Using A Comparison Or Difference Circuit Patents (Class 324/647)
  • Patent number: 7518129
    Abstract: A method for identifying a drifted dose integrator in an implantation system and an implantation system are provided. The implantation system includes a first dose integrator and a second dose integrator. The first dose integrator includes a first input configured to receive a first current generated from charges carried by implanted ions in a wafer, and a first output configured to output a first accumulated dosage value. The second dose integrator includes a second dose integrator including a second input configured to receive a second current generated from the charges carried by the implanted ions in the wafer, and a second output configured to output a second accumulated dosage value. The implantation system further includes a processing unit comparing the first accumulated dosage value and the second accumulated dosage value to detect a drift in one of the first and the second dose integrators.
    Type: Grant
    Filed: May 3, 2006
    Date of Patent: April 14, 2009
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Jih-Hwa Wang, Otto Chen, Fang-Chi Chien, Tung-Li Lee, Pu-Fang Chen
  • Patent number: 7514269
    Abstract: The invention is directed to a spectrometer for measuring submillimeter absorption. The spectrometer may include a solid state exciter generating a submillimeter wave and sweeping a predetermined frequency band, a frequency marker generating unit electrically generating frequency markers, a sample cell to contain a gas, and a solid-state detector detecting a submillimeter absorption of the gas. A spectrometer energizes a solid-state oscillator to generate a submillimeter wave and to sweep a predetermined band of frequency. The submillimeter wave is introduced into a sample cell containing a gas and frequency markers that are electrically generated during the sweep. Outputs of a solid-state detector disposed in the sample cell are read and recorded as a function of time and with the frequency markers. The recorded outputs of the solid-state detector are converted into a function of frequency using the recorded frequency markers.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: April 7, 2009
    Assignee: Smart Transitions, LLC
    Inventor: Keith W. Reiss
  • Publication number: 20080211518
    Abstract: An apparatus (2) for measuring electrical conductivity in a material comprises a pair of electrically conducting elements (6), a first electrical conductor (9) coupled to the electrically conducting elements, the first electrical conductor coupling a first transformer core (10) and a second transformer core (12) to form a first current loop (8) and a second electrical conductor (17) of known resistance coupling the second transformer core and a third transformer core (14) to form a second current loop (16).
    Type: Application
    Filed: January 14, 2005
    Publication date: September 4, 2008
    Inventors: Nigel Harold Hancock, Andrew Douglas Maxwell, Antonio Louis Ah Fock
  • Publication number: 20080204044
    Abstract: An exemplary method comprises the steps of introducing a reactive current reference square wave, detecting load voltage changes at every change in the reactive current reverence wave, and determining whether the detected load voltage changes exceed a predefined islanding detection threshold value, indicating a loss of mains and an islanding operation of the power generator. With the exemplary loss-of-mains detection, islanding can be detected within a shortest period of time, even if the local islands active and reactive load matches exactly the distributed generators active and reactive power generation. So even without a sudden voltage change, unintentional islanding can immediately be detected and control electronics can safely turn of the distributed power generator.
    Type: Application
    Filed: March 18, 2008
    Publication date: August 28, 2008
    Applicant: ABB Schweiz AG
    Inventors: Srinivas Ponnaluri, Beat Ronner
  • Patent number: 7411514
    Abstract: The failure detecting apparatus includes an input circuit 13 connected to a temperature sensor 53 to detect various changes, for detecting the resistance of the temperature sensor 53, a monitor circuit 14 connected in parallel to the input circuit 13 for monitoring the failure of the input circuit 13, and a CPU 1 which is supplied with the resistance of the temperature sensor 53 detected by the input circuit 13 and in detecting failure of the monitor circuit 14, switches its state between the inputting state receiving a signal from the monitor circuit 14 and the outputting state sending the signal to the monitor circuit 14.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: August 12, 2008
    Assignee: Mitsuba Corporation
    Inventor: Keiichi Enomoto
  • Patent number: 7309994
    Abstract: A directional bridge for measuring propagated signals to and from a source device to a load device where both the source device and load device are in signal communication with the directional bridge is disclosed. The directional bridge may include a first bridge circuit network and a first sensing element in signal communication with the first bridge circuit network. The first sensing element may produce a first measured signal that is proportional to the propagated signals.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: December 18, 2007
    Assignee: Agilent Technologies, Inc.
