Abstract: A compact collapsible broadband directional VHF antenna is disclosed. The antenna is comprised of radiating elements consisting of rods in a Vee configuration, the rods being incorporated into a mechanism in which a series of insulating links are used to raise the antenna with a low and uniformly applied force. Associated with these are phasing elements physically shortened by capacitive loading.

Abstract: A tuned radio antenna for a frequency agile communication system has a plurality of tuning inductors in series with a short-circuiting switch for each inductor, each switch being formed by a pair or a plurality of pairs of P.I.N. diodes, control means being provided for applying biasing potentials to the diodes to effect switching of the antenna tuning.

Abstract: An antenna mount includes a mounting plate which holds an antenna such as a microwave horn. The mounting plate is connected by a hinge to a baseplate. The angle of the mounting plate with respect to the baseplate is controlled by an adjustable brace extending between the antenna mounting plate and a bracket, allowing adjustment of elevation. The baseplate is pivotally mounted on a mechanical ground allowing independent adjustment of azimuth.

Abstract: The invention relates to multi-mission orbital spacecraft of the kind comprising a platform and several different payloads including several telecommunication antenna feed systems.The problem is to avoid antenna interference, obtain bigger effective antenna aperture, avoid the necessity for replacing main antennae when replacing payloads, and make maximum use of longer platofrm life.In accordance with the invention, the antenna system comprises a common primary reflector which is a permanent integral part of the platform while the feed systems are mounted on the payloads, which may be launched separately, and are assembled with the platform to cooperate with the common platform antenna system in operation.The invention is mainly applicable to multi-mission satellites.

Abstract: The method of repeatably making an antenna coupler for holding a test antenna in a repeatable fixed position on the exterior surface of an aircraft or the like relative to a working antenna disposed within the aircraft. A positive mold is made of the area adjacent the antenna within the aircraft. A temporary RF shielding box is placed over the positive mold and the mold is modified to support the box repeatably in a fixed position. Pins are provided to interact with mounting holes for an antenna. A permanent box to be used as part of the coupler is mounted on the positive mold. A ribbon gasket comprising a plurality of tubular, compressible members of an RF shielding material and having mounting tabs along the length thereof is disposed against the surface of the mold about the peripheral edge. The gasket and the box are interconnected by an epoxy material, including RF shielding means. The coupler is removed from the mold and the antenna is mounted to the mounting holes.

Abstract: A spiral antenna has a plurality of interleaved radiating elements winding outwardly in a spiral pattern about a common axis. The spiral pattern is deformed at outer regions of the antenna to define one or more circumferentially disposed concavities in the body of the antenna. Each concavity is adapted to receive another antenna such as a spiral antenna or horn antenna.

Abstract: Support structure for a solar collector consisting of two sets of bars linked by assembly nodes, a concave triangulated lattice (1) around the central node (10) positioned on the sighting axis (xx'), and a stiffening lattice (2) separated from the concave lattice (1) by struts (3, 6), the bars of the two lattices, positioned in a number of planes (P, Q, R) passing through the axis, constituting rigid half-trusses extending radially from a common central strut consisting of a column (3) positioned on the sighting axis (xx') and carrying at its ends the central nodes (10, 20) of the two sets of bars.

Abstract: An antenna system having a main reflector, a sub-reflector, and a plurality of horns for radiating different frequencies includes a beam waveguide system which cancels cross polarization otherwise inherent in the system. If the antenna system uses a non-rotationally-symmetric sub-reflector the cross polarization caused thereby is cancelled by the beam waveguide system having at least two focusing reflectors and selected parameters. Alternatively the beam waveguide system can be used with a rotationally symmetric and stationary sub-reflector by being positioned to reflect said beam on the axis of the main reflector. Either the horns or the focusing reflectors may be rotatably switched, the other group being stationary.

Abstract: A compact, low-profile broad-banded log-periodic antenna comprises a planar conductor (3) partially sandwiched by but electrically insulated from two substantially parallel spaced-apart ground planes (4, 8). The sandwich extends as far as an imaginary plane (15) that is orthogonal to conductor (3) and to the ground planes (4, 8). Conductor (3) comprises an alternating series of radiating loops (L(n)) and non-radiating transmission-line loops (L(j)). The non-radiating loops (L(j)'s) lie on the ground plane (4, 8) side of plane (15). The radiating loops (L(n)'s) lie on the other side of plane (15). Optional additional ground planes (6, 10) may be employed, in which case they lie in plane (15) and meet one of the primary ground planes (4 or 8, respectively) along a common edge. The length (d) of the loops (radiating or non-radiating), the spacing (D) between loops, and the height (h) and width (w) of the radiating loops (L(n)) are all scaled by a factor (S) which is less than 1 but greater than 0.

