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 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 Beam Patterns of the Five-hundred-metre Aperture Spherical Telescope

2013 ◽  
Vol 30 ◽  
Author(s):  
B. Dong ◽  
J. L. Han
Keyword(s):  
Structural Parameters ◽  
Power Level ◽  
Three Dimensional ◽  
High Gain ◽  
Main Beam ◽  
Frequency Range ◽  
Ray Method ◽  
Low Frequencies ◽  
High Frequencies ◽  
Beam Patterns

AbstractThe Five-hundred-metre Aperture Spherical Telescope (FAST) is being constructed in China. With an illuminated aperture of 300-m diameter, it will be the most sensitive single-dish radio telescope in the world. We calculate the beam patterns, gains, and efficiencies of the FAST at 200 MHz, 1.4 GHz, and 3 GHz. A program is developed to calculate the structural parameters and construct the FAST models. The three-dimensional beam patterns are calculated by utilising the shooting and bouncing ray method. We show that, with a coaxial horn feed, the FAST has a beam pattern of high gain and reasonably low first sidelobe over the frequency range of 200 MHz to 3 GHz. Compared with an ideal 300-m parabolic reflector, the un-illuminated spherical part of the FAST would make the power level near both sides of the main beam rise by at least 20 dB and the efficiency tends to decrease at high frequencies. At a zenith angle of 0°, its efficiencies at 200 MHz, 1.4 GHz, and 3 GHz are 71.72%, 66.94%, and 57.55%, respectively. We conclude that the FAST is an excellent telescope at low frequencies. At high frequencies, the triangular spherical panels and the gaps between panels are important factors that affect the performance of the FAST.

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%.

scholarly journals REASERCH ON A WATER-IMMERSED WIDE BAND HORN ANTENNA WITH WATER-FILLED COAXIAL IMPEDANCE MATCHING STRUCTURE

2019 ◽  
Vol 77 ◽  
pp. 115-123 ◽  
Author(s):  
Yang Yang ◽  
Lianghao Guo ◽  
Qing Zhou ◽  
Zhe Wu ◽  
Haibo Jiang ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Wide Band ◽  
Horn Antenna ◽  
Matching Structure

scholarly journals Design and analysis of quad ridged horn antenna for high gain application

2020 ◽  
Vol 1706 ◽  
pp. 012099
Author(s):  
Urvi Barapatre ◽  
Suman Panchal ◽  
Jagdish M Rathod ◽  
P H Panchal ◽  
Kush Parikh
Keyword(s):  
Horn Antenna ◽  
High Gain

Effect of Blowing Agent on Cell Morphology and Acoustic Absorption of Natural Rubber Foam

2015 ◽  
Vol 804 ◽  
pp. 25-29 ◽  
Author(s):  
Wanlop Harnnarongchai ◽  
Kantima Chaochanchaikul
Keyword(s):  
Natural Rubber ◽  
Cell Size ◽  
Cell Morphology ◽  
Foam Cell ◽  
Adsorption Coefficient ◽  
Low Frequencies ◽  
Potassium Oleate ◽  
High Frequencies ◽  
Blowing Agent ◽  
Open Cell Foam

The sound absorbing efficiency of natural rubber (NR) foam is affected by the cell morphology of foam. Potassium oleate (K-oleate) and sodium bicarbonate (NaHCO3) were used as blowing agents to create open-cell foam. Amounts of the blowing agent were varied from 0.5 to 8.0 part per hundred of rubber (phr) to evaluate cell size and number of foam cell as well as sound adsorption coefficient of NR foam. The NR foam specimens were prepared using mould and air-circulating oven for vulcanizing and foaming processes. The results indicated that K-oleate at 2.0 phr and NaHCO3 at 0.5 phr led to form NR foam with the smallest cell size and the largest number of foam cell. At low frequencies, the optimum sound adsorption coefficient of NR foam was caused by filling K-oleate 2 phr. However, that of NR foam at high frequencies was provided by 0.5 phr-NaHCO3 addition.

Hearing loss in diabetics

1993 ◽  
Vol 107 (3) ◽  
pp. 179-182 ◽  
Author(s):  
J. R. Cullen ◽  
M. J. Cinnamond
Keyword(s):  
Hearing Loss ◽  
Sensorineural Deafness ◽  
Insulin Dosage ◽  
Speech Discrimination ◽  
Low Frequencies ◽  
High Frequencies ◽  
History Of ◽  
Insulin Dependent ◽  
Stapedial Reflex ◽  
The Relationship

The relationship between diabetes and senbsorineural hearing loss has been disputed. This study compares 44 insulin-dependent diabetics with 38 age and sex matched controls. All had pure tone and speech audiometry performed, with any diabetics showing sensorineural deafness undergoing stapedial reflecx decat tests. In 14 diabetics stapedial reflex tests showed no tone decay in any patient, but seven showed evidence of recruitment. Analysis of vaiance showed the diabetics to be significantly deafer than the control population.The hearing loss affected high frequencies in both sexes, but also low frequencies in the male. Speech discrimination scores showed no differences. Further analysis by sex showed the males to account for most of the differences. Analysys of the audiograms showered mostly a high tone loss. Finally duration of disbetes, insulin dosage and family history of diabtes were not found to have a significant effect on threshold.

scholarly journals A 60-GHz CPW-Fed High-Gain and Broadband Integrated Horn Antenna

2009 ◽  
Vol 57 (4) ◽  
pp. 1050-1056 ◽  
Author(s):  
Bo Pan ◽  
Yuan Li ◽  
George E. Ponchak ◽  
John Papapolymerou ◽  
Manos M. Tentzeris
Keyword(s):  
Horn Antenna ◽  
High Gain ◽  
60 Ghz
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