Abstract: An array antenna can control directions of beams by phase-shifting signals received and/or transmitted by a plurality of antenna elements. When the antenna elements are arranged two-dimensionally, sidelobes and beamwidth are determined according a distance between two adjacent antenna element columns. The distance between the adjacent columns can be reduced by arranging the antenna elements in a staggered manner, thereby suppressing the sidelobes, and enlarging the width of beams around an XEL axis. A stabilized antenna system controls the direction of the array antenna and beam directivity by compensating for inclination of a moving platform, so that the array antenna can always track a satellite reliably.

Abstract: A microstrip patch antenna structure is disclosed having increased bandwidth and reduced coupling while maintaining low profile capabilities. The structure includes a support member having an isolating recess in which an electromagnetically coupled patch pair of antenna elements is positioned, the upper element being substantially flush with the surface of the support member surrounding the recess. To enhance isolation of the elements, the recess walls and the support surface are preferably electrically conductive and connected to ground. Also preferably, the lower element is connected to a microstrip transmission line, coplanar with the lower element and suspended within an isolating channel through the support member. In one aspect of the invention, a transition means is interposed between the transmission line and a connector, which connects the support member to a transmitter/receiver, to permit relative rotation therebetween.

Abstract: An integrated antenna system for signal error tracking and correction capable of performing a mechanical conical scan. The mechanical conical scan imposes a modulation upon a received RF signal. This modulation is in turn imposed on an AGC circuit in the receiver of the antenna system, which modulates the AGC signal of the receiver in accord with the modulation imposed on the RF signal by the conical scan. This modulated AGC signal is compared in a detector circuit to a reference sinusoidal signal generated by a local oscillator in the system. This detector circuit outputs an error signal which is added to a reference sinusoidal signal which in combination drive an actuator. This actuator is responsible for imparting nutative motion to the antenna, for the purposes of producing the conical scan pattern.

Abstract: A receiver and antenna drive gear unit provide optimal mechanical and electrical pointing of the antenna dish at each of the satellite orbiting in geo-synchronous fashion above the equator, the receiver having the capability of calculating and initially pointing the antenna dish at each of the satellites, and then providing peaking routines under operator control to maximize signal strength. The antenna drive gear unit utilizes a separate motor for each of the azimuth and elevational directions and utilizes circular ring gears and a spur gear to drive the antenna, thereby providing much more accurate and repeatable monitoring and positioning of the antenna unit over extended usage.

Abstract: A radiating element comprises a groundplane, a dielectric layer and a conductive pattern comprising a folded dipole (20, 21), a feed line (18, 19) for the dipole and a plurality of closely spaced directors (22), all lying in a common plane parallel to the ground plane. An array of such elements with a suitable feed network provides a flat antenna with a squinted beam. The squint angle can be adjusted by adjusting the phase delay between columns of elements. The beam can be steered by selection of the appropriate squint angle and by rotationally adjusting the antenna in its own plane. The antenna is suitable as a less obtrusive alternative to a dish antenna.

Abstract: A seeker head for a target pointer/tracker and the like, the head comprising a rigid mounting plate, an optical seeker for receiving a target signal, the seeker having a longitudinal axis, a joint proximate the longitudinal axis for securing the seeker to the mounting plate with freedom for reciprocal movement about at least two pivot axes perpendicular to the longitudinal axes, an eccentric driving element mounted on the mounting plate for selectively engaging the seeker to move the seeker about the pivot axes, and a controller for controlling operation of the eccentric drive element.

Abstract: A satellite antenna drive mechanism which includes a drive gear housing for reciprocally driving a satellite antenna dish. Generally, the satellite dish is supplied with a retaining bracket to which a U-shaped bow screw is mounted. The bow screw threadably engages the drive gear housing such that rotation of the drive gears causes a corresponding movement of the bow screw and the dish. The drive housing includes three meshed gears which cooperate to drive the bow screw. A first gear drive is connected to drive means for manually or mechanically driving the gears. An intermediate gear connects the first gear to a third internally threaded gear which receives the bow screw of the antenna dish. This third gear drive is positionally captured between the wall plates of the housing yet is free floating within the housing to provide smooth travel of the bow screw through the drive housing.

Abstract: An apparatus for stopping a rotating antenna shaft at a distinct position intermediate two end stop positions 23, 24. Paddle 12 on the rotating shaft 21 cooperates with intermediate stop assembly 26 to arrest bi-directional shaft rotation at an intermediate point when such stopping is desired, the intermediate stop assembly being activated by springs 38, 39 and deactivated by action of solenoids 30, 31.

Abstract: A conversion system for a controller for an antenna rotator which includes circuitry for generating an analog signal which varies as a function of the angular position of the antenna. The conversion system includes circuitry for converting the analog signal to a corresponding first digital signal representative of the angular position of the antenna relative to a first reference heading of the antenna. The conversion system also includes storage circuitry having a prestored table of digital values of angular positions of the antenna relative to a second reference heading of the antenna and which in response to the first digital signal produces a second digital signal corresponding to one of the prestored digital values, the second digital signal thereby being representative of the angular position of the antenna relative to the second reference heading. A digital display system and controller for an antenna rotator are also disclosed.