    Inventors: Eric R. Ehlers, Craig Hutchinson, Richard L. Rhymes, Timothy E. Shirley, Bobby Y. Wong
  • Patent number: 7279908
    Abstract: A differential signaling system is provided. The differential signaling system comprises one or more cable pairs for carrying signals, one or more differential drivers for providing signals to the one or more cable pairs, and one or more differential receivers, the one or more differential receivers being coupled to the one or more differential drivers via the one or more cable pairs. The differential signaling system further comprises one or more test devices for testing the differential signaling system, and at least one switch coupled to at least one of the one or more cable pairs and to at least one of the one or more test devices, the switch being adapted to dynamically switch the at least one of the one or more test devices into a differential interface of the differential signaling system.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: October 9, 2007
    Assignee: Honeywell International Inc.
    Inventor: Christopher L. Blake
  • Patent number: 7216051
    Abstract: A technique for testing an electronics assembly for a power short circuit is provided. The technique includes pre-characterizing power off resistance of an electronic component(s) of a first packaging level from at least one power boundary of the electronic component(s). The characterizing of the power off resistance occurs prior to placement of the electronic component(s) into an electronics assembly of a higher packaging level. The technique further includes determining actual power off resistance of the electronics component(s) after placement thereof into the electronics assembly, with the actual power off resistance being determined from the at least one power boundary. Thereafter, the actual power off resistance of the electronic component(s) in the electronics assembly is compared with the pre-characterized power off resistance of the at least one electronic component(s), and a determination is made therefrom whether a power short circuit exists within the electronics assembly.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: May 8, 2007
    Assignee: International Business Machines Corporation
    Inventors: Frank E Bosco, Gerald J. Fahr, Raymond A. Longhi, Vincent P. Mulligan
  • Patent number: 7123025
    Abstract: There is provided a differential comparator circuit that is mounted on a test apparatus for testing a device under test outputting differential signals including noninverted signals and inverted signals. The differential comparator circuit includes: a difference signal subtracting circuit operable to compute and output a difference signal indicative of a difference between the noninverted signal and the inverted signal; a first threshold value subtracting circuit operable to compute and output a first threshold voltage indicative of a difference between a first comparative voltage generated based on ground potential of the device under test and a reference voltage generated based on the ground potential of the device under test; and a first comparing circuit operable to compare the difference signal and the first threshold voltage to output a comparison result.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: October 17, 2006
    Assignee: Advantest Corporation
    Inventors: Toshiaki Awaji, Takashi Sekino
  • Patent number: 6914555
    Abstract: A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically isolated from the first electrode and disposed at the distal tip of the probe. An oscillating signal is transmitted through the first electrode, and at least a portion of the signal is received through the second electrode. Through changes in the received signal due to the distal tip of the probe coming into contact with a fluid surface or due to fluid flow through the conduit between the first and second electrodes, fluid surface contact and fluid flow can be detected. A pressure sensor can be employed to monitor internal fluid pressure within the fluid conduit of the fluid delivery probe as a secondary, redundant mechanism for detecting fluid flow through the conduit.
    Type: Grant
    Filed: May 1, 2003
    Date of Patent: July 5, 2005
    Assignee: Gen-Probe Incorporated
    Inventors: James H. Lipscomb, Anna Jurik, Bernard Katz, Michael J. Keating, Stone Klengler, John J. Kotlarik, Mieczyslaw Wroblewski, Larry Jurik
  • Patent number: 6851453
    Abstract: A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically isolated from the first electrode and disposed at the distal tip of the probe. An oscillating signal is transmitted through the first electrode, and at least a portion of the signal is received through the second electrode. Through changes in the received signal due to the distal tip of the probe coming into contact with a fluid surface or due to fluid flow through the conduit between the first and second electrodes, fluid surface contact and fluid flow can be detected. A pressure sensor can be employed to monitor internal fluid pressure within the fluid conduit of the fluid delivery probe as a secondary, redundant mechanism for detecting fluid flow through the conduit.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: February 8, 2005
    Assignee: Gen-Probe Incorporated
    Inventors: James H. Lipscomb, Anna Jurik, Bernard Katz, Michael J. Keating, Stone Klengler, John J. Kotlarik, Mieczyslaw Wroblewski, Larry Jurik
  • Patent number: 6801043
    Abstract: According to some embodiments, time domain reflectometry based transmitter equalization is provided. For example, a reflection detector in a transmitter may detect a reflection signal associated with a calibration signal that was transmitted via an interconnect. The reflection detector may then provide filter information to a transmitting unit to facilitate a transmission of data to a remote receiver via the interconnect. According to some embodiments, the receiver adjusts a termination impedance before the calibration signal is transmitted.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: October 5, 2004
    Assignee: Intel Corporation
    Inventors: Alok Tripathi, Ken Drottar
  • Patent number: 6791340
    Abstract: A device for the comparison of two resistors is based upon analog information carried by currents. The device includes a measurement circuit for extracting the currents from the two resistors to be compared, and copies the currents to a parallel analog-digital converter that carries out the division of the extracted currents. The device converts the ratio of the extracted currents into a digital code that is the image of the ratio of the two resistors. The ratio is constantly re-updated as a function of environmental parameters of the circuit, such as the operating temperature. Also disclosed is a system for correcting the value of integrated compensated resistors. The system implements a device of this kind that does not use a reference voltage generator.
