Abstract: A dual-port corporate-feed broadband antenna uses two pairs of crossed dipoles in each bay, fed by a single hybrid coupler in each bay, to support hybrid-mode IBOC® VHF-band broadcasting. Each 3 dB quarter-wave coupler receives a share of an analog FM broadcast signal on a first input and a digital OFDM broadcast signal, 20 dB down, on a second input. The respective coupler output ports drive coaxial lines to tees feeding respective quarter-wave-separated crossed dipoles. The dipoles in each bay are arranged in a square to one side of their coupler, making side mounting practical. The resultant omnidirectional analog and digital radiation patterns have the same circular polarization and opposite phase rotation. Bay spacing for vertical null is a function ((n?1)/n) of the number of bays in the antenna.

Abstract: A vertically polarized traveling wave antenna forms peanut-type directional lobes without significant nulls between the lobes. A self-supporting coaxial line feeds quad-dipole bays coupled around the coaxial line, with opposed dipole pairs spaced along the coaxial line. Matched-layer spacing provides substantial cancellation of the reactive components of the loads. Dipoles are oriented parallel to the coaxial line axis, with opposite “hot” (center coupled) elements oppositely oriented. Radiated signals have rotating phase. Changing the spacing within quads from a quarter wavelength or rotating the second dipole pair of each quad away from a right angle causes the antenna to radiate strongly on one axis and weakly at right angles thereto, without the nulls of back-to-back panel antennas.

Abstract: An antenna system is disclosed that includes a mast, waveguides positioned about the mast, and a feed system positioned external to the mast and between adjacent waveguides, such the feed system can be easily serviced. The waveguides include radiator elements that are easy to manufacture, and thus reduce the cost associated with wideband cavity-backed antennas. Further, adjustable disc-like and spherical radiating elements for exciting the fields in the waveguides are also disclosed. DC voltage buildup on the radiating elements are grounded by an easily attachable coaxial structure.

Abstract: A circularly polarized, omnidirectional, corporate-feed pylon antenna uses multiple helically-oriented dipoles in each bay, and includes a vertical and diagonal support arrangement of simple structural shapes configured to provide a frame strong enough to sustain mechanical top loads applied externally. The radiators in each bay fit within the vertical supports. The radiators are integrally formed with cross-braces, and are fed with manifold feed straps incorporating tuning paddles. A single cylindrical radome surrounds the radiative parts and the vertical supports. The antenna admits of application to the upper L-band at the full FCC-allowed ERP. Beam tilt, null fill, and vertical null can be readily accommodated.

Abstract: A circularly polarized patch antenna uses a square quarter-wavelength conductive plate, spaced away from a slightly larger backing conductor. Excitation uses a coaxial feed stem pair, whereof respective inner conductors join the patch at orthogonal locations on a reference circle, and outer conductors intrude past points of joining to the backing conductor to establish gaps that interact with patch and backing conductor size and spacing to jointly establish terminal impedance. A parasitic element in the propagation path broadens bandwidth, while a frame behind serves to define a cavity reflector. A power divider behind the frame converts a single applied broadcast signal into two equal signals with orthogonal phase, which signals are delivered to the feed stems with equal-length coaxial lines.

Abstract: A vertically polarized traveling wave antenna is omnidirectional, bottom-mounted, and bottom-fed. A robust center coax provides a self-supporting mechanical structure. Multiple dipoles are capacitively coupled to the coax in quads, with a first two dipoles placed on opposite sides of the center coax and spaced by a quarter wavelength along the coax from the second two, which couple at right angles to the first two. This matched-layer spacing cancels the reactive components of the impedances of the dipoles. Beam tilt is readily incorporated over a wide range by adjusting layer spacing to add phase taper. All dipoles are oriented parallel to the coax axis, with opposite “hot” (center coupled) dipole elements oriented oppositely to each other. A radiated signal thus has rotating phase, when viewed from above, but is vertically polarized at each azimuth. A lightweight radome, provided for weather protection, is not needed for structural integrity.

Abstract: A vertically polarized traveling wave antenna is omnidirectional, bottom-mounted, and bottom-fed. A robust center coax provides a self-supporting mechanical structure. Multiple dipoles are capacitively coupled to the coax in quads, with a first two dipoles placed on opposite sides of the center coax and spaced by a quarter wavelength along the coax from the second two, which couple at right angles to the first two. This matched-layer spacing cancels the reactive components of the impedances of the dipoles. Beam tilt is readily incorporated over a wide range by adjusting layer spacing to add phase taper. All dipoles are oriented parallel to the coax axis, with opposite “hot” (center coupled) dipole elements oriented oppositely to each other. A radiated signal thus has rotating phase, when viewed from above, but is vertically polarized at each azimuth. A lightweight radome, provided for weather protection, is not needed for structural integrity.

Abstract: A very inexpensive and on-site tunable design for a vertically polarized panel antenna system, suitable for the FCC digital broadcast 700 MHz range is provided. Bowtie-like shaped antennas having machine-stampable planar elements with an adjustable separation are configured with a stripline feed. The stipline feed enables easy feeding of doublet systems to allow the configuration of an array of vertically polarized antennas. The various components of the antenna system can be easily tuned, enabling rapid deployment and quick operation.