Abstract: An antenna array for receiving microwave signals is provided that is particularly designed for use in television receive only (TVRO) satellite earth stations. The array comprises a plurality of identically-directed microwave antenna elements arranged in a plane perpendicular to their common primary receiving direction. Each antenna element includes an integral low-noise amplifier (LNA). Outputs of the LNAs are combined to produce a composite output signal which provides maximum response to microwave radiation arriving from the common primary receiving direction of the elements and null responses to microwave radiation arriving from particular other directions. The array includes means for rotating the elements about an axis parallel to the common primary receiving direction. Such rotation effectively adjusts the angle between the primary receiving direction of the array and a null-response direction disposed in a plane perpendicular to the plane of the array.

Abstract: An antenna system wherein the feed assembly is rotated to provide spatial polarization stabilization with respect to vehicle movement so that orthogonal polarizations can be used simultaneously.

Abstract: A polar mount for a satellite dish antenna has the flattened ends of three metal tubes bolted together to form a triangular base having three corners. Three tubular leg members have their corresponding lower flattened ends joined to the respective corners of the base. One leg member constitutes the polar axis shaft. The other two leg members are telescopic and adjustable in length. The upper ends of the two telescopic leg members and the upper end of the polar axis shaft are connected at a common point to create a pyramid-shaped structure. Brackets having bearings mounted to the outside back of the dish and the polar axis shaft extends through these bearings along an axis aligned with a diameter of the dish. The polar axis shaft is at an angle with respect to horizontal corresponding to the degrees of latitude at the antenna location. A tangent to the dish axis is at a declination offset angle relative to the polar axis shaft. The dish rotates on the polar axis shaft through a look angle.

Abstract: A segmented phased array antenna system for scanning two different ranges of directions with a single set of antenna elements. The system comprises a plurality of segments (40), each of which has a plurality of antenna elements (48) mounted therein. The segments are mounted by support means (42, 44, 46) such that each segment is movable between first and second positions. In each set of positions, the antenna elements are operated as a conventional phased array radar system. The antenna system may be longitudinally mounted along the upper surface of the fuselage of an airplane (10) to provide side-looking radar coverage to both sides of the airplane.

Abstract: A folding antenna for use in a satellite communication system comprises a box having a base (1) which forms the supporting structure for the antenna. A main reflector (16) is mounted on a platform (11) to which it is pivotted about a first axis (14). A sub-reflector (26) is pivotted to the main reflector about a second axis (21). By pivotting the sub-reflector and the main reflector downwardly they can be stowed into a position close to the base (1) and the lids (8) of the box closed to protect the system during transportation.

Abstract: The present invention relates to a conical scanning process in a radar antenna.The antenna comprises a principal parabolic reflector (1) and a primary rear-feed source (2) fed by a circular waveguide (3) and displaced with respect to the focus of the parabolic reflector (1). The conical scanning is produced by the rotary movement of the parabolic reflector (1) about the source (2), the said source (2) and the circular guide (3) remaining fixed.The present invention is applicable to tracking radars operating in the millimeter waveband.

Abstract: A cylinder with one end convex, upon said end a disk with a hole in it sits upon it to act as a pivoting mounting plate; stretched nitinol wires are strung down the sides of the cylinder from the edge of the disk to the opposite end of the cylinder rim edge. Each wire is fed an independent voltage to cause length wise contraction of the wire. A computer harmonized actuation of the contractions and relaxations of the lengths of the nitinol wires causes the attitude of the disk mounting plate to change.

Abstract: An antenna with pseudo-toric cover for transmitting and/or receiving a microwave, comprising principally an array transmitting a microwave towards a first reflector in the form of an elliptic or parabolic skull cap, whose concave side is turned towards the array and which reflects the energy towards a second reflector in the form of a concave ring, whose center is occupied by the array and whose concavity is turned towards said first reflector. The reflector is preferably supported by a radome.

Abstract: In an electronically scanned phased array capable of operating at millimeter wavelength frequencies, phase control is implemented through the superposition of orthogonal phase functions via a distributed mixing process at IF frequencies. When the elements of the array are replaced by mixers, and the distribution network operated at LO and IF frequencies, the number of phase shifters required is reduced from M.times.N to M+N and lower frequency technology is used.

Abstract: An improved latch assembly which operates with a phased array radar antenna to fixedly retain the radar antenna in any one of several predetermined positions. The latch assembly comprises an elongated body member having a leading end section tapered to interfit into the detent means without jamming, a wedging member having a tapered wedge-like configuration which slidably interfits with the gradually tapered ledge of the body member, and a controllable spring-loaded actuating means operable to move the elongated body member and the wedge member into locking engagement with a predetermined detent and then to move the wedging member an additional small distance toward the predetermined detent, this causes the wedging member to be forced laterally an amount sufficient to contact the sides of the housing to effect a controlled wedging of the latch assembly in the housing to prevent any rotation of the radar antenna because of undesired clearances between the elongated body member and the housing.

