Cassegrain antenna

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

Multi-band antenna system for satellite communications

Abstract: The present invention provides an improved single antenna system that allows reception of RF energy at multiple frequencies. In one embodiment, the antenna is implemented as a multi-beam, multi-feed antenna having a primary reflector fitted with a dual mode feed tube and a switchable LNB that supports both Ka band and Ku band reception. In another embodiment, the antenna is implemented as a multi-beam, multi-feed antenna having a primary reflector fitted with a feed horn and a LNB that is capable of providing movement such that the feed horn with the LNB is at a focal point with the primary reflector for both Ka and Ku band reception. In another embodiment, the antennae is implemented as a multi-beam, multi-feed antenna having a primary reflected fitted with a feed horn assembly and a switchable LNB that supports both Ka band and Ku band reception.

Offset-parabolic-reflector antennas: A review

Abstract: Although used for some decades, the offset-parabolicreflector antenna's electrical properties and performance were not accurately modeled and optimized until the 1960's. This paper reviews, in a tutorial fashion, the state of the art of this important antenna for readers who are not necessarily experts in antenna theory and technology. After a discussion of fundamentals, the performances of both single- and double-reflector configurations are treated and compared, and practical primary feeds are described. Comments are given on the present status of analysis and design and on problems to be solved.

Design of dual-reflector antennas with arbitrary phase and amplitude distributions

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.

Microwave antennas derived from the cassegrain telescope

Abstract: A microwave antenna can be designed in the form of two reflecting dishes and a feed, based on the principle of the Cassegrain optical telescope. There are a variety of shapes and sizes available, all described by the same set of equations. The essential performance of a Cassegrain double-reflector system may be easily analyzed by means of the equivalent-parabola single-reflector concept. Techniques are available for reducing the aperture blocking by the sub dish of the Cassegraln system: one method minimizes the blocking by optimizing the geometry of the feed and sub dish; other methods avoid the blocking by means of polarization-twisting schemes. The former method yields good performance in a simple Cassegrain antenna when the beamwidth is about 1\deg or less. The latter methods are available for any application not requiring polarization diversity, and an optimized set of polarization-operative surfaces has been developed for these twisting Cassegrain antennas. Experimental results, presented for practical antennas of both types, illustrate the feasibility of these principles. A number of unusual benefits have been obtained in the various Cassegrain antenna designs, and additional interesting features remain to be exploited.

Reflector antenna and method of producing a sub-reflector

Abstract: A reflector antenna is disclosed with a main reflector and a rotatable sub-reflector that significantly reduces vibrations in the sub-reflector. The sub-reflector includes a reflecting surface located in front of the main reflector between the main reflector and a radiation source as well as a cylindrical shaft that extends in a direction parallel to a main axis of the main reflector. The sub-reflector is made of two connected parts, wherein one part includes the reflecting surface, and the other part is made of a non-reflecting material and formfittingly engages with the reflecting surface. The sub-reflector is rotatably supported on the cylindrical shaft and has a rotation speed of between approximately 1500 to 3500 rpm.