Abstract: Balun with tunable bandpass filter characteristic includes first, second and third coupling elements disposed on a substrate. The first and second coupling elements are arranged on the substrate relative to the third coupling element to couple two identical but out of phase signals to form a corresponding unbalanced signal in the third coupling element. A plurality of tunable resonator elements are distributed within an area of the substrate defined on one side by the first and second coupling elements and on an opposing side by the third coupling element. The tunable resonator elements are configured to selectively produce a bandpass filter response.

Abstract: Balun with tunable bandpass filter characteristic includes first, second and third coupling elements disposed on a substrate. The first and second coupling elements are arranged on the substrate relative to the third coupling element to couple two identical but out of phase signals to form a corresponding unbalanced signal in the third coupling element. A plurality of tunable resonator elements are distributed within an area of the substrate defined on one side by the first and second coupling elements and on an opposing side by the third coupling element. The tunable resonator elements are configured to selectively produce a bandpass filter response.

Abstract: Directional coupler includes a first, second and third transmission lines. Each of the first and second transmission line elements is disposed on a dielectric substrate, and has a first end and a second end. At least a portion of the first and second transmission line elements are adjacent along a path. A third transmission line element is disposed along the path between the first and the second transmission line elements and separated therefrom by a portion of the dielectric substrate. The third transmission line element is electrically connected to a ground plane disposed on a surface of the dielectric substrate opposed from the first and second transmission line elements.

Abstract: Directional coupler includes a first, second and third transmission lines. Each of the first and second transmission line elements is disposed on a dielectric substrate, and has a first end and a second end. At least a portion of the first and second transmission line elements are adjacent along a path. A third transmission line element is disposed along the path between the first and the second transmission line elements and separated therefrom by a portion of the dielectric substrate. The third transmission line element is electrically connected to a ground plane disposed on a surface of the dielectric substrate opposed from the first and second transmission line elements.

Abstract: An improved distributed amplifier (200) includes an input transmission line (201) terminated with an input lead configured to accept an input signal and an output transmission line (202) terminated with an output lead configured to output an output signal. A number of parallel amplifier cells (204N) are connected to the input transmission line (201) and the output transmission line (202) that collectively amplify the input signal from the input lead to produce an amplified output signal at the output lead. A bypass switch (212, 300) is connected to the input and output transmission lines (201, 202). The bypass switch (212, 300) is operative to convert either the input transmission line (201, 301) or the output transmission line (202, 302) into a bypass line configured to bypass the parallel amplifier cells (204N) of the distributed amplifier (200) and provide a direct path between the input and output transmission lines (201, 202) to produce a bypassed output signal at the output lead.

Abstract: An improved distributed amplifier (200) includes an input transmission line (201) terminated with an input lead configured to accept an input signal and an output transmission line (202) terminated with an output lead configured to output an output signal. A number of parallel amplifier cells (204N) are connected to the input transmission line (201) and the output transmission line (202) that collectively amplify the input signal from the input lead to produce an amplified output signal at the output lead. A bypass switch (212, 300) is connected to the input and output transmission lines (201, 202). The bypass switch (212, 300) is operative to convert either the input transmission line (201, 301) or the output transmission line (202, 302) into a bypass line configured to bypass the parallel amplifier cells (204N) of the distributed amplifier (200) and provide a direct path between the input and output transmission lines (201, 202) to produce a bypassed output signal at the output lead.

Abstract: A tunable impedance inverter is presented for a Doherty amplifier circuit having first and second amplifiers connected in parallel between an input circuit for receiving an input signal and an output circuit for supplying an output signal to a load. An impedance inverter is coupled between the first amplifier and the output circuit. The inverter has an input and an output and a tunable mechanical strip line of variable electrical length interposed between the input and the output. An adjuster adjusts the electrical length of the strip line. The adjuster adjustably varies the electrical length of said pathway to thereby adjust the center frequency of said output signal.

Abstract: A 180° hybrid coupler (100) includes a first transmission line transformer (101) and a second transmission line transformer (102). Each of the first and second transmission line transformers is comprised of a coplanar stripline structure disposed in a spiral configuration. Each of the coplanar stripline structures has a first characteristic impedance and is configured to function as a balun. A common input feed (202) is coupled to each of the first and second transmission line transformers. A third transmission line transformer (103) and a fourth transmission line transformer (104) are also provided. Each of the third and fourth transmission line transformers is also configured to function as a balun and is coupled to the first and second transmission line transformers.

Abstract: A radio frequency (RF) directional coupler (100) can include a first transmission line element (102) having a first end and a second end, and a second transmission line element (104) having a first end and a second end. The first and second transmission line elements (102, 104) can be disposed in a first plane, where at least a portion of said first and said second transmission line elements (102, 104) are adjacent along a path. The RF coupler (100) can also include a first series of conductive coupling elements (116) disposed along said path in a second plane parallel to the first plane and separated from said first and said second transmission line elements (102, 104) by a first dielectric element (114). The first and second plane can be separated by a pre-determined distance (t2) to increase a capacitive coupling between the first and second transmission line elements (102, 104).

Abstract: Methods for compensating for phase shifts of a communication signal. The methods involve determining a first reference signal (Vref-1) at a first location along a transmission path and a second reference signal (Vref-2) at a second location along the transmission path. Vref-2 is the same as Vref-1. At the first location, a first phase offset is determined using Vref-1 and a first communication signal. At the second location, a second phase offset is determined using Vref-2 and a second communication signal. A phase of a third communication signal is adjusted at the second location using the first and second phase offsets to obtain a modified communication signal. The first, second, and third communication signals are the same communication signal obtained at different locations along the transmission path.

