Abstract: A polarization feed is provided for use in a directional antenna under separation of two linearly polarized electromagnetic waves whereby the feed is basically comprised of a tube, one end of which flares into a feed horn configuration and two wave guides are connected thereto, one ending laterally with its axial end at the feed tube while the other one has one side connected to the other axial end of the feed tube under consideration that respective long cross sectional dimensions are 90.degree. rotated with respect to each other as connected to the tube. Appropriate means are provided for obtaining low reflection feeding.

Abstract: There is disclosed herein a multi-turn antenna which comprises an electrically conducting surface. This surface consists of an even plurality of symmetric pairs of hollow, substantially isosceles triangular loops. Each pair of loops is electrically connected to its adjacent pair. Each pair comprises an electromagnetic wave guide. Each symmetric pair is disposed parallel to its adjacent loop pair. All loop pairs are disposed perpendicularly to the direction of wave propagation, as defined by a primary broadcast source.

Abstract: A whip antenna system for surface vehicles or the like. The antenna system's tuner has an LC tank circuit, into whose inductor is inserted a coil that is connected to the vehicle's transmitter/receiver, the coil being field coupled to the tank circuit's inductor. The inserted coil provides sufficient reactance that the vehicle need not serve as a counterpoise, thus providing an antenna of comparable size but electrically less close to the ground (i.e. one that has better "seeing"), and useable with non-metallic vehicles (e.g. fiberglass boats).

Abstract: A resonant tag circuit is provided which is useful in conjunction with an electronic security system for preventing theft of articles from a protected area. The tag circuit comprises an electrically insulating substrate having a spiral conductive path on each surface of the substrate. The spiral conductive paths are positioned to overlap each other to effect distributed capacitance. The degree of overlap of the distributed capacitance portion of the conductive paths is such that it provides at least 70%, preferably 90% and most preferably 100% of the total overlapping portions of the circuit.

Abstract: A slotted-cylinder antenna especially adapted for television broadcasting use radiates a circularly-polarized pattern. Each radiating slot is associated with an elongated conductive parasitic radiator in close proximity to the slot for good power coupling therebetween. The parasitic radiator is almost but not quite parallel with the slot (preferably being at a six degree orientation with the slot), so that energy is coupled into the parasite and reradiated almost vertically polarized. The combination of the radiated field of the slot and reradiated field of the parasite is made circularly polarized by selection of that length of the parasite which gives the correct phase-shift.

Abstract: An electrically heated window, for example, a motor vehicle heated rear window, is provided with a signal separating device to enable the heating element of the window to be used simultaneously as a transmitting aerial and for heating purposes.

Abstract: A biax gimballing arrangement permitting both axes of rotation to intersect at a point within a load being gimbaled, thereby permitting the rotational inertia of the load and the gimbal mechanism itself to be minimized. Gimbal rotation about a first axis is achieved by a first drive motor. Rotation in a second axis orthogonal to the first axis is achieved by a steel cable drive assembly having two drive cable ends that are passed through the first rotational axis on their way to respective anchor points within a portion of the gimbal apparatus that is rotated about the first axis. This rotatable portion of the gimbal apparatus includes milled guideways which permit rotation of the gimbal load mount. The central portion of the cable is driven by engagement with a pulley attached to the shaft of a second drive motor.

Abstract: A modular integrated multi-element phased array antenna. The antenna is comprised of a supporting structure having a plurality of slotted, ridged waveguide radiator elements longitudinally extending therein and a single series ridged waveguide feed structure, having a first and second plurality of waveguide channels formed therein. The feed structure is supported by at least a portion of the supporting structure and receives microwave energy from a source and then couples the energy to the first plurality of waveguide channels. The antenna is further comprised of a multi-element phase shifter module positioned in juxtaposition with the feed structure for receiving the microwave energy from each of the first plurality of waveguide channels. The phase shifted energy is coupled from the phase shifter module to each of the second plurality of waveguide channels.

Abstract: A two reflector microwave antenna has a concave focusing main dish having an integral peripheral flange. An integral radome shell also having a peripheral flange is disposed in confronting relationship to the main dish flange. Mounted over both flanges is a clamping ring to keep the main dish and radome shell in a stress condition of fixed edge shells. A secondary reflector is provided on a central portion of the radome. The concave focusing main dish in one example, defines a paraboloid of revolution. Specific shapes of the main dish and the radome shell are selected to appropriately focus the microwave radiation. A radome portion of a variable thickness of dielectric material of the integral radome shell modify the path of microwave energy compensating for diffraction of induced edge spillover. The stress condition of the shells as maintained by the clamp about the flanges provides a structually rigid antenna substantially void of structural elements.

