Journal ArticleDOI
Dual offset reflectors shaped for zero cross-polarisation and prescribed aperture illumination
B S Westcott,F. Brickell +1 more
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In this article, the problem of shaping dual offset reflectors, fed by a linearly polarised rotationally symmetric feed horn, to produce a parallel beam over a non-circular aperture with zero cross-polarisation was considered under the assumptions of geometrical optics.Abstract:
The problem of shaping dual offset reflectors, fed by a linearly polarised rotationally symmetric feed horn, to produce a parallel beam over a non-circular aperture with zero cross-polarisation, is considered under the assumptions of geometrical optics. The condition for zero cross-polarisation leads to a partial differential equation, which hitherto has been solved numerically, but is shown here to possess an analytical solution. For uniqueness an additional constraint is put on systems with a plane of symmetry by prescribing the power distribution along the aperture line of symmetry. A suitable choice yields a uniform aperture edge illumination.read more
Citations
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Journal ArticleDOI
A first-order treatment of aberrations in Cassegrainian and Gregorian antennas
TL;DR: In this paper, the decrease in aperture efficiency caused by small aberrations in a reflector antenna is determined, and conditions that optimize performance are given for the design of multibeam antennas in ground stations and satellites.
Journal ArticleDOI
First-order correction of aberrations in Cassegrainian and Gregorian antennas
TL;DR: In this article, the deformation coefficients of the reflectors for small feed displacements were derived for a multibeam ground station and satellite antennas, and the deformations required to correct astigmatism, if the antenna aperture is not centered is also derived.
Inverse methods for illumination optics
TL;DR: The final author version and the galley proof are versions of the publication after peer review that features the final layout of the paper including the volume, issue and page numbers.
Comparison of Designs of Off-Axis Gregorian Telescopes for Millimeter-Wave Large Focal-Plane Arrays
Shaul Hanany,Daniel P. Marrone +1 more
TL;DR: The design that cancels both coma and astigmatism provides the largest flat FOV, approximately 21 square deg, and the FOV can be increased by approximately 15% by means of optimizing the shape and location of the focal surface.
Journal ArticleDOI
Comparison of designs of off-axis Gregorian telescopes for millimeter-wave large focal-plane arrays
Shaul Hanany,Daniel P. Marrone +1 more
TL;DR: In this article, the authors compared the diffraction-limited field of view (FOV) provided by four types of off-axis Gregorian telescopes: the classical Gregorian, the aplanatic Gregorian and the designs that cancel astigmatism and both astigmatisms and coma.
References
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Journal ArticleDOI
The definition of cross polarization
TL;DR: There are at least three different definitions of cross polarization used in the literature, and the definition which corresponds to one standard measurement practice is proposed as the best choice.
Journal ArticleDOI
The geometrical optics design of reflectors using complex coordinates
TL;DR: In this paper, the mathematics of reflector design under the geometrical optics approximation is treated using complex coordinates, where conformal transformations occur naturally in the new formalism and their application to reflector designs appears to have great potential.
Journal ArticleDOI
Phase and power density distributions on plane apertures of reflector antennas
F. Brickell,B S Westcott +1 more
TL;DR: In this article, the synthesis of a dual reflector system to produce given aperture phase and power distributions when illuminated by a point source of prescribed power density is shown to depend on the solution of a particular partial differential equation of the Monge-Ampere type.
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Phase and power density distributions on plane apertures of reflector antennas
F. Brickell,B S Westcott +1 more