Showing papers on "Reflector (antenna) published in 1973"

Cool wall radiantly heated reactor

Abstract: A cool wall radiantly heated chemical vapor deposition reactor includes a plurality of banks of elongated heat lamps surrounding the radiant energy transmissive wall of the reactor for heating the susceptor in the reactor on which the wafer substrates are supported. Each bank of lamps includes a segmented reflector assembly having the reflector segments spaced from each other to provide slots aligned with the lamp filaments for permitting a gaseous coolant to be introduced from a cooling structure into contact with the lamps and with the wall of the reactor and which precludes direct reflection of radiant heat back on the lamp filaments which would cause damage thereto and shorten lamp life. Furthermore, reflector segments are arranged to isolate the individual lamps in each bank from each other to further enhance lamp life by precluding direct filament-to-filament radiation transfer between adjacent lamps. The reflector segments are hollow and the cooling structure is designed to introduce the gaseous coolant directly into the hollow interior of the reflector segments from which the coolant thereafter circulates through the slots and over the lamps. Each reflector segment may also be provided with conduit means through with a liquid coolant is circulated to additionally cool the segments.

Pollutant Detection by Absorption Using Mie Scattering and Topographic Targets as Retroreflectors

Abstract: Remote pollutant measurement by absorption using topographical reflectors or atmospheric Mie scattering as a distributed reflector offers increased range and sensitivity compared to that achieved by Raman or resonance backscattering methods. The use of topographical reflectors offers the advantage of a single-ended absorption measurement for ranges up to 10 km and sensitivities to less than 0.01 ppm for a 10-mJ, 100-nsec transmitted pulse. The distributed Mie reflector permits absorption measurements over a depth cτ/2, determined by the pulse length τ, and allows ranging by time-of-flight measurement. For a 100-mJ, 100-nsec pulse sensitivities to 0.3 ppm at a 15-m depth resolution to ranges of 1–4 km are possible. This sensitivity is 104 to 105 times better than that achieved by the Raman method.

Reflector antenna with improved scanning

Abstract: A Cassegrainian antenna system has a planar array as the feed. An intermediate reflector is positioned in the near field of the array for substantially collimated illumination with all array elements operating in phase. Accordingly, an on-axis main beam is radiated from the main reflector upon illumination by energy from the intermediate reflector. By impressing a linear phase gradient across the array, the main beam is controllably tilted off-axis.

Reflector lamp cooling and containing assemblies

Abstract: A cooling assembly particularly suitable for use with high brightness light sources requiring compact housing. The assembly comprises an air cooled heat sink and a connecting means being flexible and having a high thermal conductivity coefficient. This device provides an efficient method for cooling filament leads in the seal end of high brightness lamps and the joint between the lamp and reflector, thereby increasing lamp life.

Electronically step-by-step rotated directive radiation beam antenna

Abstract: This invention relates to an electronically rotatable antenna which includes several radially arranged Yagi antennae having a common drive element. Reflector and director elements of each Yagi antenna are sequentially rendered operative by biasing suitable diodes short-circuiting them to a ground-plate. The radiation pattern is step-by-step rotated. Directivity is increased by short-circuiting other elements belonging to other arrays than the main one, those elements defining generatrices of a parabola having the driver element as a focus and the reflector element as an apex.

Reflector with interspersed angled reflex elements

Abstract: The reflector is constructed of transparent material and has on its rear face a plurality of first and second retrodirective reflector elements. The optical axes of the first reflector elements are arranged at a different angle than the optical axes of the second reflector elements. The first and second reflector elements are interspersed with each other so that the reflector appears substantially fully illuminated throughout its area to a viewer who is located within a zone defined by the optical axes.

Reflector antenna radiation pattern analysis by equivalent edge currents

Abstract: Equivalent edge currents, derived from the edge diffraction theory for a half-plane, are used to obtain the radiation patterns of a parabeloidal reflector antenna when illuminated by a source at the focus. Cylindrical wave diffraction coefficients are used. The method avoids infinities at caustics and shadow boundaries thus giving solutions which are finite everywhere. A slope-wave equivalent current correction term is applied when the illumination is tapered towards the edge of the reflector. Comparisons are given with the physical optics approach and experimental results.

