Abstract: A subreflector of a dual-reflector antenna comprises a first extremity comprising a convex inner surface, a second extremity adapted for coupling to the extremity of a waveguide, and a body extending between the first extremity and the second extremity. The body comprises a first dielectric part having a portion penetrating into the waveguide and a portion outside the waveguide, and a second metallic part comprising a first cylindrical portion, contiguous with the first extremity of the subreflector, whose diameter is greater than the portion outside the waveguide of the first dielectric part, and a second cylindrical portion, adjacent to the first cylindrical portion, extended by a conical portion that penetrates into the first dielectric part. The first cylindrical portion features a flat ring-shaped surface that forms an angle less than 90° with the axis of the subreflector so as to face the primary reflector.

Abstract: A transmitter supporting multiple-input, multiple-output communications is provided. The transmitter includes a signal processor, a plurality of feed elements, and an aperture. The signal processor is configured to simultaneously receive a plurality of digital data streams and to transform the received plurality of digital data streams into a plurality of analog signals. The number of the plurality of digital data streams is selected for transmission to a single receive antenna based on a determined transmission environment. The plurality of feed elements are configured to receive the plurality of analog signals, and in response, to radiate a plurality of radio waves toward the aperture. The aperture is configured to receive the radiated plurality of radio waves, and in response, to radiate a second plurality of radio waves toward the single receive antenna.

Abstract: A front feed reflector antenna with a dish reflector has a wave guide is coupled to a proximal end of the dish reflector, projecting into the dish reflector along a longitudinal axis. A dielectric block may be coupled to a distal end of the waveguide and a sub-reflector coupled to a distal end of the dielectric block. A shield is coupled to the periphery of the dish reflector. A subtended angle between the longitudinal axis and a line between the focal point and a distal periphery of the shield is 50 degrees or less.

Abstract: A shape-memory reflector is provided according to various embodiments. The shape-memory reflector may comprise any of various shapes; for example, the shape-memory reflector may comprise an off-axis paraboloid or a non-asymmetric shape. The shape-memory reflector may include a plurality of panel shape-memory stiffeners and a plurality of longitudinal stiffeners. In a stowed configuration, the shape-memory reflector is stowed with reversing bends in the panel shape-memory stiffeners. In a deployed state, the panel shape-memory stiffeners may be unfolded and/or extended. The reflector transitions between the stowed and deployed states by heating the panel shape-memory stiffeners. Various methods for stowing and deploying the shape-memory reflector are also disclosed.

Abstract: The dual-band antenna is provided. The dual-band antenna includes an impedance matching control element, a first connection part, a first radiation element, a second radiation element, and a ground element. The first radiation element operates in a first frequency band, is connected to the impedance matching control element, and extends along a first direction having an obtuse angle with respect to a longitudinal direction of the first connection part. The second radiation element operates in a second frequency band. The ground element is electrically connected to the impedance matching control element and the second radiation element.

Abstract: A satellite antenna arrangement for a satellite communication system comprising: a reflector for producing a far field pattern with near-zero field strength at a predetermined location to reject unwanted signals from said predetermined location or minimise signal power transmitted to said predetermined location, the reflector having a surface comprising a stepped profile arranged to generate the near-zero field strength in the predetermined location. The stepped profile may comprise a radial step. The location of the near-zero field strength can be steered by moving the reflector or by adjusting the amplitude and phase of an additional beam that covers substantially the same region as the main beam reflected by the reflector.

Abstract: A shape-memory reflector is disclosed along with methods for manufacturing, packaging and deploying the same. The shape-memory reflector may include an elastic reflector material, a shape-memory stiffener, and a plurality of radial stiffeners. The shape-memory stiffener may be coupled with the elastic reflector material in a band that encloses at least a portion of the elastic reflector surface, for example, the exterior of a paraboloid reflector. The plurality of radial stiffeners is coupled with the bottom surface of the elastic reflector material and extends radially from a central portion of the elastic reflector surface toward the outer edge of the elastic reflector surface. The shape-memory reflector may be packaged in a packaged configuration that includes a plurality of pleats within the elastic reflector material and/or the shape-memory stiffener, and the shape-memory reflector is configured to deploy into a deployed configuration (i.e. a paraboloid) by heating the shape-memory stiffener.

