Selective Type Characteristics Patents (Class 324/619)
  • Patent number: 11448673
    Abstract: A device having an impedance measurement circuit that allows for reduction of flicker noise can be implemented in a variety of applications. A carrier suppression technique can be implemented that substantially removes the carrier signal with removal of noise artifacts associated with the carrier signal from sidebands of the carrier signal. Carrier suppression in an AC impedance measurement circuit can be implemented by sensing a carrier signal of the measurement circuit at a transmit location of the measurement circuit and subtracting a weighted version of the carrier signal at a receive location of the measurement circuit. One or more compensation impedances can be used such that the sidebands of the carrier signal are received with the carrier signal suppressed with respect to the receive location.
    Type: Grant
    Filed: November 3, 2020
    Date of Patent: September 20, 2022
    Assignee: Analog Devices International Unlimited Company
    Inventors: Colin G. Lyden, Thomas J. Tansley, Oliver J. Brennan
  • Patent number: 10418994
    Abstract: A circuit for extending the bandwidth of a termination block is described. The circuit comprises an I/O contact configured to receive an input signal; and a termination circuit coupled to the I/O contact, wherein the termination circuit comprises a plurality of trim legs coupled between a power supply and the I/O contact, each trim leg having a switch to control the impedance in the trim leg.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: September 17, 2019
    Assignee: Xilinx, Inc.
    Inventors: Edward Cullen, Ionut C. Cical
  • Patent number: 9755671
    Abstract: Embodiments of radio frequency (RF) filter front-end circuitry are disclosed that include a tunable RF filter structure having weakly coupled resonators and a Voltage Standing Wave Ratio (VSWR) control circuit. The VSWR control circuit is configured to detect a VSWR at a terminal of the tunable RF filter structure and to dynamically tune the tunable RF filter structure based on the VSWR. In this manner, the VSWR control circuit tunes the tunable RF filter structure to improve performance of tunable RF filter structure over variations in the VSWR.
    Type: Grant
    Filed: August 1, 2014
    Date of Patent: September 5, 2017
    Assignee: Qorvo US, Inc.
    Inventors: George Maxim, Dirk Robert Walter Leipold, Baker Scott
  • Patent number: 9722577
    Abstract: A system that incorporates teachings of the present disclosure may include, for example, an adaptive impedance matching network having an RF matching network coupled to at least one RF input port and at least one RF output port and comprising one or more controllable variable reactive elements. The RF matching network can be adapted to reduce a level of reflected power transferred from said at least one input port by varying signals applied to said controllable variable reactive elements. The one or more controllable variable reactive elements can be coupled to a circuit adapted to map one or more control signals that are output from a controller to a signal range that is compatible with said one or more controllable variable reactive elements. Additional embodiments are disclosed.
    Type: Grant
    Filed: August 3, 2015
    Date of Patent: August 1, 2017
    Assignee: BlackBerry Limited
    Inventor: William E. McKinzie, III
  • Patent number: 9331723
    Abstract: Devices and methods are disclosed for real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a receiver. Processing logic is operable to solve multiple non-linear equations to determine the reflection coefficient of the antenna. The tunable matching network is repeatedly perturbed and the power received by the antenna is measured after each perturbation at the same node in the matching network. The measured power values are used by an optimizer in converging to a solution that provides the reflection coefficient of the antenna. The reflection coefficient of the antenna may be used to determine the input impedance of the antenna. The elements of the matching circuit may then be adjusted to match the input impedance of the antenna.
    Type: Grant
    Filed: November 14, 2011
    Date of Patent: May 3, 2016
    Assignee: BlackBerry Limited
    Inventors: Shirook M. Ali, Michael Eoin Buckley, James P. Warden, John B. Deforge
  • Publication number: 20140239978
    Abstract: A device can include a radio frequency (RF) signal input, a local oscillator (LO) signal input, a mixer to receive the RF signal and LO signal and translate a frequency of the RF signal based on the LO signal, a strobe pulsing component to provide a timed strobe pulse, and a second mixer to receive a leakage signal, LO signal, and timed strobe pulse, and also to translate a frequency of the leakage signal to baseband. The device can also include a coupling component configured to allow the leakage signal to pass between the mixers. An output signal output can provide a measured value of the leakage signal.
