Topic
Reflector (antenna)
About: Reflector (antenna) is a research topic. Over the lifetime, 28730 publications have been published within this topic receiving 212618 citations.
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Patent•
02 Jul 2013
TL;DR: In this paper, a recessed light fixture includes an LED module, which includes a single LED package that is configured to generate all light emitted by the recessed lighting fixture, and an optic coupler can be coupled to the reflector housing and configured to cover electrical connections at the substrate.
Abstract: A recessed light fixture includes an LED module, which includes a single LED package that is configured to generate all light emitted by the recessed light fixture. For example, the LED package can include multiple LEDs mounted to a common substrate. The LED package can be coupled to a heat sink for dissipating heat from the LEDs. The heat sink can include a core member. A reflector housing may be coupled to the heat sink and configured to receive a reflector. The reflector can have any geometry, such as a bell-shaped geometry including two radii of curvature that join together at an inflection point. An optic coupler can be coupled to the reflector housing and configured to cover electrical connections at the substrate and to guide light emitted by the LED package.
44 citations
TL;DR: In this article, it was shown that even a column which is very narrow compared with a wave-length will reflect as efficiently as a metal strip with a width comparable to a wavelength, and that strong reflexion is a resonance effect, and will be damped if the electron collision frequency is not small enough.
Abstract: A THEORETICAL discussion by Herlofson1 shows that a narrow ionized column—such as a meteor trail—will be a particularly good reflector for radio waves of frequency ν if the electric vector in the waves is perpendicular to the axis of the column, and the electron density is approximately equal to (Mr. Herlofson informs me that his note in The Observatory is not correct; in particular, resonance will occur for values of e near − 1 instead of 0. A revised theory will be published elsewhere.) In this case, even a column which is very narrow compared with a wave-length will reflect as efficiently as a metal strip with a width comparable to a wavelength. The strong reflexion is a resonance effect, and will be damped if the electron collision frequency is not small enough.
44 citations
Patent•
01 Sep 1989
TL;DR: In this article, a Yagi-Uda-type antenna includes also a sleeve embracing the dipole, which is a closed cylindrical element surrounding a dipole and a pair of discrete elements forming an open sleeve.
Abstract: This Yagi-Uda-type antenna includes also a sleeve embracing the dipole. The sleeve may be a closed cylindrical element surrounding the dipole or it may comprise a pair of discrete elements forming an "open sleeve". The dipole, sleeve, reflector, and director elements may be in filamentary form, or they may be fabricated from stripline.
44 citations
TL;DR: In this article, the authors analyzed the resolution of imaging functionals that migrate the cross-correlation matrices of passive sensor arrays in a homogeneous medium and showed that the resolution depends on the sensor array diameter, the distance from the array to the reflector and the central frequency.
Abstract: We analyze the resolution of imaging functionals that migrate the cross-correlation matrices of passive sensor arrays. These matrices are obtained by cross-correlating signals emitted by ambient noise sources and recorded by the passive sensor array. They contain information about reflectors in the surrounding medium. Therefore, travel time or Kirchhoff migration of the cross-correlations can, under favorable circumstances, produce images of such reflectors. However, migration should be carried out appropriately depending on the type of illumination provided by the ambient noise sources. We present here a detailed resolution analysis of these functionals in a homogeneous medium. Resolution depends on the sensor array diameter, the distance from the array to the reflector and the central frequency, as is the case in active array imaging. When imaging with passive sensor arrays and ambient noise, resolution also depends on the space and time coherence of the noise sources because it determines an effective noise bandwidth.
44 citations
Patent•
21 Jan 2016TL;DR: In this article, the authors described the methods and configurations for an efficient collection of fluorescence emitted by the nitrogen vacancies of a diamond of a DNV sensor, including a diamond having a nitrogen vacancy and a reflector positioned about the diamond to reflect a portion of light emitted from the diamond.
Abstract: Methods and configurations are disclosed for an efficient collection of fluorescence emitted by the nitrogen vacancies of a diamond of a DNV sensor. Some implementations may include a diamond having a nitrogen vacancy and a reflector positioned about the diamond to reflect a portion of light emitted from the diamond. In some implementations the reflector may be parabolic or ellipsoidal. In some implementations, DNV sensor may have a reflector and a concentrator. Other implementations may include a diamond with a nitrogen vacancy and a reflector positioned about the diamond to reflect a portion of light emitted from the diamond using a dielectric mirror film applied to the reflector. Still other implementations may have a diamond with a nitrogen vacancy and a dielectric mirror film coated on the diamond.
44 citations