Abstract: A communications spacecraft reflector is accurately positioned with respect to its feed assembly by a thermally stable stiff mounting platform which is secured in distortion isolation from the rest of the spacecraft. A yaw actuator can move the platform about an axis parallel to the spacecraft yaw axis.

Abstract: A coil assembly that is essentially isotropic in a plane normal to the plane of the coil includes two flat coils stacked one next to the other. One coil is connected in series with a resistor in a closed loop and has a strip of high permeability material woven through it. The other coil is tuned by a parallel capacitor across its coil terminals, such terminals being connected to electronic circuity. The coil is separated from the printed circuit board that contains the electronic circuitry by a sheet of high permeability material. The assembly is self-contained and powered by a flat battery on which the circuit board is placed. Another embodiment is disclosed that contains only one coil, the terminals of which are connected to a suitable electronic circuit, not shown. Strips of high permeability material are disposed on both sides of the coil and an assembly is produced with a printed circuit board and a flat battery.

Abstract: This invention relates to an antenna material and more particularly to an antenna material comprising, in its preferred embodiment, a woven mesh of amorphous silica fibers, a conductive metal coating on at least the outer surfaces of the mesh and a lubricant covering and adhering to non-metallized surfaces of the silica fibers.

Abstract: A microstrip annular antenna structure is formed by four quarter-wavelength microstrip radiator patches arranged in a quadrant formation and having outwardly directed adjacent radiating apertures which together provide a composite annular radiating slot extending about 360.degree. of azimuth. All such radiators are fed in-phase by a single centrally located feedpoint and equal length microstrip transmission lines extending diagonally therefrom to a respective matched impedance feedpoint associated with each radiator patch structure. An extremely low profile rf antenna system results with a monopole or annular slot vertically polarized radiation pattern.

Abstract: Loop radiating elements for microwave frequencies which result in balanced ower division at the feed points and equi-phase currents in the radiating segments are in the form of an Alford loop design having a "kink" in the stripline path on the side of a printed circuit board opposite the cross-over to restore equal path lengths on both sides of a central feed terminal. Alternatively, the radiating segments of a loop may be in the form of end-loaded bent dipoles which are dual-fed on diametrically opposite points of the loop with equi-phase and amplitude signal. The result is loop radiating elements which have an axial null with a symmetrical doughnut radiating pattern.

Abstract: This disclosure sets forth a device which produces uniform electromagnetic ields in the medium frequency (MF) and high frequency (HF) regimes over significantly large test volumes. The device converts electromagnetic energy available from a standard radio-frequency transmitter into a vertically polarized uniform electromagnetic field which propagates through a large open region and is dissipated/radiated at the termination. A broadband (MF and HF) electromagnetic radiation over a large test volume is provided.

Abstract: An antenna system for an article of furniture in which a panel of the article of furniture is sealed by a low loss dielectric material to isolate the panel from impurities which affect its electrical integrity. An antenna structure is applied thereon by silk screening, painting or otherwise marking of a conductive ink, or by vacuum deposition techniques, or by application of stamped or die cut foil, or by metallic tape, all by way of example. Connections to the antenna structure are made by compressing a conductive elastomeric material against terminations of the antenna structure so as to avoid temperature or other initiated dimensional changes of the panel which could effect the contact resistance to the terminations of the antenna structure, and also to avoid damaging the antenna structure. A specific connection arrangement is disclosed.

Abstract: An antenna is provided equipped with a device which rotates the direction of the rectilinear polarization of a wave transmitted to a receiver (or transmitted by a transmitter) associated with the antenna, with respect to this same wave such as it is received by the antenna (or transmitted by the antenna). The device is formed from a square cross-section wavequide which is twisted in steps and which steps may be adjustable and which is twist guide inserted in the primary source of the antenna, between the horn of the antenna and the receiving (or transmitting) means associated with the antenna.

Abstract: A multifrequency antenna includes a main reflector for signals in a low frequency band. One or more portions of the main reflector are deformed to provide one or more auxiliary reflectors for signals in one or more higher frequency bands. The feed for the low frequency band is located axially of the main reflector, while the feeds for the higher frequency bands are offset to the side of the low frequency feed. The lateral and axial offsets of the vertex of an auxiliary high frequency reflector from the vertex of the main low frequency reflector and the focal length of the auxiliary high frequency reflector are selected to minimize the degradation of the performance in the low frequency band.

Abstract: A dipole antenna and a feedline therefor both formed from coaxial line. The dipole coaxial line has the jacket removed from a central portion thereof to expose the outer conductor which is there severed and spread apart to form a gap exposing the dielectric layer, the lengths of coaxial line on each side of the gap comprising dipole elements. The feedline has the jacket removed from one end portion thereof with its inner conductor being connected to the outer shield conductor of one dipole element on one side of the gap and the outer conductor thereof being connected to the outer shield conductor of the other dipole element on the other side of the gap thereby to form center feedpoint connections between the feedline conductors and the dipole elements. Clamping means comprising a pair of relatively thin flat clamping members of substantially rigid insulating material are provided to be fastened together face to face with the feedpoint connections and adjacent coaxial line portions therebetween.

