Abstract: An antenna assembly is provided for mounting on a predetermined support structure positioned on a surface, the support structure having a peripheral edge at an elevated position above the surface. The antenna assembly includes an antenna and a support for supporting the antenna at an elevated position above the surface when mounted on the support structure. The support is adapted to support the antenna at a sufficient height above the surface to provide a direct path for electromagnetic radiation at least a portion of the antenna to a position on the surface external of the peripheral edge of less than or equal to about 4.5 meters from substantially any point on the peripheral edge, or to a position on the surface at a point positioned 3 meters from the front of the support structure and 3 meters from a side of the support structure.

Abstract: An omni-directional antenna supporting simultaneous transmission/reception, from the same AP, on multiple frequencies, allowing each AP to communicate using each possible frequency. Each AP multiplexes its outgoing signals onto its transmitting antenna, and de-multiplexes its incoming signals from its receiving antenna. The transmitting and receiving antennae are each substantially located in each other's NULL zone (or one is in the NULL zone of the other). The AP can transmit/receive on many distinct frequencies without needing more antennae.

Abstract: An antenna assembly is provided for mounting on a predetermined support structure positioned on a surface, the support structure having a peripheral edge at an elevated position above the surface. The antenna assembly includes an antenna and a support for supporting the antenna at an elevated position above the surface when mounted on the support structure. The support is adapted to support the antenna at a sufficient height above the surface to provide a direct path for electromagnetic radiation from at least a portion of the antenna to a position on the surface external of the peripheral edge of less than or equal to about 4.5 meters from substantially any point on the peripheral edge, or to a position on the surface at a point positioned 3 meters from the front of the support structure and 3 meters from a side of the support structure.

Abstract: A steerable dipole array including a plurality of end loaded electrically short dipole antenna sections arranged along a common longitudinal axis. The antenna sections include active transmit/receive modules with a common DC power line used to power the modules being used as part of the radiating system while for maintaining DC continuity in the DC power line. The DC power line includes a pair of capacitively coupled electrical conductors extending in an axial direction adjacent the antenna sections and having RF chokes formed therein located adjacent the outer end portions of the antenna sections for reducing the mutual coupling between the electrical conductors and dipole antenna sections.

Abstract: An elevation angle detection device uses signals from first and second of oppositely pointing antennas to determine an elevation angle of an emitting source. The signal from the second antenna is inverted and phase-compared with the direct signal from the first antenna. The first and second antennas are physically displaced along their axes by about ⅜ electrical wavelengths to establish a sensitive angular region of about ±7 degrees. In one embodiment of the invention, the phase of the signal from the first antenna is phase delayed slightly before being applied to the phase detector. This displaces the sensitive angular region upward. The phase of the signal from the second antenna is phase delayed slightly before being applied to a second phase detector. The signal from the first antenna is applied to the second phase detector without being phase delayed. This displaces the sensitive angular region downward.

Abstract: An antenna assembly includes a receiving antenna and a separate transmitting antenna with an isolation circuit disposed in between to thereby isolate the Tx and Rx signals and provide a sufficient amount of attenuation outside the desired frequency band. The dual antenna structure enables the elimination of a conventional duplexer for duplex operation. In this context, the arrangement minimizes occupied space on the PCB while reducing manufacturing costs.

Abstract: A switched gain antenna array comprising a plurality of dipole elements disposed in series with a phasing stub coupled between adjacent ones of the dipole elements. An antenna feed line is coupled to a first one of the dipole elements to couple the RF signals into and out of the plurality of dipole elements. The phasing stubs are adapted to adjust phase of the RF signals provided to each of the dipole elements so that the dipole elements operate in phase. A switch is disposed between the first one of the dipole elements and a second one of the dipole elements. The switch is adapted to disconnect the first one of the dipole elements from remaining ones of the dipole elements during transmit operations of the antenna array and to connect each of the dipole elements together during receive operations of the antenna array. As a result, the antenna array has greater gain during receive operations than during transmit operations.

Abstract: An antenna comprising a first conductive element having a first end and a second end. The antenna is also comprised of a second conductive element having a first end and a second end. The second conductive element is adjacent and essentially in parallel to the first conductive element. The antenna is also comprised of a third conductive element connected to the first conductive element and second conductive element at their first ends therewith so signals in the third conductive element can pass to the first conductive element and second conductive element.

Abstract: A two-wave antenna for telephones used in vehicles which includes two radiating elements in which one end of each of the two radiating elements is respectively connected to one end of a single phase coil and the effective radiating lengths of the two radiating elements are respectively 1/2 .lambda..sub.1 to 5/8 .lambda..sub.1 and an electrical length of the phase coil is 3/2 .lambda..sub.1 to 5/4 .lambda..sub.1 so that currents of the same phase and two frequency bands are carried in the two radiating elements and wherein .lambda..sub.1 is the wavelength of the first band.

Abstract: An arrow incorporating a radio signal transmitting device allows a hunter to find a lost arrow. The arrow includes a hollow aluminum shaft which acts as the primary transmitting antenna. A braded metal cable inside the hollow shaft acts as a secondary antenna when the primary antenna is broken, for whatever reason.

Abstract: The antenna represents colinearly arranged half-wave dipoles. On the side of each final half-wave dipole is a quarter-wave dipole. The connection between the dipoles is alternately capacitive and inductive each providing a phase shift within the range of from 60 to 120 electrical degrees. The terminal of the antenna is asymmetrically deduced from the free end of one of the final half-wave dipoles and the adjacent end of the nearby quarter-wave dipole. This antenna can be used in reception and transmission of electromagnetic energy and shows a considerably increased gain.

Abstract: A high gain vertically polarized antenna section includes a hollow conductive central cylinder which is used to encase feed lines and power dividers used for feeding the antenna section. The cylinder is surrounded by an array of symmetrically disposed vertical radiating elements arranged in a plurality of symmetrical columns. A plurality of ring transmission lines or shorted quarter-wave stubs are utilized to distribute electrical energy to each of the vertical radiators in a manner such that the instantenous current flow is in the same direction in all of the vertical radiating elements. Any horizontal currents in the ring transmission lines or shorted quarter-wave is substantially cancelled by out-of-phase horizontal currents.

Abstract: A collinear series-fed antenna array formed from two spaced-apart electrical conductors extending parallel to one another in a longitudinal direction and having regularly spaced complementary changes in transverse dimensions along the longitudinal direction. These two shaped conductors are connected at one end to an RF transmitter or receiver and are substantially isolated from electromagnetic interaction with other unconnected electrical conductors in the immediate vicinity. The array is preferably fabricated by etching a copper laminate adhered to one side of a dielectric sheet which serves solely to support the shaped conductors etched thereon. There is no ground plane associated with these conductors and the dielectric merely serves to support the antenna elements. The whole assembly can therefore be made very thin and flexible and formed into a compact unit for storage when not in use.

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.