Light emitting diode assembly

Abstract: A light emitting diode assembly which includes a light reflector formed at one end of, and as an integral part of a first electrical supply lead; a light emitting diode mounted within the reflector, one side of the diode junction being connected in electrical contact with the reflector which in association with the first lead provides a high heat sinking facility; and a second electrical supply lead one end of which is connected in electrical contact with the other side of the diode junction. The diode, the reflector and the said one end of the second lead are encapsulated in a bead of a light transparent material.

The generalized multiprobe reflectometer and its application to automated transmission line measurements

Abstract: The multiprobe reflector can perform the measurements usually performed with the slotted line without the need for mechanical adjustment, thus making it ideal for automated systems. Theory is presented showing how impedance data may be obtained from three or more arbitrarily placed probes; the spacing need not be at any particular fraction of a wavelength thus permitting very wide band operation. The use of additional probes permits measurement of frequency and also self checking of the system, thus providing accuracies comparable with the best slotted lines available. The simplicity of the hardware makes it easy to install in both standard and non-standard waveguides and transmission lines thus avoiding the use of adaptors with their attendant errors. A brief error analysis is included. Measurements of antenna impedance and wall loss, using a nonstandard size of waveguide, are presented and show an accuracy comparable with the best slotted lines.

Cube-corner reflector with non-aligned cube axes and element axes

Abstract: The reflector is constructed of transparent material and has a plurality of cube-corner reflector elements at the rear and a light-receiving face at the front. Each of the reflector elements has an element axis and a cube axis with an angle other than 0* therebetween. Each of the reflector elements has an outline in the shape of a regular polygon when projected in a plane perpendicular to the element axis. The faces of each element are symmetrically arranged with respect to the cube axis. The element axes of the reflector elements are all parallel to one another.

Retrodirective reflector visible over wide range of observation angles

Abstract: The reflector is constructed of transparent material and has a plurality of reflector elements at the rear and a light-receiving face at the front. Each reflector element has three faces intersecting at three edges, three dihedral angles being respectively defined by the intersection of adjacent faces. Two of the dihedral angles of all of the reflector elements are substantially 90*. The third dihedral angle of at least some of the reflector elements is substantially greater than the angle of the other two dihedral angles, so that light reflected by the reflector is diverged into an elongated pattern.

Ir generator having ellipsoidal and paraboloidal reflectors

Abstract: An infrared generator wherein an ellipsoidal reflector has a source rich in infrared radiation at one focus thereof. The end of the reflector at the other focus merges with a paraboloidal reflector positioned so that the focus of the latter reflector coincides with the said other focus of the former. The axes of the reflectors intersect, preferably at right angles to each other.

Apparatus for precisely thrusting pipes into the ground

Abstract: Herein disclosed is an improved apparatus for precisely thrusting pipes into the ground along a predetermined straight guide line. The apparatus includes a guide tube coaxially inserted in the pipe and actuated for proceeding and rotation, and an augar coaxially attached to the front end of the guide tube for excavating the front soil. In the apparatus, a laser beam source is used for generating a laser beam as the guide line which is normally running forward on the axis of the guide. This laser beam is reflected on a parallel reflector which is disposed at a relatively front portion of the guide tube in a manner to have its critical optical path coincident with the axis of the guide tube. In the apparatus, a displacement detecting device is also provided for detecting actual displacement of the common axis of the auger and the guide tube from the laser beam guide line in terms of optical displacement of the reflected backward laser beam from the forward laser beam. To this optical displacement is responsive a displacement correcting mechanism, which is interposed between relatively front portions both of the pipe being thrusted and the guide tube, so that the guide tube may be deflected relative to the pipe in the radial direction to reduce the actual displacement.

Interference patterns of a horizontal electric dipole over layered dielectric media.

Abstract: Interference patterns for electromagnetic fields due to a subsurface reflector below a layered lossy dielectric are calculated with the geometrical optics approximation for use in interpreting data to be collected on the moon by Apollo 17 as well as data currently being obtained on terrestrial glaciers. The radiating antenna lies on the surface. All six field components are calculated and studied. For the endfire solutions, the peak of the first reflected wave is found to be different from that of the broadside ones. To facilitate a physical discussion, we plotted the radiation patterns due to the antenna on the surface.