Abstract: Systems comprising sensing devices (SD), a signal combiner (SC), signal subtractors (SS), and signal multipliers (SM). SD (116, 402, 504, 604, 620, 708a, 708b, 708c) senses at a first location along a transmission media (TM) a first signal (Vf) propagated over TM (100, 502, 602, 702, 1025) in a forward direction and a second signal (Vr) propagated over TM in a reverse direction opposed from the forward direction. SC (406, 508, 606, 806) computes a Sum signal (S) by adding Vf and Vr together. A first SS (408, 508, 606, 806) computes a Difference signal (D) by subtracting Vr from Vf. A first SM (410, 510, 608a, 808a) computes a first Exponentiation signal (ES) using S. A second SM (412, 512, 608b, 808b) computes a second Exponentiation signal (ED) using D. A second SS (414, 514, 614, 816) subtracts ES from ED to obtain a reference signal (Vref).

Abstract: A 180° hybrid coupler (100) includes a first transmission line transformer (101) and a second transmission line transformer (102). Each of the first and second transmission line transformers is comprised of a coplanar stripline structure disposed in a spiral configuration. Each of the coplanar stripline structures has a first characteristic impedance and is configured to function as a balun. A common input feed (202) is coupled to each of the first and second transmission line transformers. A third transmission line transformer (103) and a fourth transmission line transformer (104) are also provided. Each of the third and fourth transmission line transformers is also configured to function as a balun and is coupled to the first and second transmission line transformers.

Abstract: A radio frequency (RF) directional coupler (100) can include a first transmission line element (102) having a first end and a second end, and a second transmission line element (104) having a first end and a second end. The first and second transmission line elements (102, 104) can be disposed in a first plane, where at least a portion of said first and said second transmission line elements (102, 104) are adjacent along a path. The RF coupler (100) can also include a first series of conductive coupling elements (116) disposed along said path in a second plane parallel to the first plane and separated from said first and said second transmission line elements (102, 104) by a first dielectric element (114). The first and second plane can be separated by a pre-determined distance (t2) to increase a capacitive coupling between the first and second transmission line elements (102, 104).

Abstract: A method and apparatus is provided for forming a printed circuit board or other panel in which an array of vias are arranged in a desired connection grid within one or more layers of the board and then the board and vias are cut to form an edge of the board where a surface of the vias is exposed. The board may be orthogonally mounted on its edge to another thin circuit board or aperture sheet with the exposed surface of each via directly connected to such other board or sheet.

Abstract: An antenna includes antenna elements, an antenna feed assembly and at least one integrated circuit adjacent the antenna feed assembly on a side thereof opposite the antenna elements. The at least one integrated circuit is connected to the antenna elements via the antenna feed assembly. The antenna feed assembly includes a conductive base plate spaced from the antenna elements, and has feed openings therein. Spaced apart conductive posts are integrally formed with the conductive base plate as a monolithic unit, and extend outwardly therefrom toward the antenna elements. Each conductive post has at least one passageway therethrough aligned with at least one respective feed opening to define at least one antenna feed passageway. A respective elongated feed conductor extends through each antenna feed passageway.

Abstract: An object tracking system for locating radio-tagged objects within a monitored environment has a plurality tag transmission readers that detect RF transmissions from the tags, and generate output signals representative of the time-of-arrival of first-to-arrive tag transmissions. An object location processor processes the first to arrive signals in accordance with a multilateration algorithm to geolocate a tag. In order to modify the operation of a tag that comes within a prescribed region of the monitored environment (such as passing through a doorway), one or more relatively short range, magnetic field proximity-based, tag-programming ‘pingers’, are placed proximate to the region. A magnetic field receiver on the tag detects the field generated by the pinger and causes the tag to change operation such as increase its RF transmission rate.

Abstract: Magnetic field-based communication with an object is enhanced by generating a rotating AC magnetic field that effectively ensures magnetic field coupling with the magnetic field sensor of the object, irrespective of the orientation of the object. The rotating AC magnetic field is produced by a diverse spatial orientation (a two-dimensional arrangement) of a plurality of magnetic field coils, and the driving of those coils in a prescribed phase relationship (e.g., in phase quadrature) to realize a composite AC magnetic field that rotates (at the carrier frequency of the coil drive signal) over the entirety of the spatial coverage area.

Abstract: Magnetic field-based communication with an object is enhanced by generating a rotating AC magnetic field that effectively ensures magnetic field coupling with the magnetic field sensor of the object, irrespective of the orientation of the object. The rotating AC magnetic field is produced by a diverse spatial orientation (a two-dimensional arrangement) of a plurality of magnetic field coils, and the driving of those coils in a prescribed phase relationship (e.g., in phase quadrature) to realize a composite AC magnetic field that rotates (at the carrier frequency of the coil drive signal) over the entirety of the spatial coverage area.

Abstract: An amplitude modulation (AM) based mechanism controllably alters the shape of a binary phase shift keyed (BPSK) digital spreading waveform modulated onto an RF carrier. The modulated RF carrier is amplified by a saturated RF amplifier. The spectral properties of the amplified AM-BPSK waveform, when combined with the spectral properties of a BPSK waveform modulated onto the RF carrier and amplified by another saturated RF amplifier, produces a composite BPSK-modulated RF waveform containing substantially suppressed sidelobes.

Abstract: The unwanted influence a noise-source environment upon a modulated (e.g., FSK-encoded) magnetic field-based communication system is diminished by a non-modulated AC magnetic field communication scheme that uses a demodulatorless magnetic field detector. When installed in a tag to be tracked by a geolocation system, the demodulatorless detector responds when the tag comes within a prescribed proximity of the field generator producing the non-modulated AC magnetic field. The received signal is downconverted to baseband and processed to detect a valid AC magnetic field tone and indicate whether the tag is within a prescribed proximity of the AC magnetic field source.