Abstract: An antenna mount for aiming a parabolic antenna towards a geosynchronous satellite characterized by four, pivotal sub-assemblies, each of which is rotatable around its own axis. The mount can be quickly adjusted to point the antenna at a particular geosynchronous satellite, or may be caused to sweep across the satellite belt in a scanning manner. The antenna mount can be attached to a support post of virtually any orientation ranging from vertical to horizontal.

Abstract: A millimeter wave dual beam line scanning antenna integral with a tunable solid state oscillator is disclosed. The antenna provides two fan-shaped beams from opposite faces and when the antenna is rotated, a roughly conical shaped scan obtains. Furthermore, variation of the oscillator frequency causes a variation in radiation angle and provides two line scanning beams from opposite faces.

Abstract: A mechanically positioned phase steered transfer lens which is illuminated y a fixed collimation lens. Wide angle scan is accomplished by tilting the movable lens and electronically scanning the beam to the desired angle. The mechanical motion minimizes the required electronic scan angles, thus minimizing the number of phase shifters required.

Abstract: A radar system for continuously displaying target returns on a conventional television receiver. The radar includes a console connected to a rotating scanner unit through conventional slip rings. The scanner unit contains a radar antenna coupled to a receiver and transmitter, and a power supply generating a multitude of high-voltage and circuit supply voltages from AC power. A position transducer measures the rotary position of the scanner unit and triggers the transmitter as the scanner unit rotates. The return signal is thresholded to generate a video data signal, portions of which are sequentially stored in separate memory locations, each corresponding to a respective range. The set of video data in memory thus corresponds to targets within a predetermined range in a single direction.

Abstract: A scanning radar system having the capability of taking a number of succeve looks at the same range and angle resolution cells with several millisecond time intervals between looks. The scanning radar system includes a pulsed transmitter, a receiver, and an array of energy beam radiators having individual beam paths with associated centerlines. A commutator switch and a duplexer sequentially connect a different one of the radiators to the pulsed transmitter at the beginning of each pulse repetition period and to the receiver during the subsequent interval between pulsed transmissions. A motor rotates the array of radiators as a unit to cause the beam path centerlines to rotate and scan the field of view.

Abstract: Antenna alignment in troposcatter systems is accomplished by: (1) nutating the antenna receiver beam with a sinusoidal nutation signal to induce envelope modulation on the received signal; (2) crosscorrelating the envelope of the received signal with the nutating signal; and, (3) aligning the average angle of the antenna receiver beam into the position where the crosscorrelation goes to zero.

Abstract: A method and system are described for transmitting electromagnetic radiation by using a communications mirror located between about 100 kilometers and about 200 kilometers above ground. The communications mirror is kept aloft above the atmosphere by the pressure of the electromagnetic radiation which it reflects, and which is beamed at the communications mirror by a suitably constructed transmitting antenna on the ground. The communications mirror will reflect communications, such as radio, radar, or television waves up to about 1,100 kilometers away when the communications mirror is located at a height of about 100 kilometers.

Abstract: An antenna mounting structure is supported and oriented by three linear hydraulic actuators responsive to linear position transducers of a passive stabilization system serving as a vertical reference for keeping an antenna precisely pointed at a geostatically satellite during motion disturbances. The antenna is assembled with each of the linear actuators connected thereto through a gimbaled mount which facilitates accommodation of the requisite angulation thereof necessitated by motion in adjacent actuators. Response in each actuator is derived through an independent linear servo loop directly communicating with a linear position transducer constructed in scaled replication of the respective antenna actuator geometrical configuration and assembled to an inertially stabilized platform.

Abstract: Each of a plurality of antenna sectors is sequentially coupled to a receiver via an antenna switch. The switch is operated by control logic circuitry which monitors the peak signal levels of the signals received by each sector. Unique circuitry is implemented which prevents the control logic from responding to spurious transient signals processed by the receiver's tuned circuits following each instance of antenna switching.

Abstract: There is described an electronic scanning antenna comprising a multiplicity of elementary radiators arranged for example in a vertical plane and constituting an array designed for simultaneous surveillance and tracking, the array being fed by two parallel waveguides. The first waveguide is connected to the radiators through a set of first couplers in cascade with a set of fixed phase shifters. The second waveguide is connected to the radiators through a set of second couplers in cascade with a set of variable phase shifters and with the first couplers and the fixed phase shifters. The waveguides are connected to respective transmitters and receivers operating at different frequencies. The complete assembly produces simultaneously at least one tracking beam which varies in elevation and one searching beam having a fixed, preferably low elevation angle.

Abstract: A first column is secured to and extends vertically upward from a base. The first column has a first socket on the end thereof remote from the base. An intermediate member having first and second balls extending therefrom in opposite directions along a common axis is disposed to have the first ball rotatably engage the first socket. A second column having a second socket on one end thereof is disposed so that the second ball rotatably engages the second socket. An antenna structure is secured to the other end of the second column. A drive arrangement including a plurality of perforated tapes coupled in a predetermined manner to the intermediate member, the base, the first and second columns and the antenna structure provides the complete hemispherical coverage by the antenna structure.