Abstract: For radio communication with submarine vessels frequency ranges with very low frequencies are used. Even at these frequencies the penetration depth in salt water is only approximately 10 to 20 meters. In order to improve the signal noise ratio or to extend the submerging depth use is made of buoy antennas connected to the submarine vessel by a cable. In order to improve the manoeuvrability of the submarine vessel and to avoid the use of an active control system in the antenna, the antenna is constructed as a torpedo-like hollow body, which at the trailing part is equipped with two hydrofoils resembling a horizontal tail unit, which hydrofoils interconnect the top and bottom of the body to each other as an open arc. Both in the floating body and in the hydrofoils a loop of a crossed-loop antenna is incorporated, which loops are tuned in order to increase the sensitivity. Signal transmission to the submarine vessel is effected via an optical fibre guide, which also transmits the traction force.

Abstract: A collapsible antenna mount includes relatively movable arms pivotally connected to a support means such that the arms can be moved between collapsed positions adjacent each other and deployed positions in which the distal portions of the arms are spaced-apart. In the collapsed configuration, the antenna mount occupies a minimum amount of space for storage. In the deployed position, magnets located in the distal arm portions and the support means provide rigid support for the antenna mount on a car roof or the like.

Abstract: An antenna arrangement for personal radio transceivers in which a main antenna extends from the housing of the transceiver which is excited by a high frequency connector thereof, includes an auxiliary antenna which is coupled to a cold terminal of the connector to form a counterweight for the main antenna. Both the main and auxiliary antennas are resonant and shorter than the quarterwavelength, whereby the housing is placed at a potential minimum and the effects of the close presence of a human body on radiational properties for the arrangement will be reduced.

Abstract: A motor operated antenna for an automobile. The antenna includes a number of telescoping collapsible sections which form a removable unit. A reversible electric motor is mounted next to a fixed antenna tube in which the unit is positioned. The motor raises and lowers the sections in response to a switch actuated by a user. In the event any of the sections comprising the unit are bent or broken a collar holding the unit in place in the tube is loosened and removed. The unit can be withdrawn from the tube and replaced with a new unit.

Abstract: An antenna is provided which includes a first closely wound coil spring member of electrically conductive material. A second closely wound coil spring member which is substantially smaller than the first spring member is wound around a portion of the first spring member adjacent one end thereof. The second spring member is anchored to the first spring member by solder which is flowed into the coils of the first and second spring members where they contact each other. The end of the flexible first element to which the second member is attached is situated within a housing of rigid materials having first and second ends which include upper and lower apertures, respectively, the second spring member is fixedly held between the first and second ends of the housing.

Abstract: A broadband multi-element antenna is presented. The antenna comprises a monopole centrally disposed within a cavity of the body, and a plurality of antenna elements disposed at ninety degree increments about the periphery of the cavity. A plurality of isolation traps are connected between selected pairs of the antenna elements. The isolation traps are half-wavelength transmission lines which permit excitation of the respective plurality of elements by input signals which are of equal amplitude and 180.degree. out-of-phase but are short circuits between the respective pairs for in phase signals parasitically induced from the monopole. Additionally, switching traps are connected to respective ones of the antenna elements. The switching traps comprise quarter-wave transmission lines which are switchable to ground and selectively provide a short circuit of signals at the respective ones of the elements for changing the radiation pattern of the antenna.

Abstract: Certain present antenna assemblies require that their antenna structure be first rotated to a predetermined azimuth orientation prior to being retracted translationally along an axis to a stowed state so that it may conform to the surface of the antenna supporting structure which it is designed to rest against. An antenna assembly which requires no such prior maneuvering of the antenna structure before retraction thereof is disclosed. Retraction of the antenna structure in accordance with the present invention may occur at any random azimuth orientation of the antenna structure. In one embodiment, at least one cam follower bearing is fixedly coupled to a support housing of the antenna assembly and positioned to engage one of a plurality of integral cam grooves disposed on the surface of a shaft which supports the antenna structure and used to extend and retract the antenna structure with respect to the support housing surface.

Abstract: The invention relates to a device for transmitting microwaves between two bodies which are rotatable relative to each other. Two annular waveguides are arranged on a common axis. Each waveguide has a coupling slot along its circumference. A transmitting aerial projects into each coupling slot and is moveable relative to the associated waveguide. The electromagnetic waves generated by the transmitting aerials are received by receiving aerials at the ends of the waveguides, respectively. The outputs of the receiving aerials are prepared for further processing.

Abstract: An improved diversity communication system which has a single micro-strip antenna has been found. The micro-strip antenna according to the invention comprises a thin dielectric layer sandwiched by a ground conductor plane and a radiation conductor plane, a pair of feed points on the radiation conductor plane through the holes on the ground conductor plane, and said feed points being positioned so that a line between a first feed point and a center of the radiation conductor plane is substantially perpendicular to a line between a second feed point and a center of the radiation conductor plane. Each of the feed points is coupled with each branch input of a diversity receiver, and those feed points operate like separated two antennas, which have a pair of perpendicular directivities. Preferably, a radiation conductor plane is circular with a plurality of slots along the periphery of the same. The feed points of the present micro-strip antenna have little correlation between the same.

Abstract: A microwave directional antenna, particularly for the millimeter-wave range, comprises a dielectric line with line discontinuities, affixed to a metallic ground plane. The dielectric line is a radial waveguide extending about a center where the feed is provided. A mode launcher is located at this center. In a preferred embodiment, the boundary of the dielectric line circumscribes a circle; the line discontinuities are preferably embodied as metallic strips arranged on the dielectric guide on circles about the center.