Abstract: An omnidirectional, multiple unit antenna comprises a mounting assembly and a plurality of sector antennas carried on the mounting assembly. Each sector antenna is active to send or receive signals primarily through an angular, horizontal sector having an angle of no more than about 180° around the mounting assembly. The sector antennas carried on the mounting assembly are positioned so that sectors of the respective antennas cover substantially all horizontal directions. Each sector antenna preferably has a separate input, for improved control.

Abstract: An antenna apparatus (200) including a forward link antenna array (212, 214, 216, 218) and a reverse link antenna array (210, 214, 220, 222) coupled by a plurality of circulators (224, 226, 228). The circulators direct the signals for the forward link and reverse link to and from the appropriate antenna elements in the appropriate direction. The forward link and reverse link antenna arrays use a common set of coaxial cables (230) to communicate with the base station circuitry.

Abstract: An antenna array for use with a mobile subscriber unit in a wireless network communications system. The invention utilizes a multiplicity of resonant strips provided within the ground plane. These strips couple to an equal multiplicity of monopole array elements located on top of the ground plane. This approach increases antenna gain by more efficiently utilizing the available ground plane area. Additionally, since the active element is on top of the ground plane, the antenna array sensitivity is decreased because the direct coupling between the antenna and external environmental factors is minimized. The multiplicity of antenna elements are electrically isolated from the ground plane. Each antenna element has a bottom end located proximal to the ground plane, and is aligned along a respective antenna axis that is substantially perpendicular to the top side.

Abstract: An antenna array structure is disclosed for use in receiving, transmitting, or transceiving electromagnetic radiation. The antenna array structure includes a first planar substrate with one or more grooves formed therein with at least one secondary planar substrate having an antenna formed thereon placed in one of the grooves in the first substrate. The use of this three-dimensional structure takes advantage of the inherent directionality due to the guidance of electromagnetic radiation by the secondary planar substrate. This antenna array structure provides the advantages of reduced cross talk between adjacent antennae and can readily be produced using standard silicon fabrication techniques.

Abstract: An antenna system for use in cellular and other wireless communication includes a dual polarized compact antenna array. In one embodiment, the antenna system includes four T-shaped dipole antenna elements mounted on a ground plane, forming a side of a square shaped array. In another embodiment, the antenna system includes seven T-shaped dipole antenna elements mounted on a ground plane to form two side by side square arrays, wherein the square arrays share a common T-shaped dipole antenna element.

Abstract: For broadcast transmission of Differential GPS data signals, a vertical array antenna provides broad band omnidirective phase-progressive radiation with elliptical polarization. Four-dipole sub-arrays use diagonally aligned two-piece cut and bend dipoles with isolated conductive frontal strip. With these vertically arrayed sub-arrays, lower and upper sub-arrays are excited at 70 percent amplitude and respective plus and minus 90 degree phase rotation relative to middle sub-array, for optimized performance with low elevation lobing. Divided transmission line operation provided by the frontal strip of appropriate length achieves double-tuned dipole performance with very low VSWR over the operating band.

Abstract: An antenna system that includes a plurality of mounting plates arranged in a generally circular configuration. Each mounting plate has an inside surface and an outside surface. Each antenna element has a high frequency end and a low frequency end. The low frequency end of each antenna element is mounted to the inside surface of one of the mounting plates such that the high frequency ends of opposed antenna elements face each other. The high frequency ends of opposed antennas are separated by one wavelength of the signal frequency received at the high frequency end. The antenna system also includes a beamforming network having a plurality of input ports equal to the number of antenna elements. Each antenna element is coupled to the beamforming network through a respective input port.

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: An antenna system including a support structure and an antenna assembly having an open grid reflector structure in a closed ring and dipole elements. The antenna assembly includes a number of antenna panels, each including a number of the dipole elements, the closed ring is self-supporting and connected to the support structure by radial beams and struts, and the antenna panels are interconnected by a variable angle connection.

Abstract: Plural antennas are located sufficiently closely to associated radiation reflective surfaces for consequential reduction of elevation beam-width and increase gain in azimuth. Two pairs of antennas associated with differently directed said radiation reflective surfaces afford diversity action. The antennas can be dipoles and the reflective surfaces can be faces of a housing box for related electronics.

