Reflector (antenna)

About: Reflector (antenna) is a research topic. Over the lifetime, 28730 publications have been published within this topic receiving 212618 citations.

Solar energy conversion system

Abstract: A solar energy concentrator system which includes a centrally disposed column supporting a solar receiver means, and having an array of pivotally mounted support pads disposed circumferentially therearound. Each of the support pads retains a plurality of pivotally mounted solar reflective elements which are arranged to tilt about the axis of the pivotal mounting means and thereby direct reflected solar energy upon the solar receiver. The solar reflective elements are preferably generally planar, and are provided with means for tiltable as well as lateral adjustment so as to produce a Fresnel approximation of a large area reflector, and thereby increase the portion of solar energy reflected by the reflective elements onto the solar receiver.

A Solution of the Problem of Rapid Scanning for Radar Antennae

Abstract: The problem of devising a rapid scanning focusing antenna based on wave‐guide principles has been solved only approximately and not too satisfactorily. In the present paper, a known property of a plane optical system with variable index of refraction is shown to satisfy the requirements of such an antenna system. By a suitable transformation, the plane variable refractive index system can be transformed into a surface of revolution of constant refractive index which reproduces the optical properties of the plane system. This surface provides an apparently practicable solution to the scanning problem. It is shown that the diameter of the feed circle can be made arbitrarily small by judicious use of an ellipsoidal reflector.

Inexpensive modulated backscatter reflector

Abstract: The present invention provides for an inexpensive RFID Tag design which uses an inexpensive Backscatter Modulator. The modulator is simply a CMOS gate driven by a shift register containing a modulating signal. The CMOS gate is connected to the antenna such that it modulates the reflectivity of the antenna in accordance with the modulating signal. In a second embodiment, the Tag is incorporated into a single CMOS integrated circuit which comprises all of the components, except for the antenna, necessary to implement an inexpensive read-only RFID Tag.

Apparatus and method for operating a portable xenon arc searchlight

Abstract: A xenon arc searchlight or illumination system incorporates a high frequency/high efficiency electronic circuit that allows lamp ballasting and charging of the system battery to occur over a wide range of external DC power supplies. The tolerance to variations in the system battery voltage as well as external battery voltage are increased by providing logic control of the converter circuit through a programmed logic device. The intensity of the arc lamp is smoothly decreased or increased in a continuous manner from a maximum intensity to a minimum intensity beam. Ignition of the lamp at its minimum illumination levels is thereby permitted. The xenon arc lamp is uniquely oriented within the searchlight with respect to the reflector to provide the most concentrated and convergent field of illumination on which the lamp is capable, namely with the anode of the lamp turned away from the forward beam direction in the reflector. The resulting light beam is focused by relative movement of a reflector with respect to the lamp by advancing or retracting the reflector along its optical axis of symmetry on which the lamp is also aligned. The searchlight is designed so that the lamp, reflector and battery assemblies are easily field replaceable without tools. The lamp, ballast, battery and charger are provided in a single rugged package which can be sealed for field use. The searchlight is combined by an appropriate mounting adaptable with other optical detector devices such as cameras, binoculars and night vision telescopes. The beam output is similarly usable with a combination of filters to allow the most varied intensity and wavelengths for a particular application, such as smoke filled environments, surveillance employing near-infrared or infrared illumination, ultraviolet, underwater illumination or illumination with any color in the visible range.