Topic
Parabolic reflector
About: Parabolic reflector is a research topic. Over the lifetime, 3375 publications have been published within this topic receiving 30735 citations. The topic is also known as: paraboloid reflector & paraboloidal reflector.
Papers published on a yearly basis
Papers
More filters
24 May 1982
TL;DR: In this article, a Fourier-Bessel series technique was developed to investigate the far-field pattern and focal region distribution of reflector antennas under wide-angle scanning, where the current on the reflector surface is first expanded in terms of elementary sinusoidal functions via the well established fast Fourier transform (FFT) algorithm and the surface integration involved in physical optics integration is then carried out analytically.
Abstract: A new numerical method, Fourier-Bessel series techniques, has been developed to investigate the far-field pattern and focal region distribution of reflector antennas under wide-angle scanning. In this Fourier-Bessel series technique, the current on the reflector surface is first expanded in terms of elementary sinusoidal functions via the well established fast Fourier transform (FFT) algorithm and the surface integration involved in physical optics integration is then carried out analytically. The derivation of Fourier-Bessel series and its convergence as applied to parabolic reflectors are described. The secondary patterns and focal region distributions of a parabolic reflector with F/D = 0.48 and scanning up to 48 beamwidths are presented.
39 citations
Patent•
23 Jan 2004
TL;DR: In this paper, a catadioptric light distribution system is proposed to collect and collimate the hemispherical pattern of light emitted by a Lambertian light emitting diode (LED) into a collimated beam directed essentially parallel to the optical axis of the LED.
Abstract: A Catadioptric Light Distribution System is disclosed. The system collects and collimates the hemispherical pattern of light emitted by a Lambertian light emitting diode (LED) into a collimated beam directed essentially parallel to the optical axis of the LED. The system comprises a circular condensing lens having a center axis that is aligned with the optical axis of the LED and which is configured to receive an collimate a portion of the light from the LED defined by a central cone of light centered around the optical axis. A parabolic reflector having circular opening formed therethrough is centered on the center axis of the parabolic reflector and is positioned around the LED to receive and redirect the light which does not form the cone that impinges upon the condensing lens in a collimated annular beam in a direction away from the condensing lens. The light reflected and culminated by the parabolic reflector is directed onto a circular annular double bounce mirror which is configured and positioned to receive the annular beam from the parabolic reflector and reflect that beam of light 180° so that it is collimated in an annular beam which passes around the edge of the condensing lens. Thus, substantially all the light emitted by the LED is culminated into a beam of light that is substantially parallel to the optical axis of the LED by either the condensing lens or by the combination of the parabolic reflector and the double bounce mirror.
38 citations
Patent•
20 Dec 1990
TL;DR: An Orthogonal Parabolic Reflector (40) is generated by rotating a parabolic curve 90° to the axis of symmetry passing through the focal point (42) of the parabola as discussed by the authors.
Abstract: An Orthogonal Parabolic Reflector (40) is generated by rotating a parabolic curve 90° to the axis of symmetry passing through the focal point (42) of the parabola. The Orthogonal Parabolic Reflector (40) can concentrate a section of the linear source or sink (41) on the axis of rotation to the focal point (42), resulting in integrating the intensity as a point source or sink at the focal point (42) with almost no physical dimension effects.
38 citations
TL;DR: A novel passive focusing system for Air-Coupled Ultrasonic (ACU) piezoelectric transducers which is inspired by the Newtonian-Cassegrain telescope concept, which has a coaxial design, which eases the transducers positioning and use in many applications, and is less bulky than off-axis mirrors.
38 citations
TL;DR: In this article, an investigation of light scattering from a beam projected into the atmosphere over New Mexico was made by means of the searchlight technique, where a 60-in. parabolic mirror and photomultiplier tube mounted at its focus comprised the sensing device.
Abstract: : An investigation of light scattering from a beam projected into the atmosphere over New Mexico was made by means of the searchlight technique. Modulation of the searchlight beam was necessary in order to differentiate the scattered light from the light of the night sky. Therefore, a modulating technique using a rotating beam is first developed and evaluated, as is the shutter method of modulation used for acquisition of final upper-altitude data. A 60-in. parabolic mirror and photomultiplier tube mounted at its focus comprised the sensing device. A narrow-band tunable amplifier then selected the desired signal component from the photomultiplier output. Absolute values of atmospheric densities were obtained by assuming Rayleigh scattering and matching the measured response at 15 km with the densities obtained from radiosonde measurements at the same height. Eight vertical density distributions to 61.8 km so determined were in good agreement with the Rand distribution for a model atmosphere. A seasonal trend for densities at high altitudes was evident. (Author)
38 citations