Abstract: An improved support rib for a satellite dish antenna is disclosed wherein a male side rib selectively engages a female side rib continuously along the longitudinal length of the support rib and wherein the male and female side rib each comprises a continuous engagement device having a lower channel for selectively receiving the side of a parabolic reflective petal and an upper member for one-time flexing downwardly over the lower channel to firmly engage and hold the side of the reflective petal continuously along the longitudinal length of the support rib. When flexed downwardly, the upper member lies in the same plane as the support rib and the petal.

Abstract: A parabolic antenna comprises a parabolic reflector having a flange at outer periphery of reflector contiguously and an antenna fitting integrally formed with upper and lower fitting arms to be secured to upper and lower portions of the flange, respectively. The back of the parabolic reflector is fixedly mounted to the antenna fitting through the upper and lower fitting arms and fixed on an antenna support post.

Abstract: The present invention relates to a reflective assembly for use in an antenna for receiving an incident microwave signal having a wavelength .lambda.. The reflective assembly is comprised of a sequence of microwave reflective surfaces facing in a common direction. Each reflective surface is at least a portion of a concave surface of one of a corresponding sequence of paraboloids that have a common axis and a common focal point. A unit is provided for mounting the reflective surfaces in an array such that when the incident microwave signal is received parallel to the access, each reflective surface reflects the incident microwave signal as a reflected microwave signal onto the common focal point, wherein each reflected microwave signal arrives at the common focal point in-phase with each other of the reflected microwave signals.

Abstract: A telecommunications antenna is provided with a reflector having a semi-offset geometry, a feed mounted on a feed source rigidly fixed to the reflector, an antenna pedestal for supporting the reflector and the feed. Positioning of the feed is such that, in respect of a reflector illumination half-angle .beta. as seen from the feed such that 45.degree.<.beta.<55.degree., the offset angle .alpha. (angle between the focal axis .DELTA..sub.Foc and the median ray of the total beam which is emitted by the feed and illuminates the reflector) is 25.degree.<.alpha.<35.degree., the antenna mount being of the azimuth-elevation type known as an az-el mount.

Abstract: A reflector-type microwave antenna includes a paraboloidal reflector and a feed horn located at the focal point of the reflector for launching microwave signals onto the reflector and receiving microwave signals from the reflector. A supporting frame for the reflector and feed horn includes three arms extending along the rear side of the reflector to three spaced mounting locations on the rear side of the reflector. The arms are fastened to the spaced mounting locations on the rear side of the reflector by fastening means having a loose condition in which the arm is attached to the reflector but free to move relative to the reflector, and a tightened condition in which the respective arm is rigidly attached to the reflector.

Abstract: A satellite transmission receiving antenna with unique mounting provisions for a recreational vehicle roof. A generally cylindrical collar extends upward from the vehicle roof and attaches to a load distributing panel under the collar and over the area of the vehicle roof for load distribution. A parabolic reflector is hinged along an edge to a generally horizontal turntable within the collar so that the reflector may be rotated to a concave downward position to act as a weather cover over the collar and also to provide smooth aerodynamic conditions during transport. Rotation of the turntable through a motor driven gear coupling to the turntable effects azimuth positioning of the antenna and elevation angle is set by a linear actuator.

Abstract: A DBS antenna comprises a support arm (10) which at its front end supports a converter/feed unit (12) and at its rear end is secured to a mounting bracket. The antenna dish (14) is mounted on the support arm (10), so that the dish (14) is supported by the arm (10) without mechanical loading from the converter/feed unit (12). The converter feed unit (12) may have a tapering cover portion (74) of sufficient electrical thickness to produce focussing of the signal into the waveguide feed.

Abstract: A receiving head end comprising only a single movable component, a front depolarizer (POM), for selecting conjugate polarized microwaves. The addition of a fixed depolarizer (POF) provides two aerial versions, one for the circular type of polarization and the other for the rectilinear type of polarization. The whole is fitted together for forming an aerial for the "public at large", simple to operate and whose shadow cast on the parabolic reflector is minimal.