    Type: Grant
    Filed: June 12, 2002
    Date of Patent: September 14, 2004
    Assignee: STMicroelectronics SA
    Inventor: Frédéric Hasbani
  • Publication number: 20040135586
    Abstract: An improved system for determining the value of a resistive load is provided. The system includes: a reference voltage source; a reference resistor of known value having a first and second terminal, the first terminal connected to the reference voltage source and the second terminal connected to the resistive load; and a software program stored in a control unit connected to the first and second terminal, the control unit operative to read a value of the reference voltage source and a voltage at the second terminal of the predetermined reference resistor and to calculate the value of the resistive load as a function of the readings of the reference voltage source and the second terminal voltages.
    Type: Application
    Filed: January 15, 2003
    Publication date: July 15, 2004
    Inventors: Mikhail Zarkhin, Timothy P. Philippart, Roger A. Moon
  • Patent number: 6633171
    Abstract: A comparison circuit for comparing the desired voltage levels of electronic components and for disabling the supply of power to those components if the desired voltage levels are not equivalent. The comparison circuit receives the desired voltage level indication signals and provides a signal indicating whether the desired voltage levels are equivalent. If the desired voltage levels are not equivalent, the comparison circuit provides a signal indicating non equivalency to a power supply, wherein the power supply is disabled from supplying power so as not to damage the computer components from receiving power at a non allowable voltage level. The comparison circuit also provides an output signal indicative of an equivalent voltage level to the desired voltage levels if the desired voltage levels are equivalent. A power supply converter supplies power to the components at a voltage level as indicated by the output signal.
    Type: Grant
    Filed: March 26, 2001
    Date of Patent: October 14, 2003
    Assignee: Dell Products L.P.
    Inventors: Alan E. Brown, Steven J. Lash
  • Patent number: 6630833
    Abstract: Systems, methods, and probe devices for electronic monitoring and characterization using absorbent media confined by a metallic mesh. The mesh allows a stream of liquid or gas to pass through the structure, so that the media will adsorb the material to which it is specific. This changes the permittivity of the media in which the electromagnetic field is propagating. This change in permittivity can be seen through the use of classical microwave methods such as phase shift, amplitude changes, frequency changes in a cavity or the frequency of an unbuffered oscillator. Some embodiments use a two cylinder structure, where an outer cylinder contains a material which selectively removes a chemical which may be in conflict with or would contaminate the sensing of the desired chemical. This outer cylinder does not play a part in the measurement because it is outside the metal shield which contains the measurement adsorbent, and is thus outside the electromagnetic field.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: October 7, 2003
    Assignee: Phase Dynamics, Inc.
    Inventor: Bentley N. Scott
  • Patent number: 6614240
    Abstract: Determinations are made related to the presence of a predetermined material in concrete under test using previously obtained model information. In one embodiment, the predetermined material includes a chloride material and the model information is obtained using a number of cured cement specimens. The model information is stored in memory, such as in the form of a look-up table. When the concrete is being inspected, one or more magnitudes of reflections coefficients are measured and such is utilized with the model information to make determinations related to the presence of the predetermined material. In developing the model information, each of the plurality of cured cement specimens is located in a bath containing the predetermined material. The bath may be pressurized. The cured cement specimens are maintained in the bath for different, known time intervals. After the known time interval for a particular specimen, it is dried and one or more magnitudes of reflection coefficients are measured.
    Type: Grant
    Filed: July 16, 2001
    Date of Patent: September 2, 2003
    Assignee: Colorado State University Research Foundation
    Inventors: Reza Zoughi, Aaron D. Benally, Karl J. Bois, Kimberly Kurtis
  • Patent number: 6604054
    Abstract: A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically isolated from the first electrode and disposed at the distal tip of the probe. An oscillating signal is transmitted through the first electrode, and at least a portion of the signal is received through the second electrode. Through changes in the received signal due to the distal tip of the probe coming into contact with a fluid surface or due to fluid flow through the conduit between the first and second electrodes, fluid surface contact and fluid flow can be detected. A pressure sensor can be employed to monitor internal fluid pressure within the fluid conduit of the fluid delivery probe as a secondary, redundant mechanism for detecting fluid flow through the conduit.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: August 5, 2003
    Assignee: Gen-Probe, Inc.
