Cassegrain antenna

About: Cassegrain antenna is a research topic. Over the lifetime, 3207 publications have been published within this topic receiving 28278 citations.

Dielectric EBG Corner Reflector Antenna

Abstract: In this paper, we present a novel dielectric EBG corner reflector antenna The reflector is realized using dielectric rods arranged in a square lattice The influence of reflector width, length and source distance from the corner apex is investigated using a simple two-dimensional antenna model; results are then used to design a threedimensional antenna A prototype was build and tested, showing a good agreement between simulations and measurements results: 40% impedance bandwidth is achieved as well as stable radiation patterns with a maximum gain of 135 dBi and a front-to-back-ratio greater than 20 dB

Reflector antenna for operation in more than one frequency band

Abstract: A reflector antenna is constructed for operation in at least two frequency ranges. For this purpose the concave surface of the antenna reflector body, which preferably has a paraboloid configuration, is provided with surface zones arranged in regular arrays or patterns. These surface zones provide antenna or reflector elements which are reflecting or transparent with regard to a particular frequency range or band width, while other surface zones of the antenna reflector surface are transparent or reflecting in another given frequency range or band widths. Thus, depending on the configurations and dimensions of these different surface zones one and the same antenna is capable of handling frequencies in a plurality of different band widths and different apertures.

Offset parabolic reflector antenna

Abstract: In accordance with the disclosure, two or more main beams of an offset parabolic reflector antenna are directed without producing second order aberrations by placing their respective feeds so that their phase centers reside at mathematically defined locations.

The Application of the Cassegrainian Principle to Ground Antennas for Space Communications

Abstract: In the last few years considerable interest has arisen in application of the Cassegrainian principle to paraboloidal antenna systems. In the case of large ground-based tracking antennas, it appears that this type of feed system can offer significant performance and operational advantages over conventional systems. For this application, however, special sidelobe requirements are imposed on the Cassegrainian system. The forward sidelobe distribution must be controlled to reduce the effect of solar noise interference, and the backlobe level must be controlled to reject blackbody radiation from the antenna environment. It is shown that these considerations are the major factor in choosing the feed system configuration. An experimental system utilizing an 85-ft antenna operating at 960 Mc is described. This system has an aperture efficiency of approximately 50 per cent and a measured zenith noise temperature of 9.5° K.

Peak gain of a Cassegrain antenna with secondary position adjustment

Abstract: For an enclosed Cassegrain antenna, the loss of peak gain and beam deviation due to structural deformations of the primary reflector and rigid body displacements of the secondary reflector and of the feed are computed from the combined changes in the radio frequency (RF) path length. As the antenna moves in elevation, the position of the secondary reflector may be adjusted mechanically to minimize the loss of peak gain; a general method for the computation of the magnitude of such adjustments and of their effects on the gain and pointing of the system is presented. Numerical results are obtained for a particular case of a 45-ft diameter antenna designed for operation at 95.5 GHz RF for which the computed peak gain of the antenna varies significantly with the elevation angle. The results indicate that the loss of peak gain as the antenna moves in elevation can be substantially reduced by mechanical adjustment of the position of the secondary reflector.