Abstract: An enclosed terrestrial antenna system of monocoque construction for receiving television signals from satellites in geostationary orbit. The basic antenna comprises two dish-shaped members having substantially identical configurations, each of which is a surface of revolution. Each member (called a "dish" in the industry) has a central concave parabolic area surrounded by an upstanding frusto-conic rim. One, the antenna dish, has an electromagnetic radiation reflecting surface on the concave side. The other, the cover dish, is substantially transparent to electromagnetic radiation. The cover dish has an opening at the center, along the axis of revolution. The two dishes are secured together, concave face to concave face. A feed mount is secured to the cover dish over the opening and carries the feed assembly in a manner allowing the feed assembly to be moved toward and away from the reflective surface to focus the feed.

Abstract: A guy system is disclosed for a parabolic reflecting antenna having a reflecting surface and a signal receiver or feedhorn mounted at its focal point. A plurality of stays or guy wires is secured to the feedhorn, each of such guy wires extending through the reflecting surface to an anchor point behind the antenna substantially at or near its vertex. The resultant force acting on the antenna as a result of tension in the guy wires is thereby substantially tangential to the curvature of the reflecting surface.

Abstract: A grid parabolic antenna formed of a peripheral hoop and a plurality of metallic reflector ribs arranged in planes substantially parallel to each other and connected to the hoop. The reflector ribs each have an elongated cross-sectional configuration, with the elongation being in a direction that is generally parallel to the axis of the antenna feed which is at the focus of the parabola.

Abstract: An antenna fabrication scheme for shaped reflector analyzes the geometry of the shaped reflector to be fabricated. On the basis of this analysis, a surface of revolution which closely approximates the shaped reflector is defined. The axis of revolution of the generated surface can then be employed by a single reflector shaping tool to describe the surface of revolution a portion of which approximates that of the desired shaped reflector. The shaped reflector is then effectively removed from the described surface by defining the perimeter of the shaped reflector on the surface of revolution.

Abstract: A low-cost, essentially self-contained microwave earth station having a reflector dish together with the microwave sensing/emitting elements embedded in a rigid, low density and low thermal conductivity plastic foam. At least the sides and back of the unit may be encased in a fiberglass-resin shell. Shielding for terrestrial interference also may be present. For a receive-only station, a low noise amplifier together with frequency conversion and channel selection (or all-channel transmission) to circuits may also be embedded in the foam. The only connections to such a receive-only unit are a line from a d-c source of power for supplying the required operating voltages to the electronics, and a coaxial cable supplying the selected one of the received information signals to the TV display or other device utilizing those signals. Preferably, a single coaxial line with the dual function of information output and d-c power input is employed.

Abstract: A parabolic reflector for combined use as a solar concentrator and communications antenna having both a shared and joint use mode. In both the joint and shared use mode, the dish concentrates the electromagnetic energy at the focal point where a signal receptor such as a feed horn and LNA captures the signal. In the shared use system, a heat exchanger is positioned to receive solar flux and the signal receptor is shielded or is in an out-of-the-way position during periods of high solar energy. In a joint use system, the location of the receptor of solar energy and the receptor of electromagnetic energy are separated by use of selective surfaces which selectively reflect and absorb energy. In one embodiment, a wire mesh having a mesh size of less than approximately one-sixteenth of the wavelength of the signal radiation is interposed to reflect electromagnetic energy to the signal receptor but allows solar energy to pass through to impinge upon the heat exchanger.

Abstract: An improved hydraulic reflector is provided for use as an antenna or solar reflector or the like, wherein the reflector is collapsible for highly compact stowage within a space vehicle and for convenient deployment in space to an expanded, generally dish-shaped configuration. The reflector comprises a rigid central dish hinged to a peripheral array of hingedly interconnected rigid panels which in turn carry a peripheral array of outwardly radiating extension ribs supporting an outer ring of flexible reflector material. The rigid panels and the extension ribs are movable together between a collapsed state folded substantially into a cylindrical envelope defined by the diametric size of the rigid central dish and a deployed configuration lying generally within a surface of revolution common to the central dish, such as a paraboloid surface in the case of an antenna.