    Inventors: James H. Lipscomb, Larry Jurik, Bernard Katz, Michael J. Keating, Stone Klengler, John J. Kotlarik, Mieczyslaw Wroblewski
  • Patent number: 6573731
    Abstract: A method and system for measuring at least one of a plasma density and an electron density (e.g., in a range of 1010 to 1012 electrons/cm−3) using plasma induced changes in the frequency of a microwave oscillator. Measurement of at least one of the plasma density and the electron density enables plasma-assisted processes, such as depositions or etches, to be controlled using a feedback control. Both the measurement method and system generate a control voltage that in turn controls a plasma generator to maintain at least one of the plasma density and the electron density at a pre-selected value.
    Type: Grant
    Filed: April 9, 2002
    Date of Patent: June 3, 2003
    Assignee: Tokyo Electron Limited
    Inventors: Joseph T. Verdeyen, Wayne L. Johnson, Murray D. Sirkis
  • Patent number: 6535785
    Abstract: A system and method for monitoring the conditions in a gas plasma processing system while varying or modulating the RF power supplied to the system, so that resulting signals of the electrical circuits of the system provide information regarding operational parameters of the system or the state of a process. Significant improvements in sensitivity and accuracy over conventional techniques are thereby achieved. In addition, the plasma processing system can be thoroughly tested and characterized before delivery, to allow more accurate monitoring of and greater control over a process, thereby improving quality control/assurance of substrates being produced by the system. The information obtained by the modulation technique can be displayed on a monitor screen, in order to allow an operator to accurately monitor the system/process and diagnose any problems with the system/process.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: March 18, 2003
    Assignee: Tokyo Electron Limited
    Inventors: Wayne Johnson, Richard Parsons
  • Patent number: 6512380
    Abstract: A contactor includes a switching circuit for switching a load between one or more electrical supplies, a current detector for detecting the current flowing through the load, a trip circuit for tripping the current after an interval of time which depends upon how much the current flowing through the load exceeds a predetermined amount, and a pre-trip circuit for providing an indication during said time interval that the current exceeds said predetermined amount for providing ‘pre-trip’ or ‘near-trip’ information.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: January 28, 2003
    Assignee: Lucas Industries Limited
    Inventor: Simon Turvey
  • Publication number: 20020070733
    Abstract: A voltage measurement apparatus is provided for measuring a voltage of each of N power sources connected in series. The apparatus includes N capacitance elements provided respectively corresponding to the N power sources, and connected in series, a first switching section for simultaneously applying a voltage of each power source to one of the N capacitance elements corresponding to said power source, a voltage measurement section for measuring a voltage of each capacitance element, and a second switching section for sequentially connecting each capacitance element to the voltage measurement section.
    Type: Application
    Filed: October 31, 2001
    Publication date: June 13, 2002
    Inventors: Masahiro Takada, Naohisa Morimoto
  • Patent number: 6384590
    Abstract: In a light receiving circuit for use in electro-optic sampling oscilloscope which receives first and second optical, photodiodes 51 and 52 are connected in series between a positive bias power supply 50P and a negative bias power supply 50N. The photodiodes 51 and 52 receive optical signals whose polarization state correspond to the voltage of a signal to be measured and convert the thus-received optical signals into electric signals. An amplifier 53 amplifies an electric current appearing in a point of connection P between the photodiodes 51 and 52. A current monitor 54 detects the electric signal converted by the photodiode 51, and a current monitor 57 detects the electric signal converted by the photodiode 52. The electric signal detected by the current monitor 54 is subjected to analog-to-digital conversion by an analog-to-digital converter 55, and the electric signal detected by the current monitor 57 is subjected to analog-to-digital conversion by an analog-to-digital converter 58.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: May 7, 2002
    Assignees: Ando Electric Co., Ltd., Nippon Telegraph and Telephone Corporation
    Inventors: Jun Kikuchi, Nobuaki Takeuchi, Yoshiki Yanagisawa, Nobukazu Banjo, Yoshio Endou, Mitsuru Shinagawa, Tadao Nagatsuma, Junzo Yamada
  • Patent number: 6373262
    Abstract: A transmission line for carrying digital signals is provided with auxiliary line drivers at the receiver end, which are used in combination with the data line driver at the transmitting end to apply a sequence of sets of test voltages onto the line. The voltage resulting at the receiver input is used to detect open signal conductors and/or shorts in the receiver.