    Type: Application
    Filed: February 22, 2013
    Publication date: August 28, 2014
    Applicant: Tektronix, Inc.
    Inventors: Donald J. Delzer, Gordon Alan Olsen
  • Patent number: 8779777
    Abstract: A current sense resistor circuit may include a primary current sense resistor that drifts with age. A secondary current sense resistor may drift with age in substantial unison with the primary current sense resistor. A calibration resistor may not drift with age in substantial unison with the primary current sense resistor. A compensation circuit may compensate for aging drift in the resistance of the primary current sense resistor based on a comparison of the calibration resistor with the secondary current sense resistor. The secondary current sense resistor may be in parallel with the primary current sense resistor, except when the compensation circuit is comparing the calibration resistor with the secondary current sense resistor.
    Type: Grant
    Filed: May 19, 2011
    Date of Patent: July 15, 2014
    Assignee: Linear Technology Corporation
    Inventors: Frank Irmer, Bernhard Engl
  • Publication number: 20130257454
    Abstract: A wireless electronic device may contain an antenna tuning element for tuning the device's operating frequency range. The antenna tuning element may include radio-frequency switches, continuously/semi-continuously adjustable components such as tunable resistors, inductors, and capacitors, etc. A test system may be used to measure the radio-frequency characteristics associated with the tuning element assembled with an electronic device. The test system may include a test host, a test chamber, a signal generator, power meters, and radio-frequency testers. The electronic device under test (DUT) may be placed in the test chamber. The signal generator may generate radio-frequency test signals for energizing the antenna tuning element. The power meters and radio-frequency testers may be used to measure conducted and radiated signals emitted from the DUT while the DUT is placed in different desired orientations. A phantom object is optionally placed in the vicinity of the DUT to simulate actual user scenario.
    Type: Application
    Filed: April 2, 2012
    Publication date: October 3, 2013
    Inventors: Matthew A. Mow, Rocco V. Dragone, JR., Thomas E. Biedka, Robert W. Schlub, Ruben Caballero
  • Patent number: 8508217
    Abstract: An output circuit of a charge mode sensor includes a second resistor and an operational amplifier. The second resistor connects an output portion of the charge mode sensor and a ground. The operational amplifier is configured to output a detection signal that varies in accordance with an amount of charge kept in the charge mode sensor. The operational amplifier includes an inverting input portion, a non-inverting input portion, and an output portion. The inverting input portion is connected to the output portion of the charge mode sensor via a sensor cable. The non-inverting input portion is connected to a reference voltage. The output portion is connected to the inverting input portion via a first resistor.
    Type: Grant
    Filed: December 6, 2010
    Date of Patent: August 13, 2013
    Assignee: Honda Motor Co., Ltd.
    Inventor: Yoshimasa Eguchi
  • Publication number: 20120235688
    Abstract: An apparatus for detecting a partial discharge (PD) signal capable of detecting a PD signal of a power device includes: a partial discharge (PD) coupler connected to a ground side of a power device and configured to cancel a low frequency noise component including a commercial frequency from an AC component flowing through the ground side of the power device when a partial PD signal is generated from the power device, and to allow a high frequency component including a PD signal included in the AC component to pass therethrough to generate a PD analog signal; and a PD detection unit configured to cancel a noise signal from the PD analog signal generated by the PD coupler to detect only the PD signal.
    Type: Application
    Filed: March 14, 2012
    Publication date: September 20, 2012
    Applicant: LSIS CO., LTD.
    Inventor: Do Hoon LEE
  • Patent number: 7248059
    Abstract: Embodiments of the present disclosure relate to methods, sensors, and systems for low power sensing. One method for low power sensing includes receiving a detection signal from a detector of a sensor to a delay flip flop (DFF). The method includes switching a DFF output state in response to a switching of the detection signal, when the DFF is reset, transmitting an event report signal from the DFF to a processor of the sensor when the DFF output state switches, and maintaining the DFF output in a steady state, when the DFF is not reset.