Abstract: A satellite dish antenna having parabolic-shaped support ribs firmly engaging the sides of adjacent screen-mesh reflected petals along the entire longitudinal length of each petal. Each support rib having an upper reflective surface lying in the same plane as the surface of the reflective petal, under which is located a locking arrangement which engages adjacent reflective petals the entire length of the petal.

Abstract: The antenna (e.g., a transportable, lightweight and cheap antenna for temporary earth stations) is constructed out of three components. The center component is a circular/parabolic dish. The side components extend the dish to give the composite a major diameter and a minor diameter. In use the antenna is aligned so that the major diameter is aligned with the direction of the geostationary arc.

Abstract: The antenna comprises a parabolic reflector (1) and a primary source (2). The reflector (1) comprises a first grating of conductor wires (7) and a second grating of conductor wires (8) which are orthogonal to the wires of the first grating, and with both gratings constituting elliptical reflective surfaces. The sizes of the major and minor axes of the ellipses are determined in such a manner that both operating frequencies of the antenna have identical coverge zones on the surface of the globe.

Abstract: An adjustable bracket mount for mounting certain functional components such as a feed horn and a low noise amplifier feed assembly on a satellite antenna dish at the prime focus or other desired location above the antenna dish, which mount includes a base secured to the dish, a bottom support extending from the base toward the prime focus, a sloped offset bracket having one end provided in adjustable cooperation with the bottom support and the opposite end carrying a top support. The top support extends in parallel relationship to the bottom support and projects above the bottom support and a top bracket is adjustably mounted on the top support and features outwardly-extending arms designed to carry the feed assembly and mount a cover. Two variations of the top bracket are employed and a cone-shaped cover is provided to protect the feed assembly from the elements by mounting on both versions of the top bracket.

Abstract: A membrane concentrator mirror comprises a rigid, circular-segment-shaped frame-like basic body with a hermetically closed bottom wall, the basic body having a union device for connection with a conduit leading to a device for generating sub-pressure, a membrane being hermetically stretched over the basic body in such a way that it is deformable under the influence of a sub-pressure, and this membrane consisting of a plurality of membrane segments the outer end of which is limited in a circular segment shape, the membrane segments being connected with one another along radially extending rims. An improvement of the optical quality and a reliable connection of different membrane sections is to be achieved. To this effect the membrane segments are connected with one another in such a way that rigid, radially extending clamping profiles secure the radially extending outer rims by means of clamping devices.

Abstract: A parabolic antenna for SHF band having a primary feeder and a reflector is improved by using a backfire helical antenna as a primary feeder, which is fed by using a coaxial cable. The backfire helical antenna has a matching disc coupled with an outer conductor of the coaxial cable feeder, and a coil, one end of which is coupled with an inner conductor of said coaxial cable. The other end of the coil is free standing. The coil is positioned so that the axis of the coil coincides with the axis of the reflector, and the feed end of the coil locates nearer to the reflector than the free standing end of the coil. The present antenna is useful in particular for a receiving antenna for a direct satellite broadcasting.

Abstract: A reflector antenna having an adaptive nulling assembly. The assembly comprises a disk shaped mounting plate having a shaft aligned with the rotational axis thereof and passing through the main reflector focusing surface. An absorber of electromagnetic energy is affixed to the disk and a microwave grating of metallic elements is positioned on the surface of the absorber. The amplitude of the nulling signal is controlled by rotating the assembly, and the phase of the nulling signal is controlled by the varying height of the grating above the reflector. Additional nulling elements can be used to null multiple interference sources.

Abstract: An antenna feed structure for use with a parabolic reflector in amplitude-comparison monopulse radar applications employs a dedicated transmit feed centered within a four-port receive array of conventional element spacing to eliminate the need for a circulator or other transmit/receive device while retaining satisfactory receive array performance. Isolation pins placed around the transmit port act to decouple it from the receive ports, and a double waveguide run to the transmit port reduces uneven heating and related phase imbalance in adjacent receive waveguide runs.

