Abstract: An antenna is provided that includes a mast, a first dipole, and a second dipole. The first dipole crosses with the second dipole, and the first dipole and the second dipole form a first antenna assembly that is coupled to the mast. A hybrid power divider is coupled to the first antenna assembly, and an internal feed system, positioned within the mast, is coupled to the hybrid power divider. The antenna may include a rigid coaxial internal and external feed system.

Abstract: An antenna system with at least one tunable dipole element with a length adjustable conductive member disposed therein that enables the antenna to be used over a wide range of frequencies. The element is made of two longitudinally aligned, hollow support arms made of non-conductive material. Disposed longitudinally inside each element is a length adjustable conductive member electrically connected at one end. In the preferred embodiment, each conductive member is stored on a spool that is selectively rotated to precisely extend the conductive member into the support arm. The support arms, which may be fixed or adjustable in length, are affixed at one end to a rigid housing. During use, the conductive members are adjusted in length to tune the element to a desired frequency.

Abstract: Systems and methods for providing antenna beams having reduced grating and side lobes when steered off of the antenna broadside are disclosed. According to the present invention an arrangement of antenna elements suitable for use in generating antenna beams steered at greater angles off of the antenna broadside is utilized with a beam feed network consistent with the antenna beams being steered at the greater angles and reduced antenna element spacing to provide the reduced grating and side lobes. A preferred embodiment utilizes a 2n+1 Butler matrix coupled to 2n+1 antenna columns spaced according to the present invention to provide 2n antenna beams. Preferred embodiments provide a dual mode antenna system in which antenna elements of a first mode are interspersed with antenna elements of a second mode.

Abstract: The invention provides an elongate antenna.

Abstract: An array of antenna elements including a feed board that includes a power divider network and a balun section. According to one aspect of the invention, there is provided a horizontally polarized antenna arrangement including a feed board, a plurality of horizontally polarized antenna elements, and a reflector. The antenna elements are a plurality of dipole pairs. The feed board has two faces. The first face includes a power network and a balun section, that feeds power to the plurality of antenna elements, and the second face includes a ground plane. The fact that the feed board includes a balun section allows the antenna elements to be etched on an inexpensive board or, in the alternative, allows the antenna elements to be individual wires or plates. The antenna arrangement also includes two tuning means, line extensions in the power network and tuning stubs etched to the ground layer, which make it easier to tune the antenna.

Abstract: An omni-directional, planar folded dipole antenna and related quadrature phase shifter implemented on printed circuit boards (PCBs) having differing properties that are perpendicularly engaged. The planar antenna segment is implemented on a single-sided inexpensive PCB and a quadrature phase shifter and system electronics are implemented on more expensive multi-layer PCBs. The invention reduces cost and improves system reliability because coaxial or like connectors of varying material and installation quality are not required between a planar antenna and a quadrature phase shifter. Planar antenna transmits radio frequency signals in an omni-directional pattern and is capable of receiving signals from remote dipole antennas positioned in arbitrary physical orientations. The quadrature phase shifter provides both phase shifting functions and also converts an unbalanced radio frequency transceiver output signal into a balanced input signal to the planar antenna.

Abstract: A two-element driven array with improved tuning and matching. First and second elongate conductive elements are provided having respective feed point gaps disposed substantially at their centers, the second elongate element being substantially coplanar and parallel with the first elongate element and spaced a predetermined distance therefrom. A phasing transmission line is connected between the feed point gap of the first elongate element and the feed point gap of the second elongate element so as to reverse the polarity there between. A variable transmission line having a movable shorting member is connected at one end thereof to the second end of the phasing transmission line. The first end of the phasing transmission line is the feed point for the antenna. A combined balun and impedance matching network is providing for coupling the antenna to an unbalanced, coaxial feed line. The combined network includes a shorting stub to adjust the impedance match between the antenna and the feed line.

Abstract: Indoor UHF antennas for HDTV and ATSC television signals each include a reflector backplate from which is supported one or more dipoles. Both passive and active antennas are disclosed. The active antennas include: single amplifier with a single dipole; push-pull amplifier with a single dipole; two amplifiers with two parallel dipoles; and two push-pull amplifiers with crossed dipoles. The dipole plates comprise printed circuit boards with the amplifiers directly deposited on the obverse sides of the dipole plates.