Abstract: A coded linear array antenna comprised of a plurality of multiple element barrays, each providing sin mx/sin x patterns which are combined, i.e. summed into a composite pattern by having the subarrays commonly connected to a signal summation means. Each subarray is comprised of multiple elements which are respectively spaced equidistantly apart and positioned symmetrically on either side of a common array axis center or axis of symmetry and wherein the individual antenna elements of each subarray are positioned at an i.sub.th location according to the normalized equation ##EQU1## where i=1, 2, 3, . . . h, n.sub.m defines the maximum number of elements in the length or aperture of the composite array, h is the number of elements in the respective subarray, and n is proportional to the element spacing of the respective subarray.

Abstract: An optimized feedhorn comprising a circular waveguide having a corrugated plate disposed around the outside of the aperture of the waveguide wherein the corrugations of the plate are capacitive as to E plane signals. The feedhorn includes a reduced aperture diameter which selectively protrudes beyond the plane of the corrugated plate. The amount of protrusion of the aperture is determined to approximately equalize E and H plane beamwidths and selectively shape the top and skirts of the signal pattern around the center frequency of interest.

Abstract: An antenna dish structure is disclosed having a central support to which are attached a plurality of elongated ribs extending radially outwardly with a plurality of metallic mesh members extending between adjacent pairs of rib, and a rim structure connected to the outer ends of the ribs, with both the ribs and the rim having portions for receiving therewithin such mesh members.

Abstract: A space fed microwave lens antenna for deployment in outer space or other remote, hazardous or unattended location. Electronic means are provided for compensating for errors in the mechanical displacement of the phased array feed elements from the phased array lens elements.

Abstract: The miniaturized mobile radio receiver has a straight dipole antenna whose wires run along the edge of the printed-circuit board(s) of the radio receiver and are connected at their outer ends to conductive areas. The conductive strips on the circuit board(s) which run parallel to the antenna constitute a resistive-capacitive shunt and are, therefore, open in the vicinity of the antenna base to block the flow of RF signals.

Abstract: A generally rectangular waveguide antenna has two narrow side walls connected to two broad walls. One of the broad walls takes the form of a conventional rectangular ridged wall. The other broad wall is curved with the arc of the curve extending substantially the full width of the wall. The antenna has an open end and a closed end. The end of the curved broad wall extends beyond the end of the rectangular ridge wall at the open end of the antenna. The two narrow sidewalls are cut at an angle, at the open end, to join the shorter ridged wall and the extended curved wall.

Abstract: A first antenna for radiating a signal at a predetermined frequency employing at least one 1/4 wavelength microstrip resonator positioned below a metal 1/4 wavelength radiator. A circularly polarized antenna including a 1/2 wavelength radiator electromagnetically coupled to a 1/4 wavelength resonator is further disclosed.

Abstract: A compact frequency reuse communications antenna includes two superimposed structures, each including Kevlar honeycomb, fabric face skins on the honeycomb, and a reflector over one of the face skins, the two structures being spaced from one another by Kevlar ribs formed of honeycomb material. The directions in which the ribbons of the honeycomb cores of the superimposed structures extend, and the directions of the elements making up the reflector of the fabric warps are chosen to minimize thermal distortions and RF losses while providing high natural frequency and low weight.

Abstract: A vertical dipole array (2, 3 to 2.sup.(n), 3.sup.(n)) is formed on a substrate (1) using stripline techniques. The dipoles are supplied with RF energy from a feed system consisting of stripline conductors (4, 4', 5, 6, 7, 7', 9, 12). By a parasitic compensating radiator (11) provided opposite these conductors on the same side of the substrate, the influence of the conductors on the radiation pattern of the dipoles is largely compensated for.The conductors of the feed system are arranged so that a combination of a parallel feed and an equal line length series feed (or, if the radiation pattern is to be raised, a series feed with suitably chosen line lengths) is obtained.

Abstract: A beam scanning antenna system that uses a small, rapidly rotatable feed enna to illuminate a large, fixed secondary collimating device, such as a reflector or electromagnetic lens, which in turn illuminates a large, fixed primary collimating device. The primary collimating device forms a narrow collimating beam that is reflected or transmitted into space. Rotation of the small feed antenna causes the beam to scan.

Abstract: A passive duplexer for electromagnetic waves operated within the millimetric wave range. The duplexer comprises a first horn associated with a radar transmitter and having a propagation axis (.DELTA..sub.1), a plane circular grid inclined at 45.degree. with respect to (.DELTA..sub.1), and a second horn associated with the radar receiver and having an axis (.DELTA..sub.2) at right angles to (.DELTA..sub.1). The grid is formed by a network of resonant slots equipped with at least one diode.