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Reflector (antenna)

About: Reflector (antenna) is a research topic. Over the lifetime, 28730 publications have been published within this topic receiving 212618 citations.


Papers
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Proceedings ArticleDOI
01 May 2006
TL;DR: In this article, the authors evaluated the feasibility of developing a large aperture, deployable spherical antenna that meets the needs of NASA science missions requiring large (up to 35-meter) apertures for monitoring earth's atmosphere.
Abstract: Large aperture on-axis antennas for space based and terrestrial applications are of interest to NASA. The NEXRAD in Space (NIS) antenna concept is a large deployable spherical reflector that will provide accurate measurements of the earth’s atmosphere, ocean winds and other environmental parameters at much higher spatial resolutions than currently feasible. This paper presents a study conducted to evaluate the feasibility of developing a large aperture, deployable spherical antenna that meets the needs of NASA science missions requiring large (up to 35-meter) apertures for monitoring earth’s atmosphere. Several conceptual design concepts are considered for this application. The candidate concepts include inflatable reflectors, rigidizable reflectors, hybrid systems, and a deployable electrostatically tensioned reflector. An initial screening of these concepts based on mass, stiffness, and shape controllability was performed. Out of the several design concepts evaluated in this study, the electrostatically figured deployable mesh design concept is proposed as the preferred LDA design. A more detailed evaluation of this concept is performed to address the feasibility of achieving the desired surface shape accuracy using active electrostatic control to correct for on-orbit shape errors introduced by orbital heating. The concept is based on combining a proven lightweight deployable mesh antenna structure and a high precision polymer membrane reflector. The key features of this design are light weight, ability to support active shape control, ability to package well, and the concept is scalable to larger diameters.

51 citations

Journal ArticleDOI
TL;DR: In this paper, a pressure-resistant single tube absorber in front of an involute reflector and covered by highly transparent insulation material was developed for an absorber area of 4.2 m 2 in Freiburg, Germany.

51 citations

Patent
26 Jun 1980
TL;DR: A reflective focussing system comprises two concave reflectors as mentioned in this paper, each reflector is a surface of revolution generated by rotating selected quadratic conic sections about an axis, and the second reflector has its first focus on, or at least centered on, the axis.
Abstract: A reflective focussing system comprises two concave reflectors. Each reflector is a surface of revolution generated by rotating selected quadratic conic sections about an axis. The first reflector has its first focus on the axis and the second reflector has its first focus on, or at least centered on, the axis, and located on the side of the second reflector remote from the first reflector. The second foci of the reflectors are commonly located. Alternative arrangements are disclosed in which the second foci of the two reflectors are not commonly located, but further means is provided to project radiation from the first reflector to the second focus of the second reflector; in which one or both of said foci are rings centered on the axis rather than points; in which adjacent pairs of reflectors are divided into portions, corresponding portions of the pair being confocal, but different portions sharing different common foci; and in which radiation projected from said two reflectors crosses the axis nil, one or a plurality of times.

51 citations

Patent
21 Jan 2010
TL;DR: A surface-emission laser diode includes a GaAs substrate, a cavity region, and upper and lower reflectors provided at a top part and a bottom part of the cavity region.
Abstract: A surface-emission laser diode includes a GaAs substrate, a cavity region, and upper and lower reflectors provided at a top part and a bottom part of the cavity region, the upper reflector and/or the lower reflector including a semiconductor Bragg reflector, at least a part of the semiconductor distributed Bragg reflector includes a semiconductor layer containing Al, Ga and As as major components, there being provided, between the active layer and the semiconductor layer that contains Al, Ga and As as major components, a semiconductor layer containing Al, In and P as major components adjacent to the semiconductor layer that contains Al, Ga and As as major components, with an interface formed coincident to a location of a node of electric strength distribution.

51 citations

Journal ArticleDOI
TL;DR: In this article, a 15 period, wurtzite-structure AlN-GaN reflector stack has been grown on (100) GaAs by gas-source molecular beam epitaxy.
Abstract: A 15 period, wurtzite-structure AlN-GaN reflector stack has been grown on (100) GaAs by gas-source molecular beam epitaxy. A peak reflectance of over 90% has been realised, in agreement with a matrix-method computer simulation. Our results support the feasibility of vertical Fabry-Perot cavity optoelectronics using nitride materials.

51 citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20224
2021567
2020948
20191,159
20181,092
2017977