    Type: Grant
    Filed: February 24, 2006
    Date of Patent: July 24, 2007
    Assignee: Red Wing Technologies, Inc.
    Inventor: Jomar G. Ochoco
  • Patent number: 7064557
    Abstract: A calibration circuit and method causes a cutoff frequency to match the design frequency of low pass filter by adjusting a capacitor array in the low pass filter.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: June 20, 2006
    Assignee: Broadcom Corporation
    Inventors: Meng-An Pan, Stephen Wu
  • Patent number: 6518774
    Abstract: Electrical filter circuits are tested by connecting test apparatus to the filter circuit inputs, without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter circuit inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter circuits have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results by a computer to determine characteristics of the filter circuit, such as values of the individual sub-components of the filter circuit. An interactive process is applied to successively improve the accuracy of the component value determinations over a range of frequencies. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Grant
    Filed: January 15, 2002
    Date of Patent: February 11, 2003
    Assignee: BCF Designs Limited
    Inventor: Anthony James Moore
  • Publication number: 20020084788
    Abstract: Electrical filter circuits are tested by connecting test apparatus to the filter circuit inputs, without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter circuit inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter circuits have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results by a computer to determine characteristics of the filter circuit, such as values of the individual sub-components of the filter circuit. An interactive process is applied to successively improve the accuracy of the component value determinations over a range of frequencies. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Application
    Filed: January 15, 2002
    Publication date: July 4, 2002
    Applicant: BCF Designs Limited
    Inventor: Anthony James Moore
  • Patent number: 6411101
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filters have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a computer to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is an L-section filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: June 25, 2002
    Assignee: BCF Designs Limited
    Inventor: Anthony James Moore
  • Publication number: 20020024343
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a compute to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is an L-C filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Application
    Filed: September 12, 2001
    Publication date: February 28, 2002
    Applicant: BCF Designs Limited
    Inventor: Anthony James Moore
  • Patent number: 6331779
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a compute to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is an T-section low pass filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: December 18, 2001
    Assignee: BCF Designs Limited
    Inventor: Anthony James Moore
  • Patent number: 6326793
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a compute to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is an L-C filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: December 4, 2001
    Assignee: BCF Designs Limited
    Inventor: Anthony James Moore
  • Publication number: 20010007426
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a compute to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is an L-C filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Application
    Filed: February 16, 2001
    Publication date: July 12, 2001
    Applicant: BCF Designs Limited
    Inventor: Anthony James Moore
  • Patent number: 6252411
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a compute to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is C-section low pass filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: June 26, 2001
    Assignee: BCF Designs Limited
    Inventor: Anthony James Moore
  • Patent number: 6127829
    Abstract: A method and apparatus for determining the center frequency of a bandpass filter. The center frequency of a bandpass filter is determined by applying a bias voltage to a bandpass filter circuit receiving a pair of differential input voltages and producing a pair of differential output voltages. The differential output voltages are modified to exhibit a notchband magnitude characteristic. A minimum value of the differential output voltages exhibiting the notchband characteristic over a predetermined range of frequencies is determined and corresponds to the center frequency of the bandpass filter.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: October 3, 2000
    Assignee: Texas Instruments Incorporated
    Inventor: Mehmet Ali Tan
  • Patent number: 6121778
