Abstract: A redeployable, furlable rib reflector which is furlable and unfurlable between a first stowed position and a second deployed position. The reflector includes a hub assembly having spaced apart top and bottom plate members adapted to receive an antenna feed assembly mounted thereon and a plurality of attachable modular rib assemblies spaced about a periphery thereof. Each modular rib assembly includes a rib member for supporting a metalized mesh reflector surface attached thereto, a channel section base member, and a hinge assembly for pivotally connecting the rib members to their respective channel section base members. The channel section base members, in turn, are attachable between the top and bottom plate members of the hub assembly and also form a portion of the peripheral wall of the hub assembly.

Abstract: A composite antenna and method for constructing same is disclosed. The composite antenna has a grid comprised of electrical conductors woven into the warp of a resin reinforced cloth forming one layer of the multi-layer laminate structure of the antenna.

Abstract: An in-service reconfigurable antenna reflector having a rigid support structure, a deformable reflective surface having radio reflection properties and actuators operating on the deformable reflective surface to deform it. The reflective surface is elastically deformable with stiffness in bending and the actuators operate at control points of the deformable reflective surface, transversely thereto.

Abstract: Dielectric body 20 has a back surface 18, a surface of revolution about an axis 9-9. Back surface 18 has the form of a primary reflector of an antenna for transmitting or receiving microwave or millimeter wave electromagnetic radiation. A layer 15 of electrically conductive material is in contact with back surface 18. Dielectric body 20 also has a dome 23, a coaxial surface of revolution. A layer 25 of electrically conductive material is in contact with dome 23. A horn 40 fits on a protrusion 17 of dielectric body 20. Protrusion 17 aligns horn 40 on axis 9-9. The axial dimension of dielectric body 20 maintains the proper spacing between horn 40, conductive layer 25, and conductive layer 15 to enable the assembly to function as an antenna system. In the configuration shown, conductive layer 15, in contact with surface 18, forms a paraboloidal primary reflector. Conductive layer 25 , in contact with dome 23, forms the concave ellipsoidal secondary reflector of a Gregorian antenna system.

Abstract: In optical, microwave, acoustical and other wave fields diffraction spreading and loss of gain is countered by giving the wavefront approaching an aperture a bevelled lip or edge, whereby the radiation spreading inwards from this edge prevents the outward diffraction spreading of the field, and where any aberrations resulting from the de-diffraction process are corrected by methods analogous to those used to correct for spherical aberrations, the result of these adjustments being to cause a field such as that emitted by a lens or laser, to emerge free from diffraction spreading, gaining in resolution beyond the diffraction limits.

Abstract: A low sidelobe reflector for improving the test zone performance of compact ranges by shaping the edge serrations of the range reflector. The serrations provide a means for synthesizing desired illumination function tapers at the transition region near the edge of a reflector to provide low edge diffraction. Serrations with length greater than ten wavelengths and with a flower petal shape produce the least diffraction of energy into the quiet zone.

Abstract: An antenna apparatus includes a power converting section which receives microwave energy and converts it to DC power. An actuator for folding/unfolding a mirror-supporting member and an actuator for adjusting the configuration of an antenna reflection mirror are driven and controlled by the DC power supplied from the power converting section.

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: 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: A shaped beam antenna system which provides a desired shape of beam, comprises a reflector and at least one primary radiator located essentially at focus of said reflector. Reflection surface of the reflector is a dense set of parabolas in which vertexes of said parabola shift on a predetermined locus which is preferably a three dimensional space curve, but not a plane curve. A second feature of the shaped beam antenna system is the primary radiator which is composed of a plurality of primary radiators positioned closely to each other.

Abstract: A collapsible, dish shaped assembly, for example, for use with a satellite. The dish shaped surface is assembled from two sets of rigid panels. The first set of panels is rotated into position on hinges, which attach the panels to a base. The second set of panels is then rotated into position, also on hinges at the base, such that the second set of panels fill in the spaces between the panels of the first set. A latch connects each pair of adjoining panels. The latch comprises a protrusion which slides into a corresponding cavity. The resulting latch is resistant to lateral force. The latching process is facilitated by magnetic forces, which also add to the final latching force. The latches can be disengaged by jacking screws.

Abstract: A wire carrier clip installable onto a dish antenna after the antenna is up and which clip has a slotted leg which will install to the antenna by slipping between the rib and a washer on the back side rib bolt of the antenna and further including a clamping leg with which to sandwich the lead wires between the wire carrier clip and the antenna rib.