Abstract: An antenna system includes a reflector which is a part of a paraboloid of revolution or parabolic cylinder, a primary radiator for clockwise circularly polarized wave, and a primary radiator for counterclockwise circularly polarized wave. The reflector is of geometrically asymmetrical shape to effect different reflection properties for clockwise and counterclockwise circular polarizations. The primary radiators are fixed at two different positions in the vicinity of the focus of the paraboloid reflector.

Abstract: A dish antenna structure (10) is formed from a plurality of ribs (14) which extend from near the center of the dish to its periphery, and which support antenna panels (18) between them. Each rib has an outer flexible plastic sheath having grooves (44,45) in its side edges which receive the edges of antenna panels (18) and a hollow longitudinal channel (40) within which a rigid support member (42) is fixed. The support ribs (14) and the antenna panels (18) are curved such that the anterior surface of the dish defined thereby is parabolic.

Abstract: A parabola antenna has a parabola surface whose thickness is uniformly decreased from an outer circumferential portion to a central portion of the parabola surface. The thickness of the parabola surface is smallest at the central portion.

Abstract: An overmoded waveguide transition comprises a flared waveguide section having different transverse cross-sections at opposite ends thereof, the longitudinal shape of a section of the transition adjacent an end thereof being defined by the equation:(r.sup.p /a)-(l.sup.p /b)=1where a and b are constants, r is the radius of the transition, l is the axial distance along the transition measured from one end, and the exponent p has a value greater than two.

Abstract: A mount for supporting a feedhorn/LNA assembly in a parabolic satellite antenna is disclosed, said mount providing a sturdy support for positioning the feedhorn/LNA assembly at the focal point of the antenna and providing means for skew adjustment of the LNA probe.

Abstract: A backfire feed antenna has a parabolic reflector with a ring-focus at the reflector focal point comprising a dielectric waveguide having a stem portion and a cap portion with a pointed end and most of the stem portion inside a conducting tube along the axis of the parabolic reflector. The outer surface of the cap portion is concave outward and convex inward and covered with a conducting layer. A curve between a parabola and hyperbola defines the surface. The cap portion has a conical surface extending between an annular surface at the junction between the stem portion and the cap portion and an axially extending circumferential surface surrounding the conducting layer. The inside end of the dielectric waveguide is pointed.

Abstract: An antenna system which has omnidirectional coverage in azimuth and sectoral coverage in elevation. A main reflector including a reflecting surface has polar symmetry about the Z-axis. It also has a cross section in any plane containing the Z-axis which satisfies the laws of power conservation and reflection. It is determined by the desired far-field pattern and the microwave feed pattern (for example TM.sub.01) employed. Single or dual reflector systems are described. Using the system on "receive" with multiple "feeds", full azimuthal direction finding of incident radiation can be achieved.

Abstract: A satellite antenna particularly adapted for use on a recreational vehicle such as a house trailer or mobile home, having a roof surface, the antenna including a base plate mounted on the vehicle roof surface, a support plate rotatably secured to the base plate and rotatable about a generally vertical axis for at least about 360 degrees, a parabolic satellite signal reflector having a focal axis, the reflector being pivotally secured to the support member, a variable length member, such as a screw type cylinder for selectively pivoting the parabolic reflector relative to the support member, and a feed arm pivotally secured to one end to the parabolic reflector, a signal receiving feed horn mounted on the other end of the feed arm, the feed arm being pivotal to a position wherein the feed horn is coincident with the focus apex of the reflector and to a rest position in which the feed horn is retained within the confines of the reflector interior surface and linkage means to automatically pivot the feed arm to

Abstract: A low cost tapered horn with desirable equal E and H plane pattern beamwidths is achieved with one or more annular channels in the tapered wave translation surfaces of the horn. These channels extend concentric and parallel with the axis of symmetry of the horn to permit the horn including the channels capable of being formed using molding techniques.

Abstract: Elements of a radar antenna are provided with one or more electromagnetic actuators capable of moving the elements (scanner or parabolic reflector), independently of the support system in response to electrical signals applied to the coils of the electromagnetic actuators.

