Abstract: An electronically scanned array antenna useful for millimeter wavelength energy is disclosed. The antenna comprises a fully ferrite loaded square or round waveguide having radiating apertures spaced along part of its length. Rf energy is circularly polarized in the waveguide. The phase velocity of the wave is controlled by applying a longitudinal magnetic field to the ferrite to produce a controllable linear progressive phase of the energy radiated from the apertures to form a beam in the desired direction. The phase control is of a latching type using flux drive. The particular structure of the invention enables combining a plurality of branching array elements with a feed element to form an array capable of two dimension beam scanning.

Abstract: The center region of a dual slot microstrip-type antenna radiator "patch" structure is forced to take on a controlled non-zero radio frequency impedance by the provision of a slot formed therein at the center region. By controlling the dimension of such an impedance-matching slot in the radiator patch, a feedpoint connection may be made at the center region of the radiator patch and still achieve matched impedance feed. Because the feedpoint can thus be centrally located within the antenna structure, any spurious radiation which occurs from the feedpoint connection or associated feedlines does not tend to skew the overall or composite radiation antenna of the pattern as much as when such feedpoints are asymmetrically disposed on the radiator patch with respect to the primary radiating apertures.

Abstract: An inverted Cassegrain antenna utilizing polarization rotation. The polarizer-reflector or mirror utilized comprises two or more polarizer-reflector elements joined together around hinges perpendicular to the widening direction required. A sheet comprising parallel metal wires covers the whole of the elements. For each element, a metal film is separated from the sheet by a first dielectric layer. Each hinge is formed, on one side, by the flexible sheet of metal wires which straddles the gap between elements. The other side of the hinge includes a second dielectric layer backed by a rigid metal strip, also straddling the gap. One end of the metal strip is fixed to the metal film of one adjacent element while the other end of the metal strip is in moveable electrical contact with the metal strip of the other adjacent element. The antenna is particularly applicable to multiple function radars.

Abstract: A network having a plurality of network ports includes a plurality of substantially identical, independent components, each one thereof having a plurality of ports, the degree of coupling among the ports of each component being characterized by a predetermined scattering coefficient matrix. A plurality of feed networks is included, each one having: a first port corresponding to one of the plurality of network ports; and, a plurality of second ports each one being coupled to a corresponding one of the plurality of ports of each one of the plurality of components, the degree of coupling among the first port and the plurality of second ports of each of the feed networks being characterized by a predetermined scattering coefficient matrix. The plurality of feed networks and the coupling thereof to the components characterize the network with a scattering coefficient matrix, relating the coupling among the network ports, different from the scattering coefficient matrix characterizing each one of the components.

Abstract: The present invention relates to an arrangement for the omnidirectional orientation of an antenna. The arrangement includes a housing mounted on a fixed mast so that it can rotate around the axis of the latter, and an antenna support mounted on the housing so that it can rotate around an axis perpendicular to the mast. Two adjustment assemblies including a toothed ring integral with one of the elements of the adjustment assemblies and a worm engaged on the toothed ring and mounted immovable in translation on another element of each adjustment assembly, allow the antenna to be adjusted finely in elevation and in the azimuth. The arrangement also includes locking means for locking each of the adjustment assemblies. In the event of the deterioration of the adjustment arrangements associated with the fixing arrangement, the effectiveness of the immobilization is not prejudiced.

Abstract: A lightweight mounting structure combination for small dish antennae is provided. The structure includes an upright mast for supporting the dish antennae. The mast has an upper end for attachment to said dish and a lower end for anchoring to a rigid-type structure. The structure also has a bent strut having a lower end for anchoring to a rigid-type structure and an upper end for attachment to said mast. In addition, a second strut is provided having a lower end for anchoring to a rigid-type structure and an upper end for attachment to said mast. Further included is means for anchoring the respective lower ends of the mast, bent strut and second strut to the rigid-type structure and for attaching the respective upper ends of the bent and second struts to the mast. The means includes a bracket, a threaded bolt having a shank portion for extending through the bracket and respective end, and a nut threaded on said bolt for drawing the bracket and respective end tightly together.

Abstract: A coaxial connector for connection to one end of an antenna comprises a metal shell including a coupling section for coupling the connector to a complementary coaxial connector. A dielectric member is disposed in the metal shell and secured therein enabling the metal shell and dielectric member to rotate relative to each other. A bore extending through the dielectric member has a front section of polygonal configuration along which a contact section of the center contact member extends and a rear section along which a theaded section of the center contact member forms threads in the rear section thereby securing the center contact member in the bore of the dielectric member while the polygonal front section engages a complementary holding member to maintain the dielectric stationary during threading of the threaded section into the rear section. An antenna-securing section of the center contact member extends outwardly from the threaded section onto which an end of an antenna is secured.

Abstract: A vertically polarized array comprised of both bottom fed and top fed conurations having a driven element comprising at least one but, when desirable, two generally horizontal wire conductor segments of a length substantially equal to one half the operating wavelength of the array and with the ends of the half-wave conductor segments being connected to or extending into generally vertical quarter wavelength wire conductor segments. In a bottom fed configuration the feedpoint is at the bottom end of one vertical quarter wavelength conductor segment while in a top fed configuration one vertical quarter wavelength segment comprises a quarter wavelength of coaxial transmission line having one end configured into signal isolation means, comprising a cable choke, while the feedpoint is located at the other end.

