Topic
Reflector (antenna)
About: Reflector (antenna) is a research topic. Over the lifetime, 28730 publications have been published within this topic receiving 212618 citations.
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Patent•
23 Nov 1987
TL;DR: In this paper, a steerable beam antenna system for use in satellite communication systems and including a main reflector and an antenna array having a plurality of feed elements is disclosed, where the antenna array is positionable at or near at least one focal point of the primary reflector.
Abstract: A steerable beam antenna system for use in satellite communication systems and including a main reflector and an antenna array having a plurality of feed elements is disclosed. The antenna array is positionable at or near at least one focal point of the main reflector, and its feed elements can receive microwaves from or transmit microwaves toward the main reflector. A Butler matrix having multiple input ports and multiple outputs is connected to the array of feed elements and substantially performs a spatial Fourier transformation on a generated set of signals to be transmitted which have a predetermined phase relationship between the signals, which is necessary to create the steerable beam. The Butler matrix also can perform an inverse spatial transformation on a set of incoming signals focused on the array by the reflector and received by the feed elements. By using a Butler matrix, the antenna system of the present invention is able to communicate with multiple ground stations simultaneously and with high gain using many virtual spot beams, each oriented to a distinct location on the earth that is dependent on the relative frequency of the beam.
63 citations
Patent•
14 Jan 1994TL;DR: In this article, an improved interferometric measuring system was proposed, where the system projects a first beam of light at a first measurement wavelength along a reference path to a reference reflector and a second beam at a second measurement wavelength to a measurement reflector.
Abstract: An improved interferometric measuring system wherein the system projects a first beam of light at a first measurement wavelength along a reference path to a reference reflector and a second beam of light at a second measurement wavelength along a measurement path to a measurement reflector, and determines a change in position of the measurement reflector from an interference pattern produced between a first light beam reflected from the reference reflector and a second light beam reflected from the measurement reflector, and wherein the system can measure atmospheric disturbances along the measurement path, concurrently with measuring a change in the position of the measurement reflector.
63 citations
Patent•
16 Nov 1985
TL;DR: In this article, the primary and secondary reflectors of each radiation reception zone are combined to form a further structural unit which is arranged in a predetermined spaced relationship to the first compact structural unit.
Abstract: An infrared intrusion detector having a predetermined number of rows of radiation reception zones comprises a primary reflector and a secondary reflector for each row of radiation reception zones. The primary reflectors and their associated secondary reflectors form a folded radiation path. The folded radiation path allows for compact construction and simple manufacturing of the infrared intrusion detector. One reflector of each radiation reception zone forms together with the infrared sensor a compact structural unit. The other reflectors of each radiation reception zone are combined to form a further structural unit which is arranged in a predetermined spaced relationship to the first compact structural unit. In order to achieve uniform detection sensitivity in radiation reception zones having different angles of inclination to the horizontal plane, a larger focal length is chosen for radiation reception zones with smaller angles of inclination and longer range. Likewise, to achieve uniform detection sensitivity even with oblique infrared radiation impingement, the surface area of the primary reflectors increases within each horizontal row from the middle to the sides.
63 citations
Patent•
04 Jun 2003
TL;DR: In this article, an assembly for receiving and transmitting millimeter (mm) waves, including at least one mm wave reflector (84, 86, 88) and at least 1 mm transmission wave feed (72), was presented.
Abstract: An assembly for receiving and transmitting millimeter (mm) waves, including at least one mm wave reflector (84, 86, 88)and at least one mm transmission wave feed (72) configured in a transmission feed location (34) within the at least one mm wave reflector. The assembly also includes a plurality of receiving mm wave feeds (72) configured in respective receiving feed locations (36) within the at least one mm wave reflector; and a radio frequency (RF) module (38). The RF module is coupled to the at least one mm transmission wave feed and to the plurality of the receiving mm wave feeds, so as to drive the at least one mm transmission wave feed to transmit outgoing mm waves and to simultaneously receive incoming mm waves from all of the plurality of the receiving mm wave feeds.
63 citations
TL;DR: Not all worldwide aspects of reflector antenna developments are touched upon in this paper, and the authors have confined themselves to the areas that have influenced their research activities.
Abstract: i»?Reflector antennas confine most of the electromagnetic energy captured over their apertures into a focal plane or redirect the radiated field of the feed into far field. This paper presents a concise history of reflector antenna developments over an extended time span. Representative examples are provided for different periods that impacted various developments of reflector antennas covering past, present, and future. Due to page limitations, not all worldwide aspects of reflector antenna developments are touched upon in this paper, and the authors have confined themselves to the areas that have influenced their research activities.
63 citations