    Type: Grant
    Filed: February 17, 2000
    Date of Patent: April 16, 2002
    Assignee: International Business Machines Corporation
    Inventors: Jay R. Herring, Joseph M. Hoke, Robert R. Livolsi, Robert J. Lynch, Steven Makow, Andrew Z. Muszynski
  • Patent number: 6351683
    Abstract: A system and method for monitoring the conditions in a gas plasma processing system while varying or modulating the RF power supplied to the system, so that resulting signals of the electrical circuits of the system provide information regarding operational parameters of the system or the state of a process. Significant improvements in sensitivity and accuracy over conventional techniques are thereby achieved. In addition, the plasma processing system can be thoroughly tested and characterized before delivery, to allow more accurate monitoring of and greater control over a process, thereby improving quality control/assurance of substrates being produced by the system. The information obtained by the modulation technique can be displayed on a monitor screen, in order to allow an operator to accurately monitor the system/process and diagnose any problems with the system/process.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: February 26, 2002
    Assignee: Tokyo Electron Limited
    Inventors: Wayne Johnson, Richard Parsons
  • Patent number: 6348801
    Abstract: A method and a communications device are described, comprising a radio telephone (5) with connected antenna path (1) which can be used to locate precisely a defective area (F) in the antenna path (1) in order to be able to repair the antenna path (1) in a selective fashion. For this purpose, initially a wave with a starting frequency (f0) is coupled into the antenna path (1), and the amplitude of the standing wave at an angular position is measured. Then, the frequency of the wave is increased until a corresponding amplitude is detected at the same angular position. From the frequencies present then and from a reading (n) which indicates how often the corresponding amplitude has been obtained, the fault interval (Ed) between the detector (18) and defective area (F) is then calculated.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: February 19, 2002
    Assignee: Nokia Mobile Phones Ltd.
    Inventor: Andreas Pietsch
  • Patent number: 6339702
    Abstract: An output power detection circuit of a transmitter, which can accurately detect a power outputted from a power amplifier without depending on a change in ambient temperature is realized. The circuit comprises: a first diode to which a first bias direct current is applied; first load resistors through which the first bias direct current flows; a second diode to which a second bias direct current is applied; second load resistors through which the second bias direct current flows; and a differential amplifier. A first voltage generated in the first load resistor and a second voltage generated in the second load resistor are made substantially the same and are applied to the differential amplifier, a detection voltage obtained by detecting operation of the first diode is added to the first voltage, and a voltage corresponding to the power generated from a power amplifier is detected.
    Type: Grant
    Filed: February 1, 1999
    Date of Patent: January 15, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventor: Toru Izumiyama
  • Publication number: 20010047692
    Abstract: A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically isolated from the first electrode and disposed at the distal tip of the probe. An oscillating signal is transmitted through the first electrode, and at least a portion of the signal is received through the second electrode. Through changes in the received signal due to the distal tip of the probe coming into contact with a fluid surface or due to fluid flow through the conduit between the first and second electrodes, fluid surface contact and fluid flow can be detected. A pressure sensor can be employed to monitor internal fluid pressure within the fluid conduit of the fluid delivery probe as a secondary, redundant means for detecting fluid flow through the conduit.
    Type: Application
    Filed: February 28, 2001
    Publication date: December 6, 2001
    Inventors: James H. Lipscomb, Larry Jurik, Bernard Katz, Michael J. Keating, Stone Klengler, John J. Kotlarik, Mieczyslaw Wroblewski
  • Patent number: 6175239
    Abstract: A process and apparatus are provided to determine the characteristic impedance of a transmission line coupled to the output of a buffer. To achieve this, an output resistance of the buffer is initially set to a relatively high value to underdrive the transmission line. The output resistance of the buffer is then decreased until the buffer overdrives the transmission line. The characteristic impedance of the transmission line can then be determined from a ringback voltage which occurs due to the overdriving of the transmission line. In accordance with an embodiment of the invention, the ringback voltage can be detected by noting when a reference voltage is crossed twice during the same time of the driving pulse on the transmission line (the second crossing being the ringback voltage). The characteristic impedance of the transmission line can then be used to set the output resistance for the buffers on the operational buses.
    Type: Grant
    Filed: December 29, 1998
    Date of Patent: January 16, 2001
    Assignee: Intel Corporation
    Inventor: Stephen Hall
  • Patent number: 6104200
    Abstract: Time Domain Reflectometry ("TDR") methods and apparatus for measuring propagation velocities of RF pulses to determine material liquid contents, moisture profiles, material levels and dielectric constants including: i) TDR probes and/or probe adaptors, including series averaging probes and multi-segment probes, all employing remotely operable, normally open, variable impedance devices such as diodes; ii) bias insertion and switching networks for rendering selected normally open variable impedance devices conductive one at a time to establish precise unambiguous timing markers T.sub.1 . . . T.sub.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: August 15, 2000
    Assignee: Precision Moisture Instruments, Inc.