Abstract: An antenna system includes a reflector grid which reflects signals which are within the operative frequency range of the antenna and passes received signals of higher frequency. An absorber is placed proximate to the reflector grid to absorb signals which are passed by the grid. A second reflector located proximate to the absorber reflects signals back through the absorber such that signals reflected by the antenna system are twice attenuated by the absorber.

Abstract: A microwave antenna has a circularly symmetrical reflector made of a material having a liquid phase and a solid phase, with the reflector being obtained by centrifuging the material while in its liquid phase and then allowing it to pass into its solid phase. This results in a convex paraboloidal reflector face having a very high degree of surface accuracy. When housed inside a microwave absorbing ring connecting the reflector face to a microwave-transparent window and used with a suitable source held at a predetermined focus position between the reflector and the window by means of microwave absorbent triangular struts, the antenna demonstrates improved radio and mechanical properties. Alternately, the centrifugally cast convex paraboloidal reflector may be used as the main reflector in a hybrid Cassegrain optical system in which the subreflector has a "conformed" non-paraboloidal surface that is machined from a solid piece of material.

Abstract: A reflector comprises a fiber reinforced plastic plate having a concave shape, a reflecting membrane uniformly formed on the concave surface of the fiber reinforced plastic plate, and a support for anchoring the plate to an immovable.

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 paraboloidal antenna system is disclosed which is segmented. Each segment is attached to a back up structure at three points, and is capable of linear normal motion at these points. The segments can be individually adjusted so as to conform to the true paraboloidal surface after the backup structure has been deformed. The adjustable attach points include digitally-controlled actuators. A laser reference system is used to detect deviations from the true paraboloidal contour. The laser beam is split to set up two sources along the paraboloid axis, and the ensuing hyperboloidal fringe pattern is of circular symmetry. Sensors determine the number of fringes lost or gained as the backup structure deforms. This data is used to guide the actuators to correct for the deviations.

Abstract: A process for manufacturing a parabolic antenna, which comprises arranging, in an injection mold beforehand, a thin sheet comprising a film layer having good weather resistance and a radio-reflecting layer coated with said film layer, and heat-plasticating a pellet-type thermoplastic resin composition with an injection molding machine to inject into the mold, whereby the parabolic antenna is integrally molded, said pallet-type thermoplastic resin composition comprising a fibrous inorganic filler which has a length substantially the same as a thermoplastic resin pellet and arranged approximately parallel to the longitudinal direction of said pellet.

Abstract: A method for cancelling or minimizing the effects of diffraction in wave fields in a wide range of imaging instruments such as telescopes, radar, cameras, ultrasound imaging devices and others, or from laser beams, is described, based on the premise that diffraction is associated with the bending of the energy streamlines of a field, so that such cancellation or minimization of diffraction effects is accomplished by shortening the optical path length normal to the aperture systematically by a function D(x) which has the general form of a superellipse with a minor axis of L and a major axis of A/2, where L is the wave-length of the wave-field, and A is the width or diameter of the aperture, so that the bent streamlines of energy flow near the aperture edge are straightened and the resulting diffraction standing wave pattern is cancelled.

Abstract: Tapering the surface current density near the edges of a parabolic reflector antenna lowers the sidelobe level of the reflector. The current density is tapered by placing tapered resistive edge loads on the reflector for gradually decreasing the conductivity from the center of the reflector to the edge.

Abstract: A splined radial panel solar collector structure approximates compound curvature surfaces by a three-dimensional arrangement of compactly stowable flat reflective panel segments mounted on a collapsible, space-deployable support structure of linear components. The support framework is formed of an umbrella-like framework of radially-extending ribs, struts and cords which deploy away from a central hub to form a system of radial trusses. A semirigid reflective surface structure is divided into sections of radial panels which are supported and shaped by an arrangement of radially tensioned flexible tape members aligned with the ribs. Connecting ties between the tapes and the ribs cause the tapes to assume a catenary curve. The ribs and flexible tape members are bridged circumferentially by sets of cords and ties to which the panels are joined. These cord and tie pairs place the panels in bending to effect a "splined" approximation of a parabola in the radial direction.

Abstract: The antenna system is provided with at least one active radiation source (1) and a reflective surface (2), which is located in at least one part of the radiation (3) generated by the active radiation source (1). The reflective surface (2) is provided with a number of independently adjustable plates (2.j) for generating at least one radiation beam. The antenna system may be provided with means (4) to independently adjust the plates (2.j) for the purpose of (dynamically) orientating the antenna beam.

