Topic
Reflector (antenna)
About: Reflector (antenna) is a research topic. Over the lifetime, 28730 publications have been published within this topic receiving 212618 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, the effect of wall resistance on the operation of the cavity is studied; as the frequency of the radiation is increased to near 250 GHz, wall heating severely limits the average power rating of whispering-gallery devices.
Abstract: High Q Bragg resonators are studied for application to millimeter wave CARM oscillators driven by electron beams with power greater than 100 MW. ‘Whispering-gallery’ modes are shown to have the highest Q. The two effects that cause reflections, impedance mismatch owing to variations in the wall radius and currents driven in the walls of the reflector sections, are shown to compete, paving the way for anomalously low Qs for some of the other modes. The effect of wall resistance on the operation of the cavity is studied; as the frequency of the radiation is increased to near 250 GHz, wall heating severely limits the average power rating of whispering-gallery devices.
42 citations
Patent•
20 May 1985
TL;DR: In this paper, a plurality of angularly spaced rotating arms extending from a central axis are used for scanning radiation over a surface, where a central reflector is positioned at the axis of the arms and a radially remote reflector on each arm for folding an optical radiation path toward the object to be scanned.
Abstract: Optical apparatus for scanning radiation over a surface includes a plurality of angularly spaced rotating arms extending from a central axis. A central reflector is positioned at the axis of the arms and a radially remote reflector is positioned on each arm for folding an optical radiation path toward the object to be scanned. The central reflector rotates with the arms but is sequentially indexed into optical path alignment with each radially remote reflector so that a beam of radiation in the optical path is scanned over the same predetermined arcuate segment by each of the remote reflectors.
42 citations
Patent•
03 Aug 1978TL;DR: In this paper, a mirror glass plate is used as a reflector for solar collectors, which is adhesively bonded with its mirrored side on a supporting body, and in particular a honeycomb support body.
Abstract: Reflector for solar collectors consisting of a mirror glass plate (23). To minimize the absorbed radiation energy through the glass plate, a thin glass plate is provided, the plate strength is below that required for a self-supporting glass plate glass thickness. This glass plate is adhesively bonded with its mirrored side on a supporting body (22), and in particular a honeycomb support body.
42 citations
TL;DR: In this article, an electron reflector is proposed to improve the open-circuit voltage of CdTe solar cells, which can effectively reduce electron recombination at the back surface.
Abstract: The incorporation of an electron reflector is a proposed strategy to improve the open-circuit voltage of CdTe solar cells. An electron reflector is a conduction-band barrier that can effectively reduce electron recombination at the back surface. In this work, the electron-reflector strategy is numerically applied to a thin-film CdTe record-cell baseline model (efficiency = 16.5%). Simulation shows that to have the optimal effect from an electron reflector, the CdTe thickness should be on the order of 1 µm, or slightly lower if the optical reflection at the back surface can be enhanced. Efficiency above 19% should be achievable with a 0.2-eV electron reflector and currently achievable parameters (1014-cm−3 hole density and 1-ns lifetime). Moreover, efficiency above 20% should be possible at a 1-µm absorber layer if large optical back reflection can also be achieved. Copyright © 2011 John Wiley & Sons, Ltd.
42 citations
Posted Content•
TL;DR: This work introduces purely local reflective metasurfaces for arbitrary manipulations of the power distribution of reflected waves without excitation of any auxiliary evanescent field and finds that these power-conformal metamirrors can be easily implemented with conventional passive unit cells.
Abstract: Recently, the complexity behind manipulations of reflected fields by metasurfaces has been addressed showing that, even in the simplest scenarios, non-local response and excitation of auxiliary evanescent fields are required for perfect field control. Although these solutions theoretically allow to reflect incident plane waves into any desired direction, actual implementations are difficult and, in most cases, require extensive numerical optimization of the metamirror topology. In this work we introduce purely local reflective metasurfaces for arbitrary manipulations of the power distribution of reflected waves without excitation of any auxiliary evanescent fields. The reflected fields of such local metamirror contain only the desired propagating waves. The method is based on the analysis of the power flow distribution and the adaptation of the reflector shape to the desired distribution of incident and reflected fields. As a result, we find that these power-conformal metamirrors can be easily implemented with conventional passive unit cells.The results can be used for the design of reflecting surfaces with multiple functionalities and for waves of different physical nature. In this work, we present the cases of anomalous reflection and beam splitting, both for acoustic and electromagnetic waves.
42 citations