A note on the shaping of dual reflector antennas
TL;DR: In this article, a technique based on a recent paper for designing shaped dual reflector antennas that appears to be significantly better than the traditional method is presented, the main advantages derived are extreme computational simplicity and the ability to utilize very accurate feed pattern expressions.
Abstract: A technique based on a recent paper [3] for designing shaped dual reflector antennas that appears to be significantly better than the traditional method [1], [2] is presented. The main advantages derived are extreme computational simplicity and the ability to utilize very accurate feed pattern expressions. A typical practical problem is solved using [1] and our method to bring out these features.
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TL;DR: An X-band 8.5ft brassboard antenna system was designed and developed which required a 70% total antenna efficiency and a 25 dB isolation between the circularly polarized transmit and receive ports.
Abstract: An X-band 8.5-ft brassboard antenna system was designed and developed which required a 70% total antenna efficiency and a 25 dB isolation between the circularly polarized transmit and receive ports. To maximize the aperture efficiency, a shaping technique was used to generate a specially contoured subreflector and main reflector. To reduce cost, a configuration was chosen such that the shaped main reflector could be matched with negligible phase error using a commercially available paraboloid. The antenna gain of this shaped system with an electrically small subreflector (10.7 lambda ) is 0.75 dB higher than that of a conventional system using the same paraboloid and a matching hyperbolic subreflector. Measured results demonstrated that even for a small system the antenna performance can be appreciably improved at low cost by using a shaped subreflector. >
4 citations
13 Dec 2012
TL;DR: A strategy to optimize dual-reflector antennas for compact Satellite Communications (SATCOM) terminals to meet various user-specified requirements is described and an overview of the method and design methodology is given.
Abstract: A strategy to optimize dual-reflector antennas for compact Satellite Communications (SATCOM) terminals to meet various user-specified requirements is described. An overview of the method and design methodology is given, and some of the challenges in designing compact antennas as compared to traditional large Earth Station antennas are described.
2 citations
TL;DR: In this article, a technique based on a recent paper for designing shaped dual reflector antennas that appears to be significantly better than the traditional method [I], [2] is presented.
Abstract: Abstruct-A technique based on a recent paper [3] for designing shaped dual reflector antennas that appears to be significantly better than the traditional method [I], [2] is presented. The main advantages derived are extreme computational simplicity and the ability to utilize very accurate feed pattern expressions. A typical practical problem is solved using [l] and our method to bring out these features. The analytical procedure for determining the reflector profiles in a symmetrical-shaped dual reflector antenna system based on ray optics is very well known [ 1 1 , [ 2 ]. Here we present a computationally efficient approach based on a paper by Lee et al. [ 3 ]. The approach is efficient because the new scheme involves a single first-order differential equation rather than the coupled differential equations of the earlier scheme. The method outlined also provides certain significant advantages. The geometry of the subreflector and main reflector is shown in Fig.
1 citations
25 Jun 1984
17 Jun 1985
References
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01 Jul 1963
TL;DR: In this paper, a generalization of the optical design is presented which allows the synthesis of reflector shapes for arbitrary phase and amplitude distributions in the aperture of the larger reflector with an arbitrary primary feed.
Abstract: Conventional dual reflector antenna systems have been based largely on the Cassegrain parabola-hyperbola design or the Gregorian parabola-ellipse design[1]. The designs are based on the principles of geometrical optics with consequent limitations. A generalization of the optical design is presented here which allows the synthesis of reflector shapes for arbitrary phase and amplitude distributions in the aperture of the larger reflector with an arbitrary primary feed. In contrast, a single reflector design permits either phase or amplitude control in the aperture. The analysis will be made for a surface of revolution and results presented for a uniform phase and amplitude case.
194 citations
01 Jan 1975
TL;DR: In this paper, the geometrical theory of diffraction and its application for thin-wire elements and arrays is discussed. But the authors focus on the application of the method of moments to thin-wires and arrays.
Abstract: Applications of the method of moments to thin-wire elements and arrays.- Characteristic modes for antennas and scatterers.- Some computational aspects of thin-wire modeling.- Stability and convergence of moment method solutions.- The geometrical theory of diffraction and its application.- Reflector antennas.
124 citations
Journal Article•
51 citations
TL;DR: In this paper, a geometric shaping scheme based on geometric optics for offset-fed dual-reflector antennas is presented, which transforms a ray tube emerging from a symmetric feed horn into a circular beam with a uniform phase and a prescribed radial power distribution on the aperture.
Abstract: A shaping scheme based on geometric optics for offset-fed dual-reflector antennas is presented. A ray tube emerging from a symmetric feed horn is transformed, after reflections, into a circular beam with a uniform phase and a prescribed radial power distribution on the aperture. In this scheme, Snell's law was not imposed on the main reflector. Based on this approximate solution, computer runs were taken for a 5.5-m dish baseline system, and very satisfactory results were obtained. The system so designed not only gives very low sidelobes but also provides a very high aperture efficiency. At 12 GHz an estimated 84 percent of aperture efficiency was achieved in spite of the severe constraint that the ray intersecting the edge of the main reflector meet a -10-dBi criterion.
49 citations