  
Andrea Neto
Keyword(s):  
Critical Role ◽  
Three Dimensional ◽  
High Gain ◽  
Body Scanning ◽  
Lateral Wave ◽  
Directional Radiation ◽  
Wave Antenna ◽  
Public Areas ◽  
Dielectric Lens ◽  
Scanning Systems

Abstract Three-dimensional body scanning systems are increasingly used in sensitive public areas such as airports. By providing a high resolution image of a person from all sides, it is possible to detect potential metallic, ceramic and explosive threats. For these systems, it is essential to design broadband antennas with a fan beam, highly directional radiation in one plane and wide in the other plane, and characterized by phase center stability as a function of frequency. In this paper, the planar lateral wave antenna (LWA) array is proposed to achieve these radiation requirements. The LWA has two critical shortcomings: the flaring part and the dielectric matching layers (MLs), to operate over very broad frequency bands. In this work, these shortcomings are overcomed by forming a connected array of planar LWAs to improve broadband performance and by applying necessary perforations on the dense dielectric lens antenna to create different effective relative permittivity regions. An eight element connected and perforated LWA array is designed to operate in the 8–24 GHz frequency band. The drilled holes are proved to play a similar critical role of MLs in internal reflection suppression. The results emphasize all crucial demands for body scanning systems.

scholarly journals All-metal wideband metasurface for near-field transformation of medium-to-high gain electromagnetic sources

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ali Lalbakhsh ◽  
Muhammad U. Afzal ◽  
Touseef Hayat ◽  
Karu P. Esselle ◽  
Kaushik Mandal
Keyword(s):  
Ray Tracing ◽  
Phase Distribution ◽  
Near Field ◽  
Phase Error ◽  
Metal Structure ◽  
Horn Antenna ◽  
High Gain ◽  
Field Analysis ◽  
Field Phase ◽  
Wide Range

AbstractElectromagnetic (EM) metasurfaces are essential in a wide range of EM engineering applications, from incorporated into antenna designs to separate devices like radome. Near-field manipulators are a class of metasurfaces engineered to tailor an EM source’s radiation patterns by manipulating its near-field components. They can be made of all-dielectric, hybrid, or all-metal materials; however, simultaneously delivering a set of desired specifications by an all-metal structure is more challenging due to limitations of a substrate-less configuration. The existing near-field phase manipulators have at least one of the following limitations; expensive dielectric-based prototyping, subject to ray tracing approximation and conditions, narrowband performance, costly manufacturing, and polarization dependence. In contrast, we propose an all-metal wideband phase correcting structure (AWPCS) with none of these limitations and is designed based on the relative phase error extracted by post-processing the actual near-field distributions of any EM sources. Hence, it is applicable to any antennas, including those that cannot be accurately analyzed with ray-tracing, particularly for near-field analysis. To experimentally verify the wideband performance of the AWPCS, a shortened horn antenna with a large apex angle and a non-uniform near-field phase distribution is used as an EM source for the AWPCS. The measured results verify a significant improvement in the antenna’s aperture phase distribution in a large frequency band of 25%.

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