Abstract: A self-contained four-dipole element provides a 360 degree phase-progressive-omnidirectional (PPO) circularly polarized antenna pattern. Via a single signal port, a PPO excitation network incorporated into the element excites the four dipoles at phases differing by successive 90 degree increments. The four-dipole element is adapted for efficiently reproducible fabrication using printed circuit techniques. Antennas employing a stack of the elements provide a hemispherical antenna pattern with PPO circular polarization and a sharp cutoff below horizontal. For GPS reception in Differential GPS aircraft landing applications, a 21 element antenna provides multipath suppression and a unitary phase center enabling avoidance of signal phase discrepancies. More or fewer elements may be employed in other applications.

Abstract: Systems and methods for providing antenna beams having reduced grating and side lobes when steered off of the antenna broadside are disclosed. According to the present invention an arrangement of antenna elements suitable for use in generating antenna beams steered at greater angles off of the antenna broadside is utilized with a beam feed network consistent with the antenna beams being steered at the greater angles and reduced antenna element spacing to provide the reduced grating and side lobes. A preferred embodiment utilizes a 2n+1 Butler matrix coupled to 2n+1 antenna columns spaced according to the present invention to provide 2n antenna beams.

Abstract: A patch antenna having enhanced frequency response has a generally planar element formed of a substantially conductive material, and antenna feed conductor electrically connected to the antenna element, and a generally planar parasitic element formed of a substantially conductive material positioned substantially coaxially with respect to the antenna element and spaced apart therefrom. The distance by which the parasitic element is spaced apart from the antenna element in order to provide such enhanced frequency response of the patch antenna is determined empirically. An optimally configured array of such patch antennas is also disclosed.

Abstract: A multi-element, H plane, phase, dipole array antenna has a high gain over a wide angle in azimuth and over a controlled sector in elevation. Two printed wiring boards feed and physically support the dipole antenna elements. The phase and spacing of the dipole elements establish the radiation elevation angle, and a planar metallic reflector, spaced on the order of a half wavelength of the RF signal from the dipole array, interacts with the dipole-element pattern, to provide the wide angle azimuth gain.

Abstract: A method and arrangement improve antenna performance parameters. The antenna includes a radiating device for radiating a beam in a substantially predefined direction. The radiating device is provided on a supporting structure. The arrangement includes at least one device to mechanically tilt the radiating device in a first direction substantially diverging from the predefined direction, and a device to tilt the beam in a second substantially opposite direction electrically.

Abstract: Described herein is a variable directional antenna apparatus wherein an electrical length of a parasitic antenna of a paired two-element Yagi antenna is varied to change antenna directivity. A radio device (12) outputs a received signal corresponding to the intensity of an electric field received by a first antenna. A control circuit (15) outputs a control signal to a variable impedance circuit (14) according to the result of detection of the received signal so as to change the impedance of the variable impedance circuit (14) according to the control signal. Thus, an electrical length of a second antenna (13) placed in parallel away from the first antenna (10) is changed to thereby activate the second antenna as a director or reflector, whereby antenna directivity is varied.

Abstract: A planar array antenna having radiating elements characterized by dual simultaneous polarization states and having substantially rotationally symmetric radiation patterns. A distribution network, which is connected to each dual polarized radiator, communicates the electromagnetic signals from and to each radiating element. A ground plane is positioned generally parallel to and spaced apart from the radiating elements by a predetermined distance. The conductive surface of the ground plane operates to image the radiating elements over a wide coverage area, thereby enabling a radiation pattern within an azimuth plane of the antenna to be independent of any quantity of radiating elements. A central polarization control network (PCN), which is connected to the distribution network, can control the polarization states of the received signals distributed via the distribution network by the radiating elements.

Abstract: A hybrid logarithmic yagi antenna system characterized by the absence of a balun or other conventional log periodic yagi antenna system balanced feed and impedance matching element. The reflector element is configured as a supporting conductive tray which provides a rugged mounting mechanism for mounting the antenna system, at its reflector end, to a support structure such as a building.