Abstract: An improved antenna mesh material is made of gold-plated tungsten wire. Because gold-plated tungsten can be drawn to a very fine diameter (less than one mil) it results in a knit mesh having low mechanical stiffness. It also has high electrical conductivity, thereby enhancing its operation as an antenna reflector up to the higher RF frequencies (EHF). In addition, gold-plated tungsten has both sufficient tensile strength and a low coefficient of thermal expansion which enables it to maintain high reflector surface accuracy for changing thermal conditions.

Abstract: A reactive attitude stabilization system to be carried by a vehicle is provided where a first shaft is pivotally mounted on the vehicle in a normally horizontal relation. A second shaft is supported in horizontal relation at its midpoint by the first shaft and oriented perpendicular to the first shaft. Nonrotating slide bearings support a platform on the second shaft for translation of said second shaft relative to the platform. Resilient members oppose translation of the second shaft relative to the platform in either direction and normally maintain the intersection of the axes of the first and second shafts vertically above the center of gravity of the platform. An acceleration induced shift of the second shaft axially and horizontally relative to said platform causes a torque due to gravity to counteract the acceleration dependent torque.

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: An automotive window glass antenna incorporating in a window glass a first antenna possessing a horizontal part and a vertical part to form a T-shape, a second antenna for phase compensation comprising at least one horizontal antenna wire disposed on one side of the vertical part of the first antenna and connected thereto, a third antenna for impedance matching disposed on the other side of the vertical part of the first antenna and connected thereto, and a feed point connected to the third antenna, said the second and the third antennas being asymmetric with respect to the vertical part of the first antenna.

Abstract: To optimize antenna bandwidth and efficiency in broad-band antenna elements of the planar, multiarm spiral and log periodic types, a conically shaped ground plane characterized by progressively sized circumferential chokes, is arranged on a common axis with the axial center of the spiral or log periodic elements so that the electrical spacing between the excited regions of the log periodic of spiral elements and the ground plane maintains a constant one-quarter wavelength relationship. The progressively sized circumferential chokes on the ground plane cut off the flow of excessive radial currents along the ground plane surface to achieve an improved mix of excitation and reexcitation modes. In one embodiment, the circumferential chokes on the conical ground plane are partially shunted by shunting strips that electrically or capacitively bridge the choke walls to reestablish limited radial currents along the ground plane for sustaining certain desirable antenna modes.

Abstract: A backfire bifilar helix antenna is disclosed having two helically wound conductors made of coaxial cable wherein the two conductors comprise the shield portion of the cable. The coaxial cable of one of the conductors serves as a transmission line for supplying signals to the feed end of the antenna and has its center conductor connected to the shield of the other conductor cable. The nominal input impedance of the antenna may be adjusted to a desired value by conductive surface layers attached to the shield portion of the conductors at the feed end.

Abstract: A tool for indicating the position of a receiving device mounted on a convergent reflector with respect to the focus of that reflector, the tool having a collar and clamp for attaching it to the receiving device and converging, telescoping legs extending toward the reflector to indicate the angular and/or axial displacement of the receiving device from the focus of the reflector.

Abstract: The present invention relates to an antenna arrangement for reducing multipath fades. The antenna arrangement comprises a curved main reflector disposed confocally with one focal point of a subreflector, and a feed arrangement. The feed arrangement comprises at least a pair of feed horns and a selectively movable plate reflector disposed between the feed horns and the subreflector along a feed axis of the antenna arrangement. The feed horns are disposed adjacent each other with the aperture of each of two feed horns covering one-half of the image of the main reflector. By selectively orienting the plate reflector so that one of the two multipath beams arrives with its central ray disposed orthogonal to the aperture of the feed horns, the contribution from each half of this beam received at each feed horn, for a particular frequency band, is equal and can be subtracted from the other half beam signal to cancel its effect without the need for an equalizer.

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 microstrip antenna having approximately an octave bandwidth comprises a planar radiating element disposed approximately coplanar with and in front of an upper ground plane and spaced above a lower ground plane at a distance equal to approximately one-tenth wavelength at the lowest operating frequency (one-quarter wavelength at the upper operating frequency). A thin dielectric layer is disposed on top of the upper ground plane which is coupled to the lower ground plane. The antenna, which is linearly polarized, is fed from the rear by a launcher that is approximately coplanar with the radiating element and mounted above the dielectric layer. Impedance matching means are provided for improved performance.

Abstract: An antenna structure in which two or more microstrip arrays are disposed on op of each other to minimize the required space. The shape of the microstrip elements and the polarization thereof are chosen so that the individual elements radiate only in specific areas along the edges of the elements with the remainder of the element having no appreciable electric field concentration. Because of the operating frequency of a microstrip element is a function of the size of the element, a second antenna of smaller higher-frequency elements may be disposed over a larger lower-frequency antenna such that the higher frequency antenna does not cover the areas of the lower antenna that radiate but lies over only those areas having no appreciable electric fields concentrations. Increasingly higher-frequency antennas can be placed on top of the lower-frequency antennas if the foregoing conditions are maintained with respect to all of the covered antennas.

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.