Abstract: A system for increasing isolation between analog and digital antennas suited for FM IBOC operations is provided, wherein an interleaved combination of dissimilar antennas are arrayed with an offset there between to obtain a desired performance the use of dissimilar antennas and an offset, several additional degrees of freedom are afforded to the broadcaster in obtaining the desired isolation between signals, and also for upgrading an existing analog system to IBOC capability.

Abstract: An antenna system and method using a folded panel antenna system with a bow-tie slot formed therein is arranged about a tower to provide greater azimuthal beamwidth coverage with increased gain. A groundplane is positioned to the rear of the folded panel, wherein a stripline feed is utilized for exictation of the antenna. A skewed parasitic dipole is attached to the front of the bow-tie slot to generate orthogonal field components for circular and/or ellipitic polarizations.

Abstract: A stub-loop based antenna doublet array having an offset feed and adjustably positioned stub-loops is provided that enables improved isolation of the horizontal versus vertical polarization characteristics from the impedance. Consequently, conventional VSWR adjustments or tuning can be accomplished without significantly impacting the polarization ratios or pattern.

Abstract: A monitoring system for an transmission line, such as a multi-channel television broadcasting antenna feed line, gathers data about the physical and electrical condition of the line in real time. The system can detect and localize deterioration and other time-dependent faults in the transmission line by the tendency of faults to produce reflections back to the transmitter that were not part of the original characterization of a particular installation. Some kinds of faults, identified early enough, can be corrected without replacing components, and especially without shutting down the transmission line during prime viewing hours. Other faults can be detected in time to order replacement parts before the underlying problem becomes severe, and to allow servicing during periods of low demand.

Abstract: Each of a pair of antennas for broadcasting has multiple elements arranged vertically on the same tower. The antennas transmit circularly polarized signals of opposite polarization. The opposite circular polarization of the radiated signals increases their mutual isolation and permits broadcast of conventional FM-band signals and digital FM at the same frequency. The polarization technique allows the elements of the two antennas to share an aperture without degradation of function.

Abstract: A directional antenna is disclosed that includes an inner conductor positioned within an outer conductor. The directional antenna includes multiple slots around the periphery of the antenna and efficiently dissipates energy received at the slot, and is able to generate a directional azimuth pattern.

Abstract: A directional antenna is disclosed that includes an inner conductor positioned within an outer conductor. The directional antenna includes multiple slots around the periphery of the antenna and efficiently dissipates energy received at the slot, and is able to generate a directional azimuth pattern.

Abstract: An antenna system is disclosed that includes a mast, waveguides positioned about the mast, and a feed system positioned external to the mast and between adjacent waveguides, such the feed system can be easily serviced. The waveguides include radiator elements that are easy to manufacture, and thus reduce the cost associated with wideband cavity-backed antennas. Further, adjustable disc-like and spherical radiating elements for exciting the fields in the waveguides are also disclosed. DC voltage buildup on the radiating elements are grounded by an easily attachable coaxial structure.

Abstract: Each of a pair of antennas for broadcasting has multiple elements arranged vertically on the same tower. The antennas transmit circularly polarized signals of opposite polarization. The opposite circular polarization of the radiated signals increases their mutual isolation and permits broadcast of conventional FM-band signals and digital FM at the same frequency. The polarization technique allows the elements of the two antennas to share an aperture without degradation of function.

Abstract: An antenna includes conductive panels pierced with bow-tie-shaped cutouts (long axis vertical) fed at the narrow point of the cutout to achieve horizontal polarization. Each two panels are configured at right angles as an ‘X’ when viewed from above. The radiation pattern from each panel is a peanut shape; with a hybrid phase shifter to feed each pair in quadrature, the combined pattern is omnidirectional. Multiple crossed-cutout modules can be arranged vertically and fed in parallel to achieve high vertical directivity. The general design permits outdoor application with no supporting mast. The general design is compatible with the power capability and frequency range needed for commercial UHF television broadcast.

Abstract: An antenna includes conductive panels pierced with bow-tie-shaped cutouts (long axis vertical) fed at the narrow point of the cutout to achieve horizontal polarization. Each two panels are configured at right angles as an ‘X’ when viewed from above. The radiation pattern from each panel is a peanut shape; with a hybrid phase shifter to feed each pair in quadrature, the combined pattern is omnidirectional. Multiple crossed-cutout modules can be arranged vertically and fed in parallel to achieve high vertical directivity. The general design permits outdoor application with no supporting mast. The general design is compatible with the power capability and frequency range needed for commercial UHF television broadcast.

Abstract: A slotted coaxial antenna design that accomplishes simultaneous DTV and NTSC broadcast with minimal tower windloading is disclosed. In a preferred embodiment, the antenna design includes a VHF slotted coaxial antenna that acts as a framework to house multiple UHF slotted coaxial antennas, wherein the beam tilt of each UHF antenna can be independently adjusted. The one or more UHF slotted coaxial antennas, which each acts as an UHF outer conductor, and the one or more VHF couplers, which surround the VHF inner conductor, configure an arrangement such that the UHF antennas and VHF couplers share a common aperture, namely, the VHF antenna. This antenna design allows for high band VHF/UHF broadcast of DTV and NTSC signals while being easily adaptable to existing slotted coaxial antennas.