    Abstract: Electrical filter circuits are tested by connecting to the filter inputs without the need to connect to the filter outputs or to disconnect the outputs from a load. A signal generator of known source resistance applies a.c. signals successively over a range of frequencies to the filter inputs, and a voltmeter monitors the voltage across the filter inputs. Different types of filter have different characteristic shapes for the voltage/frequency curve, and processing is applied to the measured results in a compute to determine the location of inflections in the curve and other characteristics of the curve. Methods are disclosed for determining the values of the individual sub-components of the filter. Where the filter is an L-C filter, an interactive process is applied to successively improve the accuracy of the component value determinations. Using the techniques described enables the insertion loss of the filter also to be readily calculated by the computer.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: September 19, 2000
    Assignee: BCF Designs Limited
    Inventor: Anthony James Moore
  • Patent number: 6114859
    Abstract: Single-phase currents at two frequencies f.alpha. and f.beta. (f.alpha.<n.multidot.fs<f.beta.) of non-integral multiples of a system fundamental wave frequency fs sandwiching an targeted harmonic (frequency n.multidot.fs) are injected between two phases of a three-phase power system as interharmonic currents. A frequency analysis of measurement current and measurement voltage of each phase in the system is carried out and a positive-phase-sequence current I1, a positive-phase-sequence voltage V1, a negative-phase-sequence current I2, and a negative-phase-sequence voltage V2 are detected for each of the two frequencies f.alpha. and f.beta. in the system based on injecting of the interharmonic currents. Positive-phase-sequence and negative-phase-sequence admittances Y1 and Y2 or positive-phase-sequence and negative-phase-sequence impedances Z1 and Z2 are found for each of the frequencies f.alpha. and f.beta. in the system as Y1=I1/V1 and Y2=I2/V2 or Z1=V1/I1 and Z2=V2/I2.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: September 5, 2000
    Assignees: Nissin Electric Co., Ltd., Chuba Electric Power Co., Inc.
    Inventors: Isao Koda, Masakazu Tsukamoto, Yasuhiro Fuwa, Shoji Nishimura, Yoshifumi Minowa, Yasuyuki Natsuda
  • Patent number: 6046594
    Abstract: A method and apparatus for measuring electrical characteristics (e.g. current, voltage, phase, etc.) between a power source and a load at a set of harmonic frequencies to determine information about the load (e.g., load impedance, power dissipation, etc). According to one aspect of the invention, a first circuit detects a set of electrical characteristics (e.g., current, voltage, and/or phase) of a signal between the power source and the load. A second circuit, coupled to the first circuit to receive the set of electrical characteristics, provides data representing the set of electrical characteristics at a harmonic frequency associated with the signal. A third circuit, coupled to the second circuit, receives the data and determines information about the load (e.g., impedance, power dissipation, discharge current, etc.) at the harmonic frequency.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: April 4, 2000
    Assignee: Advanced Energy Voorhees, Inc.
    Inventor: Anton Mavretic
  • Patent number: 6008642
    Abstract: A stochastic resonator signal detector comprises a multi-stable nonlinear device for coupling to an input signal and a control signal coupled to the multi-stable nonlinear device for varying asymmetry among stable states of the multi-stable nonlinear device. The interaction of the input signal with the control signal in the multi-stable nonlinear device generates an output signal having an amplitude responsive to the input signal amplitude and a frequency range that comprises harmonics of products of the control signal and the input signal.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: December 28, 1999
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Adi R. Bulsara, Mario E. Inchiosa, Luca Gammaitoni, Frank E. Gordon
  • Patent number: 5712573
    Abstract: In a network analyzer for the measurement of frequency-dependent measurement parameters of an object undergoing measurement, the waiting period at which the locked oscillator is switchable between the successive frequency measurement points is controlled in dependence on the comparison of at least two immediately successive measurement results at the same measurement point.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: January 27, 1998
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventor: Werner Held
  • Patent number: 5475315
    Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.
    Type: Grant
    Filed: July 23, 1993
    Date of Patent: December 12, 1995
    Assignee: Audio Precision, Inc.
    Inventor: Richard C. Cabot
  • Patent number: 5463317
    Abstract: An apparatus which can non-intrusively verify the integrity of shielding on electrical wiring. The method utilizes the natural resonance of the voltage transfer function of the shielded wire. The frequency of this resonance is an indication of the self inductance of the cable. A change in the resonant frequency indicates a change in the self inductance caused by a failure in the shield circuit.