Abstract: A multifunction antenna system is selectively operative over the UHF and VHF frequency ranges using a novel arrangement of symmetrically disposed phased radiating elements that function as a dipole turnstile type array at UHF and as a monopole at VHF. At VHF the UHF radiating elements and feedlines are fed in parallel against ground to produce a pattern similar to that of a short vertical monopole. VHF and UHF coupling networks offer low VSWR and minimize circuit losses when utilized with a folded dipole array. The compact, lightweight structure is adaptable to oceanic communications by installing in a towed radome adapted for water flotation, and provides low angle hemispherical UHF radiation without pattern switching, with the water surface providing a reflective ground plane.

Abstract: A RF antenna system mounted on, for example, a dielectric carrier plate is accommodated as a homing head in the front under a radome in a missile provided for locating radar systems or the like, in addition to other, further sensors potentially present in free spaces. The RF antenna system is composed of a three's or four's group of logarithmic-periodic crossed dipole antennas whose long axes proceed with optimized dimension obliquely relative to one another and that are interconnected with a monopulse feed network for taking aggregate and difference diagrams in azimuth and elevation. The antenna system for long-range missiles enables a monopulse position fixing in azimuthal or, respectively, elevational direction in an extremely broad frequency range.

Abstract: A multi-element, H plane, phased, dipole array antenna has a high gain over a wide angle in azimuth and over a controlled sector in elevation. Two printed wiring boards feed and physically support the dipole antenna elements. The phase and spacing of the dipole elements establish the radiation elevation angle, and a planar metallic reflector, spaced on the order of a half wavelength of the RF signal from the dipole array, interacts with the dipole-element pattern, to provide the wide angle azimuth gain.

Abstract: An improved antenna system for use at high frequencies such as cellular communication and PCS frequencies, having a steerable, multi co-linear array antenna in which the number of radiating elements per co-linear array increases monotonically from the periphery of the antenna to the middle of the antenna, and wherein the antenna is connected to a Butler matrix feed network, thereby providing steerability of the radiation pattern associated with the antenna. The improved antenna system achieves significantly lower sidelobe generation as compared to antenna systems using multiple co-linear arrays of radiating elements in which the number of radiating elements per co-linear array is constant. The Butler matrix feed network is implemented via a microstrip fabricated printed circuit board without crossovers.

Abstract: The disclosure relates to broadcasting by means of rotary antennas using wire dipoles. Two distinct feeder channels respectively leave two transmitters, go through the joint that separates the fixed support from the mobile part of the rotary antenna, then go out horizontally, on either side of the mast, taking support on the bearing structure of the rotary antenna to then rise vertically to the supply points of the dipoles of two distinct vertical groupings of the dipoles: it is thus possible to carry out two simultaneous transmissions from one and the same rotary antenna. Application to broadcasting in decameter waves.

Abstract: A low noise dual polarization electromagnetic power reception and conversion system is disclosed. It comprises a first plurality of conducting elements performing a bandpass function on incident waves, a second plurality of antenna units, located behind the first elements, performing a power reception and conversion function, and a third plurality of conducting elements located behind the antenna units, performing a bandstop function on incident signals. A layer of lossy material is optionally disposed behind the third elements to absorb any wave passing through them. This system can be used to achieve high efficiency power reception and conversion and also reduce levels of radiation of both harmonics of the powering frequency and intermodulation products formed by nonlinear mixing of signal wavefields from other users of the radio spectrum with the powering signal wavefield.

Abstract: A panel antenna suitable for use in cellular communication applications provided with means for mechanically and electrically adjusting the tilt of the antenna beam. Electrical down tilt being achieved by varying the length of a first feed line to a group of dipole pairs. Mechanical down tilting of the antenna beam being achieved by tilting the antenna ground plane and dipole driver assembly with respect to a housing.

Abstract: A dual polarized dipole array antenna for high efficiency power reception or transmission of electromagnetic waves comprises an array of dipole antenna elements and connecting transmission lines, all highly symmetrically arranged each other on a dielectric layer. Rectifiers and wave filters are added to the transmission lines to produce rectified outputs of each dipole antenna element.