Radiation fields inside an elliptical photoreflector with a source of finite spatial dimensions

Abstract: Using the Extense Source Formulation (Irazoqui et al., 1973a), a radiation distribution model for the tubular lamp-elliptical reflector system was developed for predicting energy density profiles inside the elliptical cavity of the system. It introduces a significant improvement over the linear-lamp models since it avoids any form of singularities in the prediction of radiation energy density profiles at the focal points of the elliptical reflector. Also, all lamp and reflector dimensions are parameters of the model. Calculated results agree well with published experimental data for a similar lamp reflector set up. One of the most important conclusions is the absence of uniform irradiation from all radial directions at the reactor location.

Solar heating device

Abstract: A solar heating device comprising an upright tubular post, a rigid support member protruding perpendicularly from the post, and a generally paraboloidal reflector having a rigid arm extending along the axis of the reflector from the center thereof towards the focal point. A pivot perpendicular to a free end of said arm is selectively pivotally mounted and secured in one of a plurality of notches in said support member to provide a compensation for the lateral displacement of the focal point as the reflector is tilted. A height adjustable grid mounted on a tube slidably received within the post enables the support of an object to be heated. A rod indicating the focal point of the reflector can be disposed along the axis thereof.

Scale model development of a high efficiency dual polarized line feed for the Arecibo spherical reflector

Abstract: The experimental development of a 1:6.535 scale model line feed for the Arecibo spherical reflector is described. The 14.7-ft long model at 2810 MHz simulates a 96.6-ft feed at 430 MHz capable of illuminating the full 1000-ft aperture of the reflector. The feed design requirements are discussed and an experimental program is outlined in which the necessary line source parameters were established using a number of leaky cylindrical test sections. Experimental measurements of both the near and far fields of the model feed are described and typical results are quoted and discussed. Finally, some results obtained after installation of a full size feed in the reflector are given and compared with predictions based on the model data.

Steerable radar antenna

Abstract: A steerable radar antenna having a fixed energy feed requiring no rotary joints in the waveguide, including a microwave lens and a moveable reflector which operate conjunctively to collimate and direct the RF energy, and a drive means.

Radiant energy reflectors

Abstract: A light projector particularly suitable for automobile headlights which will direct the light to provide separate beams substantially without energy loss. The light projector is provided with a rear reflector which may be of parabolic shape or partially or entirely of the shape of an anamorphoscope. It has a second rear reflector of elliptical shape having one of its focal points in the light source. There is also provided a spherical front reflector having its origin in the light source. The front reflector has an aperture located in the second focal point of the elliptical rear reflector. A plano-convex lens may be provided having its focal point in the aperture of the front reflector to project an intense light beam having the shape of the aperture. This will now provide two light beams of different intensity, one being very intense which may be of rectangular shape corresponding to the shape of the aperture. The projector may also be used to direct or project any radiant energy such as electromagnetic waves or sound waves.

Device for varying magnification produced by an optical system

Abstract: A device comprising a lens movable in the direction of its optical axis, and a reflector disposed in an inclined position on the optical axis of the lens and movable therealong, the lens and the reflector being interconnected by a link mechanism. The link mechanism is constructed to satisfy the following relation:

Pebble-bed reactor with graphite side reflector - having indented inner face to prevent retarding of fuel descent

Abstract: A side reflector for a nuclear reactor is situated between the core and the thermal shield and constituted of stacks of prismatic graphite blocks, defining a cylindrical chamber to contain the spherical fuel elements. A large number of the graphite blocks have, on their reactor-facing side, a depression, extending in the direction of flow of the fuel elements at least for two element dias. and transversely to that direction by at least one element dia; the depth of each depression is 1/4-1/2 (1/3) of an element dia. Pref., these depressions each extend both tangentially and axially; they may be elongated having their longitudinal axis parallel to the longitudinal axis of the cylindrical core space; or they may be circular. Appts. is used esp. in a pebble-bed reactor, where the braking effect of the side reflector tends to retard the downward travel of the fuel elements in the peripheral zone. By interrupting the surface of the reflector by a series of the depressions described, this retarding effect is largely neutralised so that all elements travel downwards at the same speed.

Longitudinal mode selection in lasers with three-mirror reflectors.

Abstract: The complex reflectance of a combination of three parallel mirrors with arbitrary distances is computed. If the distance between the mirrors is equal to an integer multiple of a certain wavelength of the incident light, the reflectance of the system has narrow maxima and broad minima as a function of wavelength. This behavior is opposite to a usual two-mirror Fabry-Perot interferometer. It is suggested that such a combination of three mirrors as a mode selective laser reflector be used. Compared with other mode selecting devices this arrangement should be simpler in construction and should have better mode selective properties.