    Inventor: William R. Hook
  • Patent number: 5939889
    Abstract: An apparatus is disclosed for testing concrete having an unknown water/cement ratio and an unknown compressive strength. The apparatus includes a transmitter assembly for transmitting microwave signals at one or more predetermined frequencies. A receiver assembly receives each microwave signal reflected from the concrete under test. The reflected microwave signals, together with the transmitted microwave signals, are used to determine a reflection coefficient magnitude for the particular microwave frequency. A processing unit uses the reflection coefficient magnitude to determine a value related to concrete strength. In one embodiment, the processing unit relies on a logarithmic function that correlates the reflection coefficient magnitude and a water/cement ratio. A value related to the compressive strength of the concrete can also be obtained using the value of the water/cement ratio or the value of the reflection coefficient magnitude.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: August 17, 1999
    Assignee: Colorado State University Research Foundation
    Inventors: Reza Zoughi, Paul S. Nowak
  • Patent number: 5861757
    Abstract: An instrument for measuring the dielectric constant of samples with complex or uncertain geometries that can include unusually shaped single sample pieces or collections of differently shaped sample pieces such as powders. The premise of the measurement technique is that a reference capacitor plate and a sample capacitor plate are exposed to a dynamically-changing solvent mixture. When the capacitance of these two fixtures become equal at the point at which a particular solvent mixture is reached, the dielectric constant of the sample is then known.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: January 19, 1999
    Assignee: International Business Machine Corporation
    Inventors: Gareth Geoffrey Hougham, Alfred Viehbeck, Stanley Joseph Whitehair
  • Patent number: 5726578
    Abstract: Time Domain Reflectometry ("TDR") methods and apparatus for measuring propagation velocities of RF pulses to determine material liquid contents, moisture profiles, material levels and dielectric constants including: i) TDR probes and/or probe adaptors, including series averaging probes and multi-segment probes, all employing remotely operable, normally open, variable impedance devices such as diodes; ii) bias insertion and switching networks for rendering selected normally open variable impedance devices conductive one at a time to establish precise unambiguous timing markers T.sub.1 . . . T.sub.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: March 10, 1998
    Assignee: Precision Moisture Instruments, Inc.
    Inventor: William R. Hook
  • Patent number: 5619143
    Abstract: A method and apparatus for detecting grain direction in wood by means of microwave radiation. A sample of timber is exposed to a polarized microwave beam emitted by a transmitter (11). A polarized receiver (12) evaluates the microwave energy that has been affected by the timber. The receiver and transmitter polarization planes are locked at either 0 or 90 degrees respect to each other. Both are rotated synchronously and the received energy is plotted versus angle. The energy maximum or minimum gives indication of the grain direction in the timber sample under evaluation.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: April 8, 1997
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventors: Thomas J. Stevens, Robert H. Leicester
  • Patent number: 5602484
    Abstract: A multipath component detector detects the correlation between a received signal and a reference signal in a training period of the received signal and estimates and outputs the multipath received component levels at a plurality of timing points. A component ratio calculator calculates the ratio of each received component to the overall received power. By this, the level ratio of a specified received component can be detected. Power dissipation can be minimized by switching the detector to a differential detector or an adaptive equalizer in accordance with the result of the delay spread measurement.
    Type: Grant
    Filed: January 18, 1995
    Date of Patent: February 11, 1997
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Hiroshi Suzuki, Kazuhiko Fukawa
  • Patent number: 5559441
    Abstract: A flexible and efficient integrated circuit chip that includes pad drivers for driving an impedance of a transmission line, wherein the integrated circuit further includes all additional circuitry to automatically adjust a matching impedance of the pad drivers. The integrated circuit chip includes a set of selectively activatable pad drivers and a counter coupled with the drivers for selectively activating an initial number of members of the set of the pad drivers to drive the transmission line with a test pulse. The integrated circuit chip further includes a comparator having a first input for sensing a voltage amplitude of the test pulse and a second input coupled with a voltage reference for comparing the voltage amplitude of the test pulse with the reference voltage. An output of the comparator is coupled with the counter for increasing the counter's initial number of selected members of the set of the pad drivers if the voltage amplitude of the test pulse is less than the reference voltage.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: September 24, 1996
    Assignee: Hewlett-Packard Company
    Inventor: Alan R. Desroches
  • Patent number: 5546007
    Abstract: Apparatus which determines the water cut of a sample petroleum stream irradiates the sample stream at two different locations with microwave energy. The distance that the microwave energies pass through the sample stream are also different. A receiver receives the microwave energies and provides corresponding received signals. The water cut is determined in accordance with the received signals.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: August 13, 1996
    Assignee: Texaco Inc.