Abstract: A broadband antenna array, formed of pairs of horizontally-spaced dipoles that are balun-fed, uses an air dielectric microstrip binary-feed network to optimize antenna bandwidth. Each dipole is fed by a three-wire balun which maintains the proper current distribution on the dipoles over the operating bandwidth. The binary-feed network feeds each dipole individually to further optimize the antenna's pattern bandwidth. The binary-feed network is formed using a conductive ground plane with spaced conductors to utilize an air dielectric, thereby minimizing antenna losses in the feed network. The feed network impedances are chosen to give a broadband impedance match to the dipoles, and the entire assembly of binary-feed network and dipoles is mounted in a reflector box, the dimensions of which are chosen to control the antenna beamwidth. Vertically stacked pairs are used to compress the vertical radiation pattern for greater antenna gain.

Abstract: A planar array of linearly polarized antenna elements, each element tilted so that its polarization orientation is disposed at an angle with respect to the array vertical axis so that array polarization loss is minimized as a function of roll about an array normal. Half of the elements are tilted uniformly at a positive angle with respect to the array vertical axis and the remaining elements are tilted at a negative angle with respect to the array vertical axis. The invention substantially reduces the unwanted variation in received RF energy magnitude as a function of array roll angle caused by polarization loss, for both vertical and horizontal components. The vertically polarized signal component magnitude remains nearly constant with respect to array roll angle values of 50.degree.-60.degree. and more. If the element tilt angle magnitude is between 0.degree.-45.degree.

Abstract: A radio direction finding antenna system including four identical radiating elements uniformly distributed on a circle around a conductive mast and designed to determine the angle of incidence of the propagation direction of a plane electro-magnetic wave relative to a reference direction, wherein the radiating elements are associated in first and second pairs of opposite radiating elements in which the elements are inverted relative to each other, and wherein the antenna system includes a processor unit comprising firstly a first matched power halver receiving the signals provided by the first pair of radiating elements and a second matched power halver identical to the first and receiving the signals provided by the second pair of radiating elements, and secondly a 3 dB-90.degree. type hybrid junction receiving the signals delivered by the matched power halvers and providing two output signals at a phase difference of 2.theta.-1/2.pi.. The invention is applicable to radio location.

Abstract: The disclosed antenna is designed notably for the emission of television and radio broadcast signals in the decimetrical wavebands. It comprises:a vertical, central supporting tube,a plurality of identical radiating networks evenly distributed around the central tube, each consisting of a vertical bifilary line symmetrically supplying, supporting and coupling a plurality of horizontal dipoles evenly distributed along this bifilary line, and,a system for the distribution of equiphase, equal power, identically and simultaneously supplying the radiating networks through a single coaxial supply line. The antenna has a reflector thus substantially reducing its weight and its windward surface as compared with standard antennas with panels generally used in this band. Advantageously, these antennas are superimposed and enclosed in a sealed radome which is substantially cylindrical and self-supporting and superimposable. This antenna gives an omnidirectional diagram with 0.

Abstract: In a printed circuit embodiment, dielectric boards in a multilayer arrangement have their ends protruding from a ground plane. Sets of printed dipole elements are disposed along the edge of each board. Each set of dipole elements has three feed ports. Bandpass filters are provided for each feed port. Phase shifters are coupled to each of the feed ports through its respective bandpass filter. At the low band, the outer feed ports are shorted by the filters so that the two sections of dipole elements to the left of the center feed port form one lone band dipole arm, and the two sections of dipole elements to the right of the center feed port form the other low band dipole arm. The low band dipole is driven at the center feed port. At the high band, the center feed port becomes an open circuit so that the two sections to the left thereof form one high band dipole, and the two sections to the right thereof form a second high band dipole. The two outer feed ports drive the dipole array at the high band.

Abstract: An antenna formed by an array of dipole elements fed by a triplate or stripline system is provided with earthed posts between the dipoles. These posts prevent radiation from one dipole being received by others thereby improving the antenna efficiency.

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: An antenna array for receiving dual polarized electromagnetic waves, comprised of a first thin-film printed circuit rectenna having a plurality of linear half-wavelength dipole antennae oriented in a first direction for receiving a first component of the dual polarized waves, and a second thin-film printed circuit rectenna parallel to the first rectenna, having a plurality of linear half-wavelength dipole antennae oriented in a second direction for receiving the second orthogonal component of the electromagnetic waves. A reflector screen is disposed parallel and behind the second rectenna, for reflecting incident electromagnetic waves transmitted through the first and second rectennae back to the first and second rectennae for reception thereby.