Abstract: A double grid reflector antenna for radiating different signals having pure linear orthogonal polarization comprises a couple of identical and superposed reflecting grids. One of said grids has been rotated its boresight to disengage its focus from that of the other, and feeds are set in the focal plane of the respective grids. The front grid reflects indifferently either horizontal or vertical polarization, while transmitting the orthogonal polarization to be reflected by the rear grid.

Abstract: The ribs of a mesh-type parabolic antenna or the like are clamped in a radial arrangement between the side walls of adjacent wedges in a hub. The hub includes a plate with a flange extending from the interior thereof. The wedges are arranged on the plate radially about the circumference of the flange. Each wedge has side walls tapering inwardly toward a front end thereof. The front ends of the wedges are drawn toward the flange and fastened thereto, thereby clamping the ribs therebetween. Each of the ribs includes a channel, and a plurality of locking strips are provided for insertion into the rib channels. Antenna mesh panels bridging adjacent ribs are held to the ribs at the panel edges by the locking strips.

Abstract: Support structure for a paraboloid reflector of electromagnetic radiation. The structure comprises a plurality of abutting flat ribs arranged on edge in rotated concentric square patterns, with the ends of inner ribs meeting the sides of adjacent outer squares at forty-five-degree angles. The concave parabolic forward edges of the ribs are aligned at their junctures, establishing the curve of a screen reflector. Corner gussets are positioned on parallel planes that are perpendicular to the focal axis of the paraboloid. The structure is assembled by inserting fasteners through matching holes in the ribs and corner gussets.

Abstract: The multiple feed antenna comprises a primary focussing element and at least two feeds. The feeds are spaced from each other and have different characteristics such as different frequency bands. The focussing element is moved such that its focal point coincides individually with the feeds. The focussing element may be designed to be offset with respect to its focal axis. In this manner, the antenna may have a common aperture and common boresight for each of the feeds.

Abstract: Suppression of selected sidelobes in a reflector antenna is accomplished by the positioning of two or more metallic disks on the reflector surface at specific distances above the reflector surface.

Abstract: In general a coaxial feeder connected directly into the center of a half-wave dipole antenna disturbs electrical balance and therefore reduces the effectiveness of the screen of the feeder. In the present invention a dipole with two quarter-wavelength elements symmetrically connected through respective identical capacitors to the screen of the feeder is fed through an inductor connected to the junction between one element and its capacitor. By having equal reactances, the capacitors balance the dipole to earth and by means of its phase delay the inductor restores a resistive impedance termination for the feeder.

Abstract: The present invention relates to a scanning beam antenna comprising a doubly-curved main reflector, a doubly-curved subreflector and at least one linear array feed. The main reflector is doubly-curved in two planes to produce a separate first focus for each feed in a first plane in front of the subreflector and a separate second focus for each feed in a second orthogonal plane behind the subreflector. The subreflector is curved to refocus each second focus of the main reflector to coincide with the image line of a first axis on the reflecting surface of the main reflector in the first plane. Each feed array is disposed at a separate secondary focus of the combination of the main reflector and subreflector. The resulting antenna provides very little phase error due to aberrations as each beam is linearly scanned.

Abstract: An antenna system in which primary radiators are disposed on the radiation side of beams from a main reflector and in opposition to a subreflector and in which the subreflector and the primary radiators are disposed in positions offset from beam blocking positions.

Abstract: A portable, lightweight, folding parabolic reflector antenna for reception of microwave signals includes an axial wave guide tube which constitutes the main structural supporting member of the antenna, a ten to fifteen foot diameter dish mounted to the wave guide and a sub-reflector supported at the forward end of the wave guide. A low noise amplifier may be mounted to the rear end of the wave guide for amplification of the received signals. The folding dish includes a pre-formed dished reflector of pliable material supported by a radial framework of normally straight resiliently flexible spokes of tapering cross section. The spokes are pivotable by a lever system between a folded axial position and a deployed radial position.