Abstract: A shape-memory reflector is disclosed along with methods for manufacturing, packaging and deploying the same. The shape-memory reflector may include an elastic reflector material, a shape-memory stiffener, and a plurality of radial stiffeners. The shape-memory stiffener may be coupled with the elastic reflector material in a band that encloses at least a portion of the elastic reflector surface, for example, the exterior of a paraboloid reflector. The plurality of radial stiffeners is coupled with the bottom surface of the elastic reflector material and extends radially from a central portion of the elastic reflector surface toward the outer edge of the elastic reflector surface. The shape-memory reflector may be packaged in a packaged configuration that includes a plurality of pleats within the elastic reflector material and/or the shape-memory stiffener, and the shape-memory reflector is configured to deploy into a deployed configuration (i.e. a paraboloid) by heating the shape-memory stiffener.

Abstract: The aim of the present invention is a sub-reflector of a dual-reflector antenna comprising: a first end having a junction of a first diameter, adapted for coupling to the end of a waveguide, a second end, having a second diameter greater than the first diameter, a convex reflective internal surface placed at the second end having an axis of revolution, an external surface of the same axis, joining the two ends, a dielectric material extending between the first and the second ends and limited by the internal surface and the external surface, In accordance with the invention, the external surface has a convex profile described by a polynomial equation of the sixth degree of the formula: y=ax6+bx5+cx4+dx3+ex2+fx+g where a is not zero.

Abstract: The approximate radius of curvature of the spherical phase front at the aperture of a transmitting microwave antenna is controlled by an inner section of the aperture attached to the outer section of the aperture by a small number of programmable transducers, thereby controlling the near field shape and power distribution of the transmitted beam.

Abstract: An improved structure for an edge of a disk body of an antenna. The antenna includes the disk body and a side portion. The side portion has a supporting ring and a containing slot surrounding the circumference of the disk body. The supporting ring is on a top of the side portion, therefore the supporting ring of a bottom antenna is reserved in the containing slot of a top antenna while stacking a plurality of antennas sequentially in an order.

Abstract: A flat plate reflective assembly for receiving and focusing incident microwave signals having a wavelength (?), comprising a series of adjacent reflecting surfaces, each having a separate focal points offset from one another in focal length by one wavelength or a multiple of the wavelength. When an incident microwave signal strikes the reflective assembly, each reflected wave is directed to the focal point for the respective reflecting surface and is collected by the LNB. Each reflected wave arrives at the focal point for the reflecting surface in-phase with other reflected radiation. However, spatial resolution of the focal points reduces the deconstructive interferences between the reflected radiation. In another embodiment, the flat plate reflective assembly is configured is configured to reflect incident radiation in-phase such that microwave signals reflected by each reflective surface arrive at a common focal point in-phase.

Abstract: A multi-beam-reflector dish antenna system. Signals from different satellites are simultaneously received using a single compound LNBF module. The antenna dish includes a reflector with N-th order projected aperture and a single compound LNBF module constituting multiple LNBF units. The reflector is formed by projected aperture cutting and surface distortion of the aperture in accordance with the method of analysis and synthesis. In addition to reflecting signals from satellites, it also generates focused waves sharing similar radiation patterns and horizontal gain with incoming waves on the focal plane to be received by the compound LNBF modules.

Abstract: An integral reflector-boom assembly (1) for a deployable antenna includes a facesheet (9) of stiff reflective material and a stiff lattice or grid structure bonded to the facesheet to form a reflector (3) portion of the assembly and a boom (5). Interlocked ribs (13, 15, 17 & 19) are arranged in a pattern that defines an isogrid structure in the reflector portion and at least a part of the boom assembly. Some of the ribs (13) extend in one piece from the reflector portion through the boom portion.

Abstract: An antenna system is provided with an antenna panel 1 which has fine bumps and dips 4 formed on a mirror surface side, which is one of surfaces opposing to each other, by etching, wherein the fine bumps and dips scatter sunlight entering the mirror surface side of the antenna panel 1 to suppress the collection of the sunlight and regularly reflect radio waves having longer wavelength than the sunlight entering the mirror surface side of the antenna panel.

Abstract: A multi-beam-reflector dish antenna system. Signals from different satellites are simultaneously received using a single compound LNBF module. The antenna dish includes a reflector with N-th order projected aperture and a single compound LNBF module constituting multiple LNBF units. The reflector is formed by projected aperture cutting and surface distortion of the aperture in accordance with the method of analysis and synthesis. In addition to reflecting signals from satellites, it also generates focused waves sharing similar radiation patterns and horizontal gain with incoming waves on the focal plane to be received by the compound LNBF modules.