Abstract: The invention relates to a parabolic antenna reflector. The reflector is comprised of two electrically conducting metal layers (2, 4) which are separated by a dielectricum consisting, for instance, of polypropylene plastic. For the purpose of eliminating the edge currents which occur in the signal receiving and signal transmitting metal layer of the reflector, the reflector is constructed to form a capacitor, wherein the insulating layer (3) is given a thickness such that in conjunction with the dielectric constant of the selected insulating material the side lobes, created by the edge currents, are at least substantially eliminated.

Abstract: A mirror or antenna apparatus having individual petal segments, each of a complex shape, mated with a central hub assembly. Registration pads are provided on the hub assembly to align the petal segments with respect to the hub and each other. Electrical actuators provide fine tuning adjustments in the order of microns.

Abstract: A pair of reflector "skins" which are typically thin metal sheets of the order of five feet by eight feet are placed side by side on the bed of a fixture, this bed having a predetermined size and a contour which is typically parabolic. Longitudinal rib members having a "Z" cross section and the same contour as the bed are placed in the fixture on top of the sheets in spaced relationship to each other and running along the longitudinal extent of the sheets. These ribs are secured in position by means of clamps which press the ribs securely against the sheets so that the entire surfaces thereof are held in mating engagement with the fixture bed so that they assume the contour thereof. The ends of the "Z" cross section ribs are secured to each other by means of gussets and clips. The runners of the ribs which abut against the sheets have a series of small holes spaced therealong.

Abstract: The invention is an electromagnetic wave reflector for an antenna and its production method. The wave reflector comprises a rigid curved support provided with a convex front face coated with a heat-insulating paint, a metal fabric suitable for reflecting the electromagnetic waves and covering the paint, hook and loop strip type fixing means secured to the rear face of the support ensuring that the fabric is maintained on the support, and a thermal extra-insulating material situated on the entire rear face of the support, said extra-insulation material being kept in place by adhesive polyimide strips.

Abstract: An improved anti-icing and de-icing system is provided for reflector-type microwave antennas having a paraboloidal reflector and an associated feed horn for launching microwave signals onto the reflector and receiving microwave signals from the reflector. The improved system comprises a non-conductive, insulated enclosure forming an enclosed cavity adjacent the rear side of the reflector, and a radiant heating system disposed within the enclosure for heating the rear side of the reflector with radiant energy, whereby the air in said cavity is in turn heated by heat transferred to said air from the rear side of the reflector. The radiant heating system comprises at least one infra-red heating source, and is supplemented by a highly reflective mirror coating disposed on the inside surface of the insulated enclosure behind the heating source to direct the radiant energy emanating from the back of the heating source of all regions of the reflector.

Abstract: An array of reflectors of electromagnetic waves comprising a plurality of trihedral reflectors (10 to 17) arranged about a vertical axis (21) with each reflector orientated about its major axis (22) so that the plane bicseting the angle between two panels (18) is vertical and with adjacent reflectors turned through 60 degrees about their major axes (22) relative to one another, characterised in that the reflectors (10 to 17) are tilted relative to said vertical axis (21) of the array with the adjacent sides (37) of adjacent reflectors diverging so that the major axes (22) of the reflectors are directed from the vertices (19) at the required angles of elevation. Preferably, the horizontal sides (24) of alternate reflectors (14 to 17) at the top terminate closely adjacent to corners of intermediate reflectors (10 to 13). The sides (37) of adjacent reflectors diverge towards the bottom to form triangular gaps (38) therebetween.

Abstract: A construction for shielding an item against interference from a microwave radio frequency radiation is disclosed, having a wall structure adapted to minimize radio frequency interference in the vicinity of an antenna. The wall is composed of a plurality of modular wall panels, each having a layer of electrically conductive materials that substantially reflects interfering electromagnetic microwave signals. The wall structure includes a top construction creating a thin, horizontal gap in the conductive material at the wall's top that acts to control diffraction over the wall. In the preferred embodiment, the layer of electrically conductive material is a mesh of expanded metal embedded in the wall modules. The gap comprises the space between the top of the mesh and a pair of vertically adjustable metal strips mounted on the wall. In the preferred embodiment, the wall panels are precast concrete that may be horizontally positioned with a joint allowing up to 180.degree. of relative movement.

