A repeater and associated method of use includes at least one antenna element for communicating in one direction and at least one antenna element for communicating in another direction. A radio frequency uplink path and a radio frequency downlink path are coupled between the antennas. At least one of the radio frequency uplink path or the radio frequency downlink path includes an adaptive cancellation circuit. The adaptive cancellation circuit is configured to generate a cancellation signal without requiring an injected signal. The cancellation signal, when added to a radio frequency signal in the respective uplink and downlink paths, substantially reduces feedback signals present in the radio frequency signal.

Repeaters for wireless communication systems

The present invention provides a dielectric resonator antenna comprising: a dielectric resonator; a ground plane, operatively coupled with the dielectric resonator, the ground plane having four slots; and a substrate, operatively coupled to the ground plane, having a feeding network consisting of four microstrip lines; wherein the four slots are constructed and geometrically arranged to ensure proper circular polarization and coupling to the dielectric resonator; and wherein the antenna feeding network combines the four microstrip lines with a 90 degree phase difference to generate circular polarization over a wide frequency band.

Wideband circularly polarized hybrid dielectric resonator antenna

Signal coupling arrangements are described in which the effect of unwanted signals transferred between two antennas is compensated for. In one arrangement a microstrip edge coupler is used as a compensation network to provide a cross-coupling path for the transfer of a compensating signal between two antenna signal paths. In another arrangement, an antenna assembly includes cross-slots which, in association with a conductive ring, provide two mutually orthogonally polarised radiation signals and connections to the conductive ring have closely spaced portions which provide compensation for and minimise the effect of unwanted mutual coupling.

Signal coupling methods and arrangements

A region in a metallic panel that facilitates the transmission of radio frequency signals. The metallic panel may be included in a window such as the window of a vehicle or building. For example, the metallic panel may be used for heating or to reflect infrared radiation. An aperture is formed in the metallic panel to enable radio frequency signals to be transmitted through the metallic panel. The design of the aperture may be selected to enable the transmission of the desired frequency band. Furthermore, the aperture is designed such that there is a taper in the transmission amplitude and/or the phase to suppress lobing effects on the other side of the aperture. In an embodiment in which the metallic panel is used to conduct electric current, the aperture may be oriented such that the current may flow between the openings of the aperture. Accordingly, there may be uniform heating across the metallic panel without blocking the transmission of radio frequency signals in the desired frequency band.

Sidelobe controlled radio transmission region in metallic panel

Marking information relating to use of a marking device to perform a marking operation may be acquired from one or more input devices, logged/stored in local memory of a marking device, formatted in various manners, processed and/or analyzed at the marking device itself, and/or transmitted to another device (e.g., a remote computer/server) for storage, processing and/or analysis. In one example, a marking device may include one or more environmental sensors and/or operational sensors, and the marking information may include environmental information and operational information derived from such sensors. Environmental and/or operational information may be used to control operation of the marking device, assess out-of-tolerance conditions in connection with use of the marking device, and/or provide alerts or other feedback. Additional enhancements are disclosed relating to improving the determination of a location (e.g., GPS coordinates) of a dispensing tip of the marking device during use, a group/solo mode, and tactile functionality of a user interface.

Marking apparatus having enhanced features for underground facility marking operations, and associated methods and systems

A multi-band receiver for use with satellite ranging systems is provided. The receiver has a simplified architecture in which input signals of various frequencies are multiplexed together to form a single composite analog signal. In accordance with one embodiment of the invention, this composite signal only requires a single RF circuit for down conversion to an intermediate frequency. The composite, downconverted signal is sampled, and the digitized samples are demultiplexed to form digital counterparts of the original signals from each frequency band. An embodiment for use with elements of a phased array antenna is also provided.

Spatial and time multiplexing of multi-band signals

A planar, phased-array antenna (50) including a nonconductive substantially planar substrate and a transmission line (61) disposed on one surface is disclosed, a segment of the transmission line forming an arc of radius R centered on the antenna axis (51). A conductive layer on the other antenna surface includes two or more slotted openings (53, 55, 57, 59), each slotted opening having one end located within a distance R of the antenna axis, such that, when an electromagnetic signal is fed into one end of the transmission line, electromagnetic energy is sequentially coupled into the slotted openings, and a circularly-polarized signal is radiated from the antenna substantially in the direction of the antenna axis. An amplifier (71) or a connector may be electrically connected to one or both ends of the transmission line, or one end of the transmission line may be terminated in an impedance load (73) to form a leaky-wave antenna. The slotted openings may comprise either or both straight and curved segments, and may be of the same or unequal lengths. Curved slotted openings may be oriented clockwise or counter-clockwise to transmit or receive either left-handed or right-handed polarized signals.

Aperture coupled slot array antenna

This practical resource provides a current and comprehensive treatment of GPS/GNSS antennas, taking into account modernized systems and new and developing applications. The book presents a number of key applications, describing corresponding receiver architectures and antenna details. You find important discussions on antenna characteristics, including theory of operation, gain, bandwidth, polarization, phase center, mutual coupling effects, and integration with active components. Moreover, you get expert guidance on the design of adaptive arrays and signal processing techniques used to mitigate interference such as jamming. Addressing critical GNSS antenna high precision requirements, this in-depth book explains the relationships between antenna gain, satellite visibility, geometric dilution of precision, and the carrier-to-noise density ratio. The book delineates requirements for both dual-band and tri-band antennas. You get detailed coverage of a wide range of antenna designs, including microstrip patch, quadrafilar helix, axial mode helix, spiral, inverted L, and planar inverted F antennas. Moreover, you find a discussion on new magnetic metamaterialu substrates and other dielectric substrate materials. Further, this comprehensive book presents designs for very compact GNSS antennas for personal handheld devices and automobiles.

GPS/GNSS Antennas

A GPS-inertial system that is suited to new installations as well as the retrofitting of GPS receivers includes inertial sensors that are incorporated into the housing of the GPS antenna. The outputs of the inertial sensors are modulated onto a radio frequency carrier that has the same frequency as the GPS carrier, using the same data modulation arrangement as that used by the GPS system. The inertial measurements are thus sent to the receiver on the same cable as the RF signals from the antenna, and the receiver recovers the data from the sensor signals with the same arrangement that is used for data recovery from GPS position signals. Consequently, software modifications of existing GPS receivers can provide position and velocity estimates generated from the outputs of the inertial sensors.

Integrated gps-inertial system

A slot-array antenna includes a nonconductive substantially planar substrate and a transmission line disposed on a rear substrate surface where one end of the transmission line is connected to an amplifier, a connector, or an impedance load. A conductive layer on the front substrate surface includes a plurality of slotted openings arrayed about an antenna axis. A surface-wave suppression region encloses the array of slotted openings and a plurality of peripheral openings are disposed between the surface-wave suppression region and the peripheral edge of the antenna.

Waldemar Kunysz

Papers

Spatial and time multiplexing of multi-band signals

Aperture coupled slot array antenna

GPS/GNSS Antennas

Integrated gps-inertial system

Slot array antenna with reduced edge diffraction