Abstract: A synthesized reflector surface (12) for directing communication signals (27) in a communication system (10) that operates in a plurality of orbital slots and to a plurality of regions (28) within a first coverage area (30) is provided. The synthesized reflector surface (12) includes a plurality of contiguous profile surfaces (40) that form the reflector surface (12). Each of the plurality of contiguous profile surfaces (40) alters the phase-of the communication signals (27) to provide a first gain for a first satellite orbit location (32) and a second gain for a second satellite orbit location (34). The plurality of contiguous profile surfaces (40) directs the signals from the location (32) in a first orientation to the first coverage area (30) or from the location (34) in a second orientation to the first coverage area (30). A method is provided for synthesizing the reflector surface (12).

Abstract: A centrally fed reflector antenna system has an effective reflector surface shaped so that the maximum of the copolar far field lies on the illuminated coverage area corresponding to the far field requirements, and the minimum of the copolar near field lies at the feed system, e.g. at the aperture of a feed horn.

Abstract: In summary the present invention discloses a horn reflect array antenna system and a method for producing a signal using a horn reflect array antenna. The system comprises at least one reflective element illuminated by an incident radio frequency (RF) signal from a feed horn, the reflective element reflecting a portion of the incident RF signal as a portion of a reflected RF signal, and at least one phase shifting device, each phase shifting device coupled to a corresponding reflective element, wherein a beam pattern of the reflected RF signal is altered when the phase shifting element changes the phase of the portion of the reflected RF signal.

Abstract: A parabolic reflector assembly (10) comprising a base member (11) formed of magnetic material and defining a parabolic surface (12), and a flexible magnet sheet (18) carrying a reflective sheet (19) magnetically bonded to the parabolic surface to form a parabolic reflecting surface. A method of manufacturing the parabolic reflector assembly is also disclosed. The parabolic reflector assembly typically may be used as a concentrator is solar energy concentrating apparatus.

Abstract: An antenna includes first and second convex-curved antenna elements, which are connected in series via webs extending in a longitudinal direction of the antenna, such that they form a helical configuration. A further antenna element may extend parallel to the helical configuration. The antenna can be stamped from a single metal part, can be bent into a desired shape, and is particularly suitable for multiband applications.

Abstract: A collapsible conductive material includes a generally mesh-configured, collapsible surface, that defines the intended reflective geometry of an antenna. A distribution of tensionable cords and ties form radial truss elements with a plurality of inflatable radially extending ribs and posts of a support structure. The antenna is fully deployed once the support structure is inflated to at least a minimum pressure necessary to place the ties and cords in tension so that the reflective surface acquires a prescribed (e.g., parabolic) geometry, which is stably maintained by the radial truss elements.

Abstract: An antenna receives beams from telecommunication satellites in geostationary orbit close to the equator. The continuous concave reflecting surface of the reflector of the antenna has an equation deduced from a paraboloid by adding thereto the equation of a correction surface comprising a second order polynomial and a sum of N(2N−1) terms depending on distances between the projection of any point on the reflecting surface and N(2N−1) control points of a grid extending over a plane perpendicular to the plane of symmetry. The angular separation of the primary sources on a circular support with an inclination different from the angle of offset is less than approximately 3° for an aperture of more than 50°.

Abstract: A method for shaping reflected radio frequency signals includes geometrically shaping a reflector surface of an antenna to focus the beam, and reflectively shaping the reflector surface with phasing elements that emulate geometric shaping to configure the beam to a predetermined shape. In the preferred embodiment, the antenna comprises a geosynchronous satellite antenna conveying signals from a wave guide horn to or from a predetermined geographic area on earth. The use of a parabolic-approaching surface of reflectarray phasing elements for shaping the beam substantially improves the beam pattern bandwidth over the performance of previously known shaped beam reflectarrays.

Abstract: A collapsible conductive material includes a generally mesh-configured, collapsible surface, that defines the intended reflective geometry of an antenna, and a distribution of tensionable cords and ties, which attach the reflective mesh to an inflatable support structure. The antenna is fully deployed once the inflatable support structure is inflated to at least a minimum pressure necessary to place the attachment tie/cord arrangement in a tension that causes the reflective surface to acquire a prescribed (e.g., parabolic) geometry. Preferably, the inflation pressure is above the minimum value, so as to allow for pressure variations (drops) within the support structure.

Abstract: A reflector is constituted by a right pseudo-dihedral, a ridge (C) of which is in the form of a portion of a helix so as to provide a calibrator or a beacon.