Abstract: The present invention relates to a horn antenna which provides minimized cross-polarization in the far field of the antenna. The antenna arrangement comprises a horn including four walls wherein a first pair of opposing concentric conic walls are associated with a common longitudinal axis, and a second pair of opposing planar walls are aligned radially to the common longitudinal axis of the cones. The walls taper down from an offset parabolic main reflector to intersect a common apex corresponding to a focal point of the main reflector. The longitudinal axis of the horn is arranged at a predetermined angle to the common longitudinal axis of the cones to minimize cross-polarization in either one or both of the TE.sub.01 or TE.sub.10 modes in the far field of the antenna.

Abstract: A horn-reflector antenna comprising a paraboloidal reflector for transmitting and receiving microwave energy, and a flared feed horn for guiding microwave energy to and from the reflector, the longitudinal shape of at least a section of the horn at the end where the horn begins to flare outwardly being defined by the equation ##EQU1## where R is the transverse dimension from the longitudinal axis of the horn to the side wall of the horn 1 is the axial distance along the horn measured from the end where the horn begins to flare outwardly, R.sub.1 and R.sub.2 are the radii of the horn at opposite ends of the horn section defined by the equation, L is the axial length of the horn section defined by the equation, and the exponent p has a value greater than two and less than about 7, to effect a substantial reduction in the TM.sub.11 mode level.

Abstract: A compact satellite broadcasting receiver comprises a circular waveguide, a strip-line-shaped probe projected into the circular waveguide, a reflecting element provided downstream of the probe in the circular waveguide and a microwave circuit having a strip line provided around the circular waveguide and connected with the probe. Furthermore, a satellite broadcasting receiver capable of simultaneously receiving two kind of microwaves polarized perpendicularly to each other is realized by joining two compact satellite broadcasting receivers as mentioned above with their strip-line-shaped probes placed at a right angle.

Abstract: A compact, easily manipulable measuring device is provided, particularly useful for properly positioning the feed horn of a parabolic reflector antenna, or the like, relative to the satellite reflecting dish of the antenna. When installing or maintaining an antenna, it is important for optimum signal reception to position the feed horn at or near the focal point of the satellite dish. Such feed horns typically present a central axis, which if aligned with the center point of the satellite dish approximately positions the feed horn at the focal point of the satellite dish. The device of the present invention presents a telescopic rod structure coupled to a support head. The support head presents structure for attachment to the feed horn such that the rod structure preferably lies along the feed horn central axis.

Abstract: A reflector and method for making the same involves joining a set of curved reflective segments together to form a concave reflector having a focal point common to all of the segments. Each segment is conveniently a quarter section of the overall reflector, for example, and includes a pair of connecting plates arranged generally perpendicularly with respect to one another along its peripheral edges. The plates of adjacent segments may be joined together such that each segment and its associated plates are directed generally towards the common focal point. The various segments may be made by conventional plastic forming techniques and coated on one side thereof with reflective material.

Abstract: A polarization feed is provided for use in a directional antenna under separation of two linearly polarized electromagnetic waves whereby the feed is basically comprised of a tube, one end of which flares into a feed horn configuration and two wave guides are connected thereto, one ending laterally with its axial end at the feed tube while the other one has one side connected to the other axial end of the feed tube under consideration that respective long cross sectional dimensions are 90.degree. rotated with respect to each other as connected to the tube. Appropriate means are provided for obtaining low reflection feeding.

Abstract: An optimized feedhorn comprising a circular waveguide having a corrugated plate disposed around the outside of the aperture of the waveguide wherein the corrugations of the plate are capacitive as to E plane signals. The feedhorn includes a reduced aperture diameter which selectively protrudes beyond the plane of the corrugated plate. The amount of protrusion of the aperture is determined to approximately equalize E and H plane beamwidths and selectively shape the top and skirts of the signal pattern around the center frequency of interest.

Abstract: A compact frequency reuse communications antenna includes two superimposed structures, each including Kevlar honeycomb, fabric face skins on the honeycomb, and a reflector over one of the face skins, the two structures being spaced from one another by Kevlar ribs formed of honeycomb material. The directions in which the ribbons of the honeycomb cores of the superimposed structures extend, and the directions of the elements making up the reflector of the fabric warps are chosen to minimize thermal distortions and RF losses while providing high natural frequency and low weight.