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: October 31, 1995
    Assignee: The Boeing Company
    Inventor: Timothy A. Murphy
  • Patent number: 5404109
    Abstract: A test system for measuring the characteristics of an active circuit employs a pulsed bias technique for periodically biasing the input control port of the active circuit into the active region of operation. Biasing is achieved with a bias voltage that is periodically pulsed ON and OFF. An RF source is pulse modulated ON and OFF synchronously with the pulsed bias voltage and applied to the input control port of the active circuit. The pulsed RF occupies a portion of the time interval encompassed by the pulsed bias voltage. These voltages are combined and applied to the input port of the active circuit which operates only during the presence of the pulsed bias voltage and which is OFF during the absence of the pulsed bias voltage. A DC supply is utilized to bias the output port. The amplified RF power is then measured at the output port of the circuit, after the RF power has been separated from the DC bias by a non-reciprocal device.
    Type: Grant
    Filed: December 13, 1993
    Date of Patent: April 4, 1995
    Assignee: ITT Corporation
    Inventors: William L. Pribble, Michael D. Pollman, Roger D. Sweeney
  • Patent number: 5210483
    Abstract: A measuring unit converts a measuring signal into an intermediate frequency band of a predetermined bandwidth and detects the intermediate frequency band while a reception frequency is set variable by variably controlling a local oscillation frequency of a local oscillator. A waveform memory stores the magnitude of a detection signal output from the measuring unit in correspondence with the frequency. An analyzing unit analyzes a frequency component included in a signal to be measured, on the basis of a storage value of the waveform memory. An analysis target frequency data setting unit sets frequency data of a desired analysis target frequency or interval frequency data thereof.
    Type: Grant
    Filed: September 26, 1991
    Date of Patent: May 11, 1993
    Assignee: Anritsu Corporation
    Inventors: Narushi Amamoto, Hiroyoshi Oka, Takehiko Sato, Aiichi Katayama
  • Patent number: 5132630
    Abstract: In an analyzer for measuring the frequency characteristics of quadripoles, comprising an indicator circuit in which the output of the quadripole to be measured is converted to an intermediate frequency by a mixer and a frequency-variable local oscillator, and comprising a variable-frequency second local oscillator whose output frequency is mixed with another mixer and with the frequency of the local oscillator to be converted to an input signal for the quadripole to be measured, the output frequency of the variable frequency second local oscillator is adjusted to be offset by at least .+-.5 MHz relative to the intermediate frequency value of the indicator circuit.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: July 21, 1992
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventor: Klaus Danzeisen
  • Patent number: 5099200
    Abstract: To determine the phase and amplitude response of a superheterodyne instrument, a fixed frequency signal is applied to the instrument's signal input port. The superheterodyne local oscillator is then swept to translate the fixed frequency input signal into a sweeping sinusoid that traverses the I.F. passband. Data is acquired as the signal sweeps the passband and is analyzed to determine the phase and amplitude characteristics of the instrument. These characteristics are logged in a memory and are used to remove artifacts of instrument-induced frequency response errors from subsequent measurements.
    Type: Grant
    Filed: January 12, 1990
    Date of Patent: March 24, 1992
    Assignee: Hewlett-Packard Company
    Inventors: Joseph F. Tarantino, Eric J. Wicklund, Jerry W. Daniels
  • Patent number: 5059915
    Abstract: A vector network analyzer comprising a circuit for measuring the real and imaginary components of the central spectral line in an RF pulse from a device-under-test is provided. The circuit comprises a modulator in response to a profiling pulse for modulating the amplitude of the RF pulse, mixers for down-converting the frequency of the amplitude modulated RF pulse, a narrow band filter for filtering the RF pulse having a bandwidth of 500 Hz and a synchronous detector responsive to the output of the crystal filter for providing a pair of dc outputs, which correspond to the real and imaginary components of the output of the device under test as the profiling pulse is shifted in time relative to the RF pulse.
    Type: Grant
    Filed: December 1, 1989
    Date of Patent: October 22, 1991
    Assignee: Wiltron Company
    Inventors: Martin I. Grace, Peter M. Kapetanic