Abstract: A central aperture provides at least two radiation pattern modes. A second aperture concentric with the central aperture provides at least two radiation pattern modes. A first feed system excites the central aperture and a second feed system excites the concentric aperture. Circuit means associated with the second feed system provides an auxiliary excitation to the concentric aperture which results in optimizing the radiation pattern obtained during excitation of the central aperture.

Abstract: A printed circuit dipole monopulse antenna includes a planar printed circuit substrate having a plurality of dipole antennas and a feed network including a sum and difference hybrid printed thereon. Low sidelobe and monopulse operation are provided along one axis of the antenna.

Abstract: Ultra-broadband impedance matched electrically small self-complementary pair antennas using thin wire elements with impedance inverting feed are presented. Efficiencies are determined by achieveable loss resistances in the radiating structure itself, rather than the (limited) quality of an external loading coil, and by energy channeled into the difference port of the feed hybrid, that is used to match two complementary impedances. Broadband impedance loci are achieved for thin radiators by impedance inverters placed prior to the complementarizing circuit. Impedance matching is then accomplished in a standard broadband hybrid or "Magic Tee" feed circuit.

Abstract: A subsurface antenna system including at least one pair of radiating elements and feed system is buried within a subsurface medium. The radiating elements comprising the system are spaced apart at least one quarter free space wavelength at an operating frequency. The radiating elements are spaced from each other and the feed system provides appropriate relative phase to signals at the elements to produce from the antenna system a directional antenna pattern in free space.

Abstract: A bistatic VHF Doppler radar is utilized to detect and track one or more intruders crossing a large annular ring surveilance zone surrounding a central high security installation. A central omni-directional transmitter radiates the surveillance zone with a continuous wave (CW) signal. Predetermined ones of a plurality of receiver antennas circumferentially spaced around the surveillance zone receive a portion of the signal which is reflected by an intruder crossing the surveillance zone and a portion of the signal which is directly radiated from the transmitter antenna. The reflected signal portion may be received by antenna arrays each of which is controlled to form a null in its pattern toward the transmitter antenna to overcome direct signal overload. The direct signal portion may be received by stub antennas. Each antenna array and each stub antenna is connected to a separate channel of a dual channel receiver.

Abstract: An FM antenna for use with a radio receiver which features plural, elongate open loop reception elements which are mutually coupled to one another. These elements may be equidistantly arranged about and spaced from an axis generally parallel with the element sides. The antenna is particularly effective for receiving weak and/or distant FM signals.

Abstract: A multiple ring dipole array comprises a plurality of dipole elements arranged in concentric rings and in a common plane. Each ring has a plurality of circumferentially spaced dipole elements, preferably folded dipoles, having equal lengths and disposed in opposed parallel pairs with elements of each pair spaced by one-half wavelength at center frequency. The elements of adjacent arrays have different lengths selected to provide contiguous or slightly overlapping operating frequency bands, the elements of one ring extending in directions transversely of the elements in the adjacent ring to minimize mutual coupling. Each element is fed by a pair of phase-matched coaxial lines connected to suitable switching circuitry by a hybrid junction. The array has a common phase center over the entire band and so has particular utility as a feed for a parabolic reflector.

Abstract: A lightweight, efficient, microwave power transmitting antenna is disclosed, suitable for use in a space borne transmitter for beaming solar generated electrical power down to earth based receiving antennas. The space borne antenna structure is formed by modules that are structurally integrated into a multimodule antenna array. Each module comprises a rectangular framework of limited depth having rigid sides circumscribing a generally open region in which a plurality of spaced parallel single wire Goubau transmission lines are strung to create a "see-through" harp-like configuration. A Klystron powered feed wave guide is disposed as one structural side of the module for exciting standing electromagnetic waves on the plurality of Goubau lines. Printed circuit Yagi endfire radiators are supported on dielectric webs disposed in juxtaposition with the Goubau lines for being synchronously excited by the standing waves on such lines.