Abstract: A compact and flat antenna that provides both Direct Broadcast Satellite and local off-air reception. The flat reflector is made of a composite material with multiple reflective radiating surfaces. The multi-stepped reflector combines both diffraction and refractive principals to collimate Radio Frequency signal waves to a short focal point. At the focal point a phase correcting splash plate and lens direct the RF signal through a low loss axis-fed circular waveguide and then to a low noise amplifier. This compact design reduces space, cost and over-all structure, which presents an aesthetically pleasing satellite communication antenna. The antenna aperture includes a VHF/UHF antenna element for reception of local and/or off-air broadcast TV signals eliminating the need and cost to install a separate antenna.

Abstract: A system is described for vertically stacking a plurality of satellite dishes for bulk transport and storage using minimal space. Each satellite dish has a parabolic dish with a stacking rim attached to its outer periphery at an angle of about 125 degrees. The stacking rim has two circumferential support regions on opposite surfaces. When the satellite dishes are stacked vertically, the support regions of the stacking rims abut, leaving a space between the parabolic surfaces of adjacent dishes. This space has the same dimensions as the thickness of the material forming the dishes. The support provided by the abutting support regions also causes the edges of the rims of stacked dishes to be separated by a space so that the dishes can be easily separated when needed.

Abstract: A zone plate for focusing microwave energy is provided comprising a plurality of reflective portions corresponding to zones of the zone plate, each reflective portion reflecting energy .lambda./P out of phase with respect to adjacent reflective portions, where .lambda. is the wavelength of the energy. The reflective portions are positioned in P parallel planes mounted on low dielectric loss sheets and separated by a distance of .lambda./2P such that energy reflected from the reflective portions constructively interfere at a focus of the zone plate.

Abstract: A compact, portable satellite dish antenna system comprises a dish-shaped member having an inner surface that includes a central circular flat area and a plurality of annular parabolically-shaped segments concentric with the central circular flat area for providing a plurality of focal points over the inner surface of the dish-shaped member to thereby improve the signal gathering characteristics of the dish antenna system.

Abstract: A laminated composite shell structure having quasi-isotropic thermal expansion and contraction characteristics and a method for its fabrication. The laminated composite shell structure includes multiple layers of overlapping strips of composite material conforming to an axisymmetric doubly-curved surface. The fibers in the multiple layers are arranged at different relative angular orientations, with the composite strips being shaped to maintain the fibers at a constant relative angular orientation throughout the shell structure.

Abstract: The receiving antenna comprises at least two sectors or sections of paraboloids focusing the radiation onto their axes at points F.sub.1 and F.sub.2 respectively offset by a whole number of wavelengths of the received radiation. Each sector or section is associated with a helicoidal source located in its focal zone and having the same axis as that of the corresponding sector.

Abstract: The invention presents an optimum method and mean for reducing the side robes of microwave antennas whether mounted or through the serrated-roll treatment of their edges. The reduction of side robes leads to the enhancement of the main robe, the suppression of the unwanted electromagnetic interference, the improvement of antenna performance, as well as lowering the size of antenna.

Abstract: The antenna particularly for domestic, collective or community installations, receives plural telecommunication beams and comprises a preferably paraboloidal fixed reflector with an axis of symmetry. At least one grating of annular diffraction members is substantially symmetrical with regard to the axis and is placed parallel to the reflector. The grating defines first and second focal points symmetrical to the axis towards which are susceptible to converge first and second beams directed substantially parallel to straight lines going through the centre of the grating and through first and second focal points respectively. A microwave head can sweep the focal plane along a focal line, or several microwave heads are positioned on a gantry thereby receiving or emitting plural beams, though the reflector is fixed.

Abstract: A compact range system includes a feed antenna offset from the rectangular-aperture paraboloidal reflector. The reflector has blended edges and smoothed corners to reduce contamination of propagated electromagnetic plane waves by diffracted energy. The continuous, smooth surface of the reflector maximizes the purity and uniformity of the plane waves from the reflector.

Abstract: An array fed reflector antenna includes a reflector and a distributed feed array. The reflector has a portion with a dual parabolic shape. The distributed feed array transmits and receives a plurality of electromagnetic energy beams simultaneously, and is positioned adjacent the reflector so that the reflector reflects the transmitted and received electromagnetic energy beams. The distributed feed array is offset from the reflector so that a plane wave formed by the transmitted electromagnetic energy beams reflected by the reflector will not substantially impinge the distributed feed array. The antenna also has a beam switching network which is a hybrid network for selectively actuating separate but overlapping portions of the distributed feed array to produce two transmit elevation beams.