    Inventor: John D. Marrelli
  • Patent number: 5543721
    Abstract: For extending the dynamic range in measurements carried out with a directional coupler, such as antenna measurements, a signal is supplied to the object under analysis, such as an antenna, through a first port of the measuring directional coupler, part of the signal leaking as a leak signal through a second port of the measuring directional coupler directly towards a measuring device. The signal returning from the object under analysis is measured by the measuring device. To enable the measuring of signal levels lower than before, spurious signals, such as the leak signal, summing to the signal to be measured are eliminated by supplying a phased compensation signal through a second directional coupler to the measuring line.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: August 6, 1996
    Assignee: Nokia Telecommunications OY
    Inventor: Mika Knuuti
  • Patent number: 5502392
    Abstract: A method for completely characterizing coupled transmission lines by short-pulse propagation is described. The complex frequency-dependent propagation matrix, impedance matrix and admittance matrix for a set of n parallel transmission lines can be determined by comparing the properties of two sets of coupled transmission lines of different length. Each transmission line set has two conductors of unequal length and ground conductors to form a coupled transmission line system. Each transmission line set can have uncoupled ends. An input pulse is provided at at least one node of each transmission line set. The complex frequency dependent propagation matrix of each transmission line set is determined by a comparison of the output pulses at the remaining nodes of each transmission line set which involves ratioing to cancel out the effect of the pad-to-probe discontinuity and the uncoupled ends which make it unnecessary to do any embedding.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: March 26, 1996
    Assignee: International Business Machines Corporation
    Inventors: Gnanalingam Arjavalingam, Alina Deutsch, Gerard V. Kopcsay, James K. Tam
  • Patent number: 5500599
    Abstract: An apparatus and a method for the measurement of the complex dielectric constant of a material by evaluating the amount of detuning introduced by the presence of the material. In order to simplify the circuitry required for measurement and evaluation according to the invention there are provided two rf resonators (8, 8') of the same construction, each of them comprising a dielectric solid state resonator (1, 1') in a case having a first conductive section (2, 2') and a second section (3, 3'), which is permeable for alternating fields. Both the rf resonators are positioned to each other in such a way as to provide a shielding effect by their conductive case sections (2, 2') against mutual interference and to have their sections permeable for electromagnetic fields (3, 3') facing towards the material to be measured.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: March 19, 1996
    Assignee: Nu-Tech GmbH
    Inventor: Gerd Stange
  • Patent number: 5497100
    Abstract: A surface condition sensing system includes a frequency controlled source of electromagnetic power adapted to produce a band of selected frequencies which are directed to a surface under examination. A monitoring circuit compares transmitted and reflected electromagnetic power as a function of frequency from the surface, and generates a plurality of absorption signals representing the difference between the amplitude of the transmitted signal with the corresponding amplitude of the reflected signal. An evaluator circuit generates a surface condition signal representing the results of a comparison between the plurality of absorption signals with known surface models. A control circuit generates a status signal representative of the surface condition. The system can be configured as a road condition sensor or as an aircraft ice detection sensor.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: March 5, 1996
    Assignee: Hughes Aircraft Company
    Inventors: Kurt Reiser, Scott Y. Harmon, Jennifer M. Butler
  • Patent number: 5497098
    Abstract: A sensor and method for identifying the surface properties of a workpiece includes a microstrip sensor for transmitting and receiving microwave signals and surface properties determining means for determining the surface properties of the workpiece, including the type of material from which the workpiece is constructed, based upon the strength of the detected microwave signals. The surface properties identifying sensor also includes a microwave generator for producing microwave signals at a predetermined frequency for transmission by the microstrip sensor and a detector for detecting the microwave signals received by the microstrip sensor from the workpiece. Thus, workpieces comprised of a conductive material, an insulative material and a conductive material coated with a radar absorbing material can be readily distinguished by the surface properties identifying sensor and method.
    Type: Grant
    Filed: November 10, 1994
    Date of Patent: March 5, 1996
    Assignee: McDonnell Douglas Corporation
    Inventors: Garret G. Heil, John J. Domalewski, Frederick C. Wear, Stephen C. Buckner, Arthur C. Lind, Jeffry K. Hoyt
  • Patent number: 5376888
    Abstract: Time Domain Reflectometry ("TDR") methods and apparatus for measuring propagation velocities of RF pulses to determine material liquid contents, moisture profiles, material levels and dielectric constants including: i) TDR probes and/or probe adaptors, including series averaging probes and multi-segment probes, all employing remotely operable, normally open, variable impedance devices such as diodes; ii) bias insertion and switching networks for rendering selected normally open variable impedance devices conductive one at a time to establish precise unambiguous timing markers T.sub.1 . . . T.sub.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: December 27, 1994
    Inventor: William R. Hook
  • Patent number: 5373244
    Abstract: The means and method of the present invention includes a source of microwave energy and associated elements which provide microwave energy to a petroleum stream. Other circuitry include elements which receive microwave energy from the petroleum stream. Electronic apparatus provides at least one outputs utilizing the provided microwave energy, the received microwave energy and known values for 100 percent oil, percent surfactant and 100 percent water, corresponding to a ratio of surfactant to oil/water mixture.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: December 13, 1994
    Assignee: Texaco Inc.