Abstract: A highly compact and lightweight 82 channel all band VHF-UHF television antenna having three antenna elements wherein each element is the identical physical length and each element includes two half sections. Each antenna element is separated a predetermined distance from each other element wherein the predetermined distance is substantially less than one-tenth of the shortest wave length in the VHF band. A first set of coils are utilized to electrically lengthen the halves of the two elements for reception in the VHF band and a second set of coils are utilized to provide proper delays between the signals received by each antenna element so that when the signals are combined the signals are substantially additive and in phase. The antenna system includes a weatherproof housing containing a rotor, a preamplifier, and electronic circuitry.

Abstract: An antenna array radiation pattern switching system suitable for use in re-gated, pulse doppler, radar systems. The antenna array includes first and second antennas, one of which is fed through a fixed phase-shift network while the other is fed through a phase-shift network with double the phase shift of the fixed phase-shift network that can selectively be switched in and out of the feed circuit.

Abstract: An improved antenna system is disclosed in which a single antenna array is simultaneously used in conjunction with several independent radio devices. Isolated and independent radio transmitters are coupled, without any signal cancellation, to each and every one of a plurality of isolated independent antenna elements by a combining network which maintains the isolation between each of the radio transmitters and each of the antenna elements. The combining network comprises an array of hybrid networks and creates a predetermined electrical phase difference between each signal received by an individual antenna element. The antenna elements form a single antenna array consisting of circularly disposed corner reflector antennas. Each reflector independently creates an individual radiation pattern and these patterns combine to form a single desired composite radiation pattern.

Abstract: The linear antenna array comprises three or more element antennae which are disposed along a straight line and a feed circuit network connected to the element antennae via an inversion circuit for inverting power in opposite phases. The feed circuit network comprises a plurality of power dividers having common ports connected to respective element antennae, and split ports of a number corresponding to a binomial coefficient, phase shifters respectively connected to the split ports, and a common power divider connected to the phase shifters.

Abstract: A flexible strap-like antenna which may be supported on the outside surface of an aerostat includes a first substrate member having conductors thereon in a pattern which includes a center conductor and dipole antennas on either side of the center conductor. A ground conductor is disposed over the center conductor and is electrically insulated from it by an insulating strip sandwiched between them. A second or covering substrate seals the layered arrangement.To achieve broad band operation, an array of antennas is provided with the width of the center conductor being varied for certain different sections thereof.

Abstract: An antennae feed or take-off for a plurality of antennae where the transmission line, connecting the antennae to the termination of the line, is in a closed loop whereby signal flows either direction and transmission line phase shifts are largely compensated.

Abstract: An endfire-type phased array antenna comprises n antenna elements (n.gtoreq.3). The difference of current flowing through the antenna elements is controlled to one which is pre-determined by adjusting each length of the feeders and by coupling the phase inverting circuits to alternate antenna elements. The current amplitude ratio thereof is also controlled to a pre-determined value by using a mixing or distributing circuit. Thus an antenna having a high directivity in front and no radiation in other directions is provided which can be effectively used for preventing multi-path interference in TV or FM.

Abstract: The frequency scanned corner reflector antenna is a modified corner refler antenna that incorporates a feeding technique to achieve monopulse or sequential lobing radiation patterns in one principal plane and one or more frequency-scanned beams in the other principal plane. Scanning of the beam of the corner reflector antenna for direction finding and tracking applications is accomplished without destroying the unique monopulse and sequential lobing capabilities of the antenna.

Abstract: Two dimensional beam steering of an antenna array is effected by feeding a lurality of radiating elements from a hybrid matrix that is a beam forming and phasing network in combination with single pole multiple throw switches where switching the various matrix terminals give the elevation beams. Ferrite phase shifters feeding into the single pole multiple switching means provides steering of the antenna beam in the azimuth plane.

Abstract: A low cost broadband antenna system particularly suitable for television reception is described wherein the feed line includes a pair of conductors mounted in insulated manner one above the other above a support boom with the conductors having a fixed separation from each other and from the boom, a fixed conductor diameter and boom dimension maintaining a constant impedance along the line. Dipoles extend transverse the longitudinal axis of the boom and are symmetrically disposed about the axis with the dipole half elements on the same side of the axis successively connected alternately to the first and second conductors of the pair.