Abstract: Multibeam lens antennas are often circular, and utilize propagation in disk-shaped parallel-surface regions. There is phase correction through terms in .theta..sup.2, where .theta. is the angle of an aperture point measured from the boresight direction. In the new designs herein, the lens comprises two portions, each being two closely spaced plates with a dielectric medium between them. One portion is formed as a surface of revolution (cylindrical or conical) with two circular ends, one end being an aperture with element feedpoints coupled to array elements. The other portion is a cap joined to the other end of the first portion. The cap may be a disk or a segment of a sphere. The dimensions and indices of refraction are selected to provide focus points for feed ports, with each focus being for a specific beam direction. The parameters may be selected so that the focus points are within the cap, at the periphery of the cap, or at the aperture. Some of the new designs have phase correction through .theta..sup.

Abstract: The invention relates to a bi-axial support of a rotatable body in a projectile for supporting said body such that it can perform small tilting motions about two mutually perpendicular axes lying in a plane, which is perpendicular to the longitudinal axis of the projectile. The support consists of a spherical or partly spherical bearing body introduced into a correspondingly spherical cup-shaped recess in a projectile-fixed part having the open end directed forwards in the motion direction of the projectile. The spherical bearing body is retained in the recess by means of two pairs of link arms defining two virtual tilting axes for the bearing body and connected to two output shafts such that a tilting motion of the body about the respective virtual axis results in a rotation of the respective output shaft and vice versa.

Abstract: An antenna, suitable for being deployed from an aircraft or other vehicle and characterized by broadband, omnidirectional radiation/reception is provided by a coaxial transmission feed line that is terminated by an electrically conductive ball that is electrically and mechanically connected to an extension of the center conductor of the coaxial line, and by a telescopically adjustable sleeve choke having the end adjacent the ball conductor, electrically bonded to the outer conductor of the coaxial line. The choke is adjusted in length to form a matched counterpoise to the ball radiator.

Abstract: A NAVSTAR satellite has a navigation antenna array beamed toward the earth. A communications antenna array for communicating with other satellites requires a pattern null near the axis and high gain to the sides with minimum losses. This is achieved with a dipole ring array comprising eight elements surrounding the navigation array. The ring has a diameter of 1.1 wavelength, and is fed with equal amplitudes and a third mode phase progression, which produces good circular polarization in the far field. For a different sized dipole ring, there will still be an optimum phase distribution which will give good circularly polarized patterns.

Abstract: A waveguide manifold for monitoring the operation of an array antenna. The waveguide is centerfed and has reflecting terminations at either end. The waveguide output is matched to the waveguide as if non-reflecting terminations were at either end of the waveguide. The waveguide input is a plurality of groups of slots wherein adjacent groups have alternating phase. Adjacent slots in each group have alternating polarity. A standing wave created in the waveguide has a plurality of cells of alternating phase. Each slot is located within one of the resonating standing wave cells. The resulting manifold beam forming characteristic will be temperature and frequency independent over a practical range.

Abstract: A compact antenna feed system for orthogonally polarized RF signals includes a waveguide feed having orthogonally disposed internal ridges, a pair of wave detectors coupled to the waveguide feed to receive orthogonally oriented RF signals, and an amplifier housed as part of the feed system to amplify received RF signals prior to communication of the signals outside the feed system. The system is readily switchable by remote control to receive RF signals in either orientation and angular alignment to the orientation of the incoming signals is easily accomplished.

Abstract: A radar antenna is shown in a first embodiment to have a ground plane and a feed line on opposite sides of a dielectric sheet and a ring-shaped antenna element on another dielectric sheet to form a microstrip assembly wherein such antenna element is capacitively coupled to the feed line. In a second embodiment the radar antenna has a parasitic antenna element on still another dielectric sheet, such parasitic antenna element being in register with the ring-shaped antenna element.

Abstract: An antenna is tuned in separate discrete frequency bands by changing the ctrical length of the antenna. PIN diodes are placed at predetermined locations on the antenna coaxial cable radiating elements. When it is desired to shorten the antenna for a higher frequency band use, the diodes are biased short circuiting segments of the antenna. When the lower frequency band use is desired, diodes are unbiased so that the diodes act like a very small capacitance shunted by a large resistance which is essentially an open circuit permitting the entire length of the antenna to operate.

Abstract: A waveguide manifold for monitoring the operation of an array antenna. The waveguide is centerfed and has reflecting termination at either end. The waveguide output is matched to the waveguide as if non-reflecting terminations were at either end of the waveguide. The waveguide input is a plurality of slots wherein adjacent slots have alternating polarity. A standing wave created in the waveguide have a plurality of cells of alternating phase. Each slot is located within one of the resonating standing wave cells. The resulting manifold beam forming characteristics will be temperature and frequency independent over a practical range.

Abstract: This invention relates to a process and means for rapid microwave imaging using UHF waves transmitted by an antenna toward a body to be scanned. According to the invention, body O to be scanned is placed in front of a transmitting antenna A and various signals forming the various points of the image are analyzed in a collector-unit RC consisting of a diode-conductor panel 1 and a wave-guide stack 2 and are then transmitted to a receiver R.

Abstract: An apparatus for rapidly starting and stopping a conical scan antenna beam in which a feed rotating about a centerline provides a non-conical scan antenna beam during a search mode. When a target is detected a solenoid moves an actuator pin which displaces one end of the feed from the centerline providing a conical scan antenna beam for target tracking.