Abstract: A single offset reflector antenna is disclosed which provides .+-.30.degree. of horizontal scanning and 0.degree. to +15.degree. of vertical scanning without aperture blockage, while maintaining high aperture efficiency, and 0.degree. to -30.degree. of vertical scanning with moderate aperture blockage. The sufrace of the reflector antenna is described by a sixth order polynomial equation. Curvature of the horizontal cross-section of the surface taken through its center is determined by a fourth order even polynomial expression with coefficients that are found by a numerical minimization technique. Further terms, including terms of up to sixth order and their associated coefficients obtained by the numerical minimization technique, define the curvature of the vertical cross-sections of the surface to yield a three-dimensional unitary reflecting surface.

Abstract: A multibeam antenna capable of communicating with a plurality of satellites on stationary orbits at the same time includes a single main reflector, and a plurality of primary radiators for radiating electromagnetic waves toward the main reflector. The main reflector is constituted by the same number of partial reflectors as the primary radiators, the partial reflectors being joined to each other. Each of the partial reflectors is defined by a part of a different one of paraboloids which are different in the position of focus from each other. The primary reflectors are located at the positions of individual focuses. A subreflector is disposed between the main reflector and the positions of focuses and made up of a plurality of curved portions and a single flat portion.

Abstract: The antenna has a main reflector (1), a subreflector (4a, 4b, 5a, 5b), and a feed radiator (2) which are all rotationally symmetric about a common axis (10). In a section in the direction of this axis of symmetry (10), the subreflector has the shape of two curves meeting in the axis of symmetry. Seen from the feed radiator, these curves are concave. Each of the two curves has at least one step (6a, 6b) for matching the feed radiator to the transmitter or receiver.

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 frequency selective surface having a fibrous ceramic material body and a metallic grid on a reflecting face thereof. The body is formed by bonding a mass of silicon dioxide fibers together at their intersection points, as with a fusing agent such as boron nitride in a sintering process, resulting in an array of fibers with cellular porosity intentionally distributed through the body to reduce its density. Other types of ceramic fibers can be used either alone or in combination with the silicon dioxide fibers. The grid is attached to the reflecting surface or deposited thereon. The frequency selective surface finds particular utility in satellite microwave communications satellites.

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 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: 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 shield for a satellite earth station located in a dense radio frequency environment. The shield includes a satellite earth station antenna position in a pit. Surrounding the pit is a tear-shaped earthen berm. Positioned on top of the berm is a wall made of a series of modular precast concrete panels specially designed to reduce the diffraction of radio frequency interference over the top of the panels and to minimize the internal reflection of radio frequency interference. The panels each include an inner face of two sets of horizontal slats set at alternating angles. The two sets of slats are designed to attenuate and disperse radio frequency interference in the range of the satellite communication downlink and uplink frequencies. In addition, the present invention includes specially shaped grooves cast into the top face of the panels which attenuate radio frequency interference passing over the top of the wall.

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: A shaped beam antenna of the type comprising a main reflector and a feed horn for irradiating an electromagnetic wave upon said main reflector, the main reflector including, in sectional planes inclusive of a Y-Z plane and planes parallel thereto, a central section and horizontal side end sections adjoining the central section, where Cartesian coordinates are assumed having an origin near the feed horn, a Z-axis extending in a direction of the horizontal center axis of the feed horn, and X- and Y-axes extending in planes perpendicular to the Z-axis.

Abstract: This invention relates to a multi-beam antenna and a method of configuring the same, where the antenna consists of a main reflector, a plurality of horns for exciting the main reflector, and separate sub-reflectors for correcting phase errors of respective beams caused by reflection at the main reflector, or an integrated sub-reflector which is substituted for said separated sub-reflectors.

Abstract: This invention relates to a multi-beam antenna and a method of configuring the same, where the antenna consists of a main reflector, a plurality of horns for exciting the main reflector, and separate sub-reflectors for correcting phase errors of respective beams caused by reflection at the main reflector, or an integrated sub-reflector which is substituted for said separated sub-reflectors.

Abstract: A radar antenna with a collector of microwave energy incident along the main lobe of its radiation pattern, feeding a processor whose principal channel generates a raw output signal, is provided within the effective area of that collector with one or more ancillary radiation receivers intercepting energy from side lobes encumbered by interfering signals from directional jammers. The output signals of auxiliary channels connected to the ancillary radiation receivers are subtracted in the processor, at an intermediate-frequency level, from the raw output signal of the principal channel to produce a useful signal which is fed back to an adaptive cancellation loop in each of these auxiliary channels.