    Inventor: John D. Marrelli
  • Patent number: 5369369
    Abstract: An apparatus and method to measure the unburnt carbon content of fly ash. A microwave signal is transmitted through or reflected from a fly ash sample and the attenuation or phase shift of the signal received by a detector/detectors is determined with respect to the incident signal and is used to provide a measure of unburnt carbon content. The detectors may be antennae means which also launch the incident signal or may be a completely separate means. A preferred embodiment comprises a microwave oscillator for launching the microwave signal into a fly ash sample in a microwave resonant cavity. Detectors determine the attenuation of phase shift of the received signal with respect to a signal from a reference microwave resonant cavity by the fly ash sample, and a measurement of the unburnt carbon content is obtained.
    Type: Grant
    Filed: September 14, 1992
    Date of Patent: November 29, 1994
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventor: Nicholas G. Cutmore
  • Patent number: 5245291
    Abstract: Method and apparatus for detecting a length of a cable connecting information equipments are disclosed. A reference signal which is a repetitively occurring signal is transmitted through a cable. A phase difference between the reference signal transmitted through the cable and the reference signal directly transmitted without routing the cable is detected, and a signal representing the cable length is produced based on the detected phase difference.
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: September 14, 1993
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Nobuaki Fujimura
  • Patent number: 5229726
    Abstract: A portable device for use in the measurement of the dielectric properties of materials such as fish includes: a microwave circuit comprising a microwave source (10) connected via an isolator (12) to a directional coupler (14), a first output (16) of which is connected to a reference detector (18) and a first pre-amplifier (28) and a second output (20) of which is connected via an attenuator (22) to a sensor (24), an output of which is connected to a signal detector (26) and a second pre-amplifier (30); and further including two amplifiers (32, 34) into which outputs of the first (28) and second (30) pre-amplifiers are connected and a logarithmic/ratio device (38) which provides an output proportional to the logarithm of the ratio of outputs from the two amplifiers (32, 34), wherein an output from the logarithmic/ratio device (38) is calibrated to provide the content of a particular constituent of the material under test.
    Type: Grant
    Filed: January 3, 1992
    Date of Patent: July 20, 1993
    Assignee: The Secretary of State for Minister of Agriculture Fisheries and Food In Her Britannic Majesty's Government of the united Kingdom of Great Britain and Northern Ireland
    Inventor: Michael Kent
  • Patent number: 5159275
    Abstract: Method and apparatus for detecting a length of a cable connecting information equipments are disclosed. A reference signal which is a repetitively occurring signal is transmitted through a cable. A phase difference between the reference signal transmitted through the cable and the reference signal directly transmitted without routing the cable is detected, and a signal representing the cable length is produced based on the detected phase difference.
    Type: Grant
    Filed: December 4, 1990
    Date of Patent: October 27, 1992
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Nobuaki Fujimura
  • Patent number: 5101163
    Abstract: A device for measuring the concentration of two substances through the transmission of electromagnetic waves. The device utilizes at least one transmission element for transmitting a signal and at least two receiving elements for receiving a signal from the at least one transmission element and providing first and second output signals. The present invention also utilizes a receiving device for receiving the first and second output signals from the at least two receiving elements such that the difference or ratio of the two signals is utilized to determine the concentration.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: March 31, 1992
    Assignee: Agar Corporation Ltd.
    Inventor: Joram Agar
  • Patent number: 5086279
    Abstract: A hygroscopic commodity, such as a continuous stream of shredded tobacco, is transported past one or more sources of electrical energy and past one or more monitoring devices. One of the sources can expose the stream to the electric field of a capacitor in a high frequency oscillator circuit, and the other source can expose the stream to infrared waves or microwaves. The moisture in the stream influences the phase and/or the damping of oscillations of the electrical energy, and the monitoring device of devices ascertain the changes of such characteristics of the electrical energy and transmit corresponding signals to a processing circuit which processes the signals into moisture signals.
    Type: Grant
    Filed: February 23, 1990
    Date of Patent: February 4, 1992
    Assignee: Korber AG
    Inventors: Waldemar Wochnowski, Heiko Niehues