Abstract: An omni directional coverage multibeam antenna relief on a ground surface having simple conical shapes to provide beam steering. One advantage of such a system is that the projected area is always constant and broadside to the intended direction resulting in limited scan loss effects. In the case of a cylinder as the conical shape, z-axis symmetry provides a constant antenna aperture projection in any azimuthal direction. Using this geometry, high level, side lobes are reduced considerably because of the natural aperture tapering from dispersion effects. Coverage area and power can be controlled by changing the ground surface angle and by selectively activating different antenna beam positions around the circumference of the ground surface, and by selectively changing the phase relationship between a given set of antenna beams.

Abstract: A dual frequency batwing antenna includes a larger batwing with smaller UHF batwings located in substantially the same plane but within a vacant space provided by the larger batwing. The smaller batwings are also co-linear so there is no inductive coupling. Thus a pair of radio frequency signals are radiated from a common aperture.

Abstract: A communication system for transmitting data between a transmitting platform and a receiving platform moving relative to each other. A phased array antenna forms the transmitting antenna rotated on the transmitting platform and a single dipole, oriented parallel to the transmitting antenna, forms the receive antenna located on the receiving platform. The phased array antenna is split into small sections, each section comprising dipole elements and a matching network, including a feedpoint. The receive antenna is mounted close to the transmitting antenna.

Abstract: The need to widely separate antennas (e.g., transmit and receive antennas) for VHF radio and other applications is avoided by high-isolation antenna systems with collocated antennas and cancellation of intercoupled signals. A transmit antenna in the form of a vertical dipole can be mounted atop a mast with a receive antenna comprising a multi-element array of vertical dipoles supported on the same mast below the transmit antenna. Opposing pairs of the dipole receiving elements are located in 180.degree. positions on opposite sides of the mast so as to be symmetrically located in the omnidirectional antenna pattern of the transmit antenna. Resulting intercoupling to the receive dipoles is equal and in-phase and is cancelled out by the antiphase combining of signals from the dipoles of each pair of the receive dipoles. Reciprocally, cancellation of coupled signals is achieved with reversal of the receive and transmit functions of the respective collocated antennas.

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: A broadband multi-element antenna having desirable phase, standing wave and polarization characteristics is disclosed. The antenna is arranged as a plurality of airfoil shaped elements located in radial planes about a central axis with the element peripheries collectively defining a horn shaped surface--centrally disposed of which is a ground plane member of preferably truncated conical shape which includes electrical feeding arrangements having in phase and out of phase element coupling. The antenna is suitable for radar, satellite, and other precision uses including military applications.

Abstract: An antenna for circularly polarized television transmission comprising, an elongated coaxial waveguide having inner and outer conductors, the outer conductor of the waveguide having a multiplicity of slots spaced along the length and around the circumference of the outer conductor for radiating horizontally polarized energy, a multiplicity of dipoles mounted on the outer surface of the outer conductor and spaced along the length and around the circumference of the outer conductor for radiating vertically polarized energy, each of the dipoles being associated with one of the slots so that the combination of the horizontally and vertically polarized radiation produces circularly polarized radiation, and coupling means for coupling electromagnetic energy from the interior of the waveguide to the slots and the dipoles, the coupling means for both the slots and the dipoles picking up electromagnetic energy from the interior of the waveguide in a common transverse place.

Abstract: An antenna system comprising a vertical monopole antenna coupled to a first feed on a ground plane conductor and a dipole antenna comprising a plurality of horizontal dipole antenna elements coupled to a corresponding plurality of feeds on the ground plane conductor, the plurality of dipole antenna elements being disposed about the first feed. The vertical monopole antenna comprises a plurality of monopole antenna elements, the plurality of monopole antenna elements and the plurality of dipole antenna elements being alternately radially disposed about the first feed.

Abstract: A wideband antenna with reduced diameter and volume compared to prior art tennas and having non-critical dimensions resulting in ease of manufacture and tolerance to damage in portable applications and during installation. In one embodiment the antenna is comprised of a vertical element, a number of equally spaced, equal length horizontal elements in the form of a disc and a number of equally spaced, equal length round plane elements in the form of a cone. The vertical and horizontal elements are connected to the inner conductor of a coaxial transmission line and the conical elements are connected to the outer conductor transmission line. In a second embodiment of the present invention, the vertical element is deleted and a parallel inductor is connected between the transmission line outer and inner conductors.

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 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: An omnidirectional communications antenna for transmitting and receiving horizontally polarized waves and adaptable for transmitting and receiving vertically polarized waves. The antenna is adapted to be supported on a single mast. It may be dimensioned especially for use in the citizens band. The antenna utilizes a plurality of, and preferably three, elongated half wave length radiating elements supported on a mast in a horizontal coplanar array. A cam acting locking mechanism for easily and firmly securing an antenna to a mast, or the like, is also disclosed.