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.

Earth station antenna system

Abstract: A small aperture satellite ground station communications antenna is disclosed. A rectangular section of a curved parabolic reflector is provided having first and second rectangular dimensions. An azimuth elevation pedestal for positioning the reflector is provided such that the antenna bore sight is aligned with a geostationary satellite. The reflector is supported by the pedestal to permit rotation of the reflector about a third polarization axis for the antenna. The rotation along the polarization axis permits the reflector to be optimally positioned such that its long dimension is aligned with an orbital arc of a geostationary satellite. Angle scales are provided on all three axes to facilitate repositioning to other satellites based on an initial satellite location, which serves as a reference for the scales.

Microcontroller-Based Two-Axis Solar Tracking System

Abstract: The main goal of this project is to develop and implement a prototype of two-axis solar tracking system based on a PIC microcontroller. The parabolic reflector or parabolic dish is constructed around two feed diameter to capture the sun's energy. The focus of the parabolic reflector is theoretically calculated down to an infinitesimally small point to get extremely high temperature. This two axis auto-tracking system has also been constructed using PIC 16F84A microcontroller. The assembly programming language is used to interface the PIC with two-axis solar tracking system. The temperature at the focus of the parabolic reflector is measured with temperature probes. This auto-tracking system is controlled with two 12V, 6W DC gear box motors. The five light sensors (LDR) are used to track the sun and to start the operation (Day/Night operation). Time Delays are used for stepping the motor and reaching the original position of the reflector. The two-axis solar tracking system is constructed with both hardware and software implementations. The designs of the gear and the parabolic reflector are carefully considered and precisely calculated.

Efficient directional spontaneous emission from an InGaAs/InP heterostructure with an integral parabolic reflector

Abstract: In order to increase the radiative efficiency and directivity of spontaneous emission from a lattice-matched InGaAs/InP heterostructure, we have polished the substrate into a parabolic reflector. We combine optical and thermal measurements to obtain the absolute external efficiency over a wide range of carrier densities. Using a simple model, the measurement is used to determine interface, radiative, and Auger recombination rates in the active material. At the optimal density, the quantum efficiency exceeds 60% at room temperature. The divergence of the emitted light is less than 20°. In fact, the beam profile is dominated by a 6° wide lobe that can be swept across the field of emission by changing the excitation position. This suggests a way to create an all-electronic scanned light beam.