Ultrasonic rodent control

Abstract: Apparatus for generating and radiating ultrasonic sounds at frequencies known to adversely affect the nervous systems of pests, such as rats, the apparatus comprising a housing for electronic circuitry, a transducer for emitting the sound, and a reflector for concentrating the radiated sound in one direction; said electronic circuitry including a novel Darlington oscillator circuit using a crystal transducer having a feedback electrode and the crystal also establishing in conjunction with an inductive tank circuit the frequency of oscillation, the apparatus also including a visual indicator to show the ''''on'''' and the ''''off'''' condition of the oscillator since the oscillation is outside the audible range of humans.

Radiant energy collector or reflector

Abstract: A light projector particularly suitable for automobile headlights which will direct a plurality of concentric light beams of different intensities substantially without energy loss. The light projector is provided with a stepped rear reflector of parabolic shape or partially or entirely of the shape of an anamorphosscope. It also is provided with a first front reflector of parabolic shape and a second front reflector disposed inside of the first front reflector of substantially spherical shape. The first front reflector may also be partially or entirely of the shape of an anamorphoscope corresponding to that of the rear reflector. The second front reflector substantially obscures the light source from an observer above a predetermined plane such as a horizontal plane. This will minimize the danger of glare to an approaching driver. On the other hand it will direct substantially all of the light onto the road and permit the beam to reach farther out with the same amount of candle power. The projector may also be used to direct any radiant energy such as electromagnetic waves or sound waves. Additionally it may be used not only to reflect or project radiant energy but also for collecting radiant energy into a focal point.

One-Speed Neutron Transport Problems-Part II: Slab Transmission and Reflection and Finite Reflector Critical Problems

Abstract: The problem treated in Part I in terms of a continuous µ-variable is here treated in the double-PN approximation for azimuthally symmetric situations. Exqplicit representations for basic matrices a...

Combination spotlight and floodlight

Abstract: The light of this invention may be operated so as to emit a floodlight beam or can be focused into a spotlight beam. The apparatus includes a reversible drive for moving the light reflector between a floodlight position wherein the reflector has its least curvature, and a spotlight position wherein the reflector has its greatest (parabolic) curvature.

Method of making radar reflective buoy

Abstract: A method of making a seamless, hollow, spherical fishing buoy of thermoset resin, preferably cross-linkable polyolefin, by rotationally molding the same without vent holes or openings in the buoy. A 3-plane, rigid, corner cube radar reflector is mounted inside the spherical buoy, and is oriented to provide maximum return of a radar signal from anywhere on or above the horizon. The reflector is centered within the mold cavity by six spring-loaded standoffs, which are attached to the corners of the reflector. The standoffs are molded of the same resin as the buoy, but are only partially cross-linked. During molding cycle, the cross-linkable resin molding powder melts and spreads uniformly over the inside surface of the mold, at the same time cross-linking. The ends of the partially cross-linked standoffs in contact with the hot mold melt and become part of the plastic shell, and also continue cross-linking with the latter. The springs allow the standoffs to follow the mold as the latter expands and contracts, while keeping the reflector accurately centered in the cavity.

Multi-beam lighting device

Abstract: A lighting device comprises an elliptical reflector with a holder for locating a lamp with its filament at one of the foci of the reflector. A beam splitting device in the form of two planar mirrors is arranged between the reflector and its other focus to reflect two beams of light from the lamp transversely of the axis of the reflector in opposite directions. Two optical systems comprising concave mirrors and converging lenses are located in the paths of the two beams respectively to reflect the beams so that they meet at an acute angle to one another and to form focussed images of the lamp filament at the place where the beams meet.

Dual-band reflector-feed element for frequency-reuse applications

Abstract: Proposed frequency-reuse systems have created a need for reflector-feed elements that generate symmetrical primary patterns with low crosspolar content. The letter describes a horn radiator of only 1? diameter that meets these requirements over two discrete frequency bands.

Astigmatism in reflector antennas

Abstract: The characteristics of the astigmatic phase error in large parabolic reflector antennas are described. A procedure for focusing an antenna and diagnosing the presence and degree of astigmatism is given.