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.

Method and system for positioning an apparatus for monitoring a parabolic reflector aerially

Abstract: The invention relates to a method and a system for positioning an apparatus (10) for monitoring a parameter of one or more parabolic reflectors (15) of a solar thermal field (122), wherein the method comprises positioning the apparatus (10) at a first field location (105) responsive to the position of said respective parabolic reflector (15), acquiring information of an absorber tube (38) of said respective parabolic reflector (15), and positioning the apparatus (10) at the second field location (110) responsive to the information of the absorber tube (38), the second field location (110) being beyond the focus of said respective parabolic reflector (15).

Wide angle warning light

Abstract: A dual emitter light assembly employs a reflector having a pair of concave reflector dishes. Each dish is associated with a lamp socket. Each concave dish comprises at least three parabolic reflector surfaces having a common focal point. The axes of the parabolas of revolution which define the reflector surfaces are non-parallel and lie in a common plane, the axis of both dishes lying in the same plane.

Comparison of induced current and aperture field integrations for an offset parabolic reflector

Abstract: The fields predicted by integration of the physical optics induced currents on the reflector (ICM) and the geometrical optics aperture fields (AFM) on the surface that caps the reflector are compared numerically for offset parabolic reflectors. It is found that the AFM solutions are very close to ICM solutions for the main beam and the first few sidelobes but discrepancy remains for the far-out sidelobes. This discrepancy is found to come mainly from the difference of polarization matrix for each method.

A Novel Beam Squint Compensation Technique for Circularly Polarized Conic-Section Reflector Antennas

Abstract: Beam squint generally exists in offset reflector antennas with circularly polarized feeds. It is manifested by a small beam shift of the radiation pattern in the plane perpendicular to the principal offset plane, which can significantly affect the beam pointing accuracy. In this paper a practical and widely applicable compensation technique for the beam squint is proposed. Simulation results show that a small lateral feed displacement in the perpendicular plane can effectively minimize or eliminate the linear phase shift caused by the depolarization effect, thus compensating for the beam squint effect. This is in practice very useful for offset reflector antennas where the previously suggested method based on feed tilting may not be proper. A simple formula is derived to quickly estimate the optimal feed displacement for both right- and left-hand circularly polarized feeds. Three representative examples: a single offset parabolic reflector, a suboptimal offset Cassegrain reflector, and an axially symmetric Cassegrain reflector with an off-focus feed, are presented to validate the proposed method. Satisfactory results are achieved for all three examples.

Evaluation of focal fields and radiation characteristics of a dual-offset reflector antenna

Abstract: A receive-mode analysis of a dual-offset reflector antenna consisting of an offset paraboloid and an offset hyperboloid is presented. In this analysis the field scattered from the offset paraboloid is determined using a g.t.d. formulation involving two edge points and a reflection point, if one exists. A method is described for deciding whether there is a reflection point from the gradient of the path length at the edge points. The focal-region fields and the radiation characteristics are computed by numerical integration of the physical optics current on the offset hyperboloid. An experimental antenna operating at 35 GHz is described Results of measurements of radiation patterns and of the power coupled into a circular waveguide array feed are compared with theory. In each cae reasonable agreement is achieved for copolarised directed components. However, the experimental antenna produced higher crosspolarisation than expected.