Abstract: An antenna array for receiving dual polarized electromagnetic waves, comprised of a first thin-film printed circuit rectenna having a plurality of linear half-wavelength dipole antennae oriented in a first direction for receiving a first component of the dual polarized waves, and a second thin-film printed circuit rectenna parallel to the first rectenna, having a plurality of linear half-wavelength dipole antennae oriented in a second direction for receiving the second orthogonal component of the electromagnetic waves. A reflector screen is disposed parallel and behind the second rectenna, for reflecting incident electromagnetic waves transmitted through the first and second rectennae back to the first and second rectennae for reception thereby.

Abstract: A parabolic antenna dish has a circumferential reinforcement flange portion defined by a ridge line which is devoid of air holes and a mesh plate portion integrally connected to the inner periphery of the reinforcement flange portion, the mesh plate portion having as many air holes as possible formed in a region which is not smaller than 80% in terms of the radius of the radiowave reflecting surface.

Abstract: A foldable and deployable antenna reflector includes a central panel having along its circular periphery a circular-sawtooth shaped contour with ramplike edges separated by radial cut backs and a plurality of similar, rigid segments, each having a foot edge are respectively hinged by means of a single hinge axis to the ramplike sawtooth edges.

Abstract: Antenna reflector mounting system for rapidly supporting reflector segments in precise alignment. A multi-faceted hub member is provided, each face of the hub member defining a rectangular opening of a cavity. A rod is located at the base of each cavity, supported between two walls thereof. A tongue member connected to the narrow end of an antenna segment is inserted in the cavity. The tongue member has a portion extending out from the connected antenna segment and downwardly at an angle. Once the tongue member is inserted over the rod, the distant end of the segment may be rotated vertically. Rotation of the tongue member about the rod pulls the connected antenna segment into alignment with the hub member.

Abstract: A radio-frequency reflective surface is made of a fabric woven from a yarn having an effective coefficient of thermal expansion of substantially zero over a useful temperature range. The yarn comprises a metallic filament around which non-metallic rovings are wound. The coefficients of thermal expansion of the filament and the roving material are related to each other so that mechanical strain thermally induced in the filament by changes in temperature is counteracted by mechanical strain thermally induced in the rovings. Intermodulation products at yarn intersections of the fabric are substantially zero.

Abstract: In a microwave antenna of light weight and small bulk consisting of a reflector and a mirror, the reflector is constructed of vertical combs, horizontal combs and oblique combs. The vertical combs have a pseudo-random distribution with respect to a central comb. The reflector structure has both a shaping function and a supporting function.

Abstract: A method is provided for manufacturing a parabolic reflector antenna carried by a parabolic support made from an appropriate insulating material.

Abstract: A space deployable solar energy concentrator is formed of a dome-shaped arrangement of compactly stowable flat panel segments mounted on a collapsible, space-deployable support structure of interconnected linear components. The support structure is comprised of a plurality of tensioned, curvilinear edge strips which extend in a radial direction from a prescribed vertex of a surrounding umbrella-like framework of radially extending rib members. Between a respective pair of radially-extending, curvilinear edge strips an individual wedge-shaped panel section is formed of a plurality of multi-segment lens panel strips each of which is supported in tension between the pair of edge strips by a pair of circumferentially extending catenary cord members connected to a pair of ribs of the surrounding umbrella-like framework. A respective lens panel strip is comprised of a plurality of flat, generally rectangular-shaped, energy-directing panels arranged side-by-side in the circumferential direction of the dome.

Abstract: A method of sectioning an antennae reflector without distorting the shape of the reflector surface. The reflector is supported in a substantially relaxed state so that only its internal residual stresses determine its shape. A plurality of beam pairs are attached to the outer surface of the reflector and are used to mark the corresponding curves along which the reflector is to be sectioned. When the cut lines have been marked so as to be visible on the inner surface of the reflector, the reflector is then cut along the cut lines marked on the inner surface thereof to section the antennae for transport and storage.

Abstract: Two reflecting surfaces (102, 104) pass through each other at an intersection line (450) lying in a plane of symmetry (106). The two surfaces share a common aperture (101) and the surface contours of the two surfaces are preferably mirror images of each other and are arranged such that the respective two foci (110, 120) of the two surfaces are equidistant (108) from the center of the shared aperture and offset from each other in equal and opposite directions (109a, 109b) from the plane of symmetry.

Abstract: An antenna reflector material for electromagnetic waves is comprised of knitted strands of fine diameter graphite filaments, which have been individually coated with a stress absorbing layer (e.g. a thin metallic or dielectric cladding). Because of the stress absorbing coating, the graphite fibers, which, by themselves, are inherently brittle and unable to tolerate substantial changes to their bend radius profiles, are able to be successfully knitted into a tricot mesh configuration and thereby yield an antenna surface material that possesses a near-zero coefficient of thermal expansion and a sufficiently low in-plane mechanical stiffness. After the tricot knit graphite mesh material has been formed, the cladding layer may be removed (e.g. by heat or chemically dissolved), without affecting the mechanical properties of the graphite strands of the tricot knit.

Abstract: A method of assemblying an antenna having an interlocking support structure with interlocking nodes, and a meshed radiation mirror includes positioning the support structure in a horizontal position, placing the mirror over the horizontally positioned support structure, and pushing glue through the meshes of the mirror to adhere the meshes to adjacent edges of the interlocking support structure. A second embodiment positions a mold in a horizontal position, the mold having a surface form corresponding to a predetermined form of the antenna mirror. Then, the mirror is positioned on the mold surface form. Glue is placed on the edges of the support structure, and the support structure is then deposited on the mirror with the glued edges contacting the mirror. To assemble the support structure, molds are placed around each and every interlocking node. Glue is then forced into the mold to secure the interlocking node.

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 non-furlable paraboloidal radio frequency reflector (10) is formed of a mesh-like flexible reflective surface (18) supported by a central hub (12) and a peripheral rim (14). The hub and rim are interconnected by flexible spoke-like structural cables (16, 24) acting in tension to establish the desired spatial relationship. Reflector surface-positioning cables (20, 26) are secured at their ends to the hub, rim or structural cables and are further secured to the reflector surface at points of intersection (22) therewith intermediate their ends to thereby establish an approximation of the desired curved shape of the reflector surface.

Abstract: An antenna (10) and method for fabricating the antenna (10) includes an inner panel (12) with a curved inner receiving surface (14) and an outer panel (16) in coextensive relationship to one another. A plurality of strips (20) having undulations (22) are positioned between the inner (12) and outer (16) panels for interlocking the panels (12, 16) together in predetermined positions to define a composite antenna (10) of substantial strength to present the inner surface predetermined close tolerances over the surface thereof. The undulations (22) of the strip (20) include platform portions (24) for engaging the panels (12, 16) and straight angulated portions (26) interconnecting the platform portions (24). The strip (20) includes raised ribs (30) in the straight portions (26) and hinge portions (28) between the straight portions (26) and platform portions (24) to allow the lateral extent of the strip (20) to increase as the thickness of the strip (20) between the panels (12, 16) is decreased during fabrication.

Abstract: Plastic-made parabola antennas are improved to get more wave gain in the process of manufacture thereof where a wave reflector material is embedded in other molding materials so as not to cause dislocation thereof during thermoset-molding.

Abstract: A reflector for a circular polarization antenna is described, comprising(A) a thermoplastic resin layer having a thickness of from 5 .mu.m to 5 mm or a coating layer having a thickness of 5 .mu.m to 1 mm and good weather resistance;(B) a metallic layer having a thickness of from 5 .mu.m to 1 mm; and(C) an inorganic filler-containing thermoplastic resin layer having a thickness of from 500 .mu.m to 15 mm and an inorganic filler content of from 10 to 80% by weight.

Abstract: A device to focus to a point parallel electro-magnetic or sound waves, eg a solar power station, that consists of a reflector curved in one direction to a parabola, that reflects incoming waves onto a second reflector which is also curved in one diection to a parabola. The two reflectors are so placed so as to concentrate the incoming parallel waves to a point focus. The second reflector, unlike similar devices, is so mounted that its focal line makes an acute angle to the plane of symmetry of the first reflector. The device may be mounted on a mechanism to allow the device to track the source of energy, eg in the case of a solar power station the sun. The device can be mounted so that as it tracks the source of energy the focal point remains stationary. The operation of the device can be reversed to create outgoing parallel waves of energy from a point source.

Abstract: An antenna reflector is disclosed having a laminated reflector surface bonded to a rigid molded support structure. The reflector surface is thermoformable and has at least one metallized layer that is "sandwiched" between two plastic layers. The forming of the antenna reflector is accomplished in a single molding operation.

Abstract: An apparatus and method for making paraboloidal surfaces for example for paraboloidal reflector antennas. The apparatus and method provides a rigid annular clamping ring of sufficient rigidity to provide even distribution of clamping forces, to clamp a disc-shaped sheet on a table so that the sheet may be pneumatically deformed while held in position to prevent inward slippage of the sheet during the deforming process.