Digital Filter Patents (Class 324/76.28)
  • Patent number: 10622891
    Abstract: A method for controlling a load-current zero-crossing of a switching regulator having a high-side switch and a low-side switch includes detecting, by a spike detection circuit, a presence of a spike on an output voltage of the switching regulator, determining, by the spike detection circuit, in the event that a spike is present, whether the spike is a positive spike or a negative spike, and adjusting a turn-off timing of the low-side switch based on a determination result.
    Type: Grant
    Filed: May 6, 2019
    Date of Patent: April 14, 2020
    Assignee: SHENZHEN GOODIX TECHNOLOGY CO., LTD.
    Inventors: Siavash Yazdi, Faisal Hussien
  • Patent number: 9517562
    Abstract: A robot controller includes a force control unit that outputs a correction value of a target track of a robot based on a detected sensor value acquired from a force sensor, a target value output unit that obtains a target value by performing correction processing on the target track based on the correction value and outputs the obtained target value, and a robot control unit that performs feedback control of the robot based on the target value. The force control unit includes an impedance processor that obtains a solution of a differential equation in force control as the correction value before the conversion processing, and a nonlinear convertor that obtains the correction value after the conversion processing by performing nonlinear conversion processing on the correction value before the conversion processing acquired from the impedance processor and outputs the obtained correction value after the conversion processing.
    Type: Grant
    Filed: March 30, 2015
    Date of Patent: December 13, 2016
    Assignee: Seiko Epson Corporation
    Inventor: Mitsuhiro Inazumi
  • Patent number: 9450629
    Abstract: A method for controlling local oscillator (LO) feed-through in a direct transmitter includes detecting a signal level corresponding to LO feed-through in a radio frequency (RF) signal that is output by a direct transmitter. Responsive to detecting the signal level corresponding to LO feed-through, DC offset levels are modified for an in-phase (I) signal and/or a quadrature-phase (Q) signal in the direct transmitter.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: September 20, 2016
    Assignee: Skyworks Solutions, Inc.
    Inventor: Mark M. Cloutier
  • Patent number: 8760147
    Abstract: The current invention relates, inter alia, to charge pulse amplitude and time detecting circuits, offering very low amplitude and temporal noise, and overcoming noise performance limits in charge pulse detection circuits according to prior art. Embodiments of the present invention may include a sensing device delivering charge pulses onto a sense node, an active buffer buffering the voltage on the sense node with a low impedance, a recharge device removing signal charge from the sense node, a noise filter connected to the output of the active buffer transmitting signal voltage pulses while attenuating noise from the recharge device. Additional and alternative embodiments are specified and claimed.
    Type: Grant
    Filed: November 11, 2009
    Date of Patent: June 24, 2014
    Assignee: CSEM Centre Suisse d'Electronique et de Microtechnique SA—Recherche et Developpement
    Inventors: Christian Lotto, Peter Seitz
  • Patent number: 8428114
    Abstract: Transmit equalization over high speed digital communication paths may be compensated in a receiver for a probe on that path. In one example, a probe input provides a signal from an electronic communications path, the signal having been processed by a transmit equalizer. A filter circuit processes the signal to compensate for the transmit equalizer, and a decoder decodes the processed signal and produces an output for use by test equipment.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: April 23, 2013
    Assignee: Intel Corporation
    Inventors: Larry R. Tate, Harry R. Rogers
  • Patent number: 8295412
    Abstract: An apparatus and method for signal detection in which a digital sample stream is fed round robin into a plurality of buffers, which are sequentially compared with a reference signal to determine a match. A processor determines the chronological order of the samples in each bit of each buffer, and directs a bitwise comparison between the signal in each buffer with the reference to determine a match, e.g., by correlation. The apparatus and method are preferably implemented with a Field-Programmable Gate Array (FPGA). This scheme permits real time correlation of a data stream with a reference without use of shift registers, or a significant number of dedicated logic blocks.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: October 23, 2012
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Jeremy R. O'Neal
  • Patent number: 8175185
    Abstract: A radio frequency (RF) transmitter includes a transmitter processing module that generates a processed signal and a modulating signal based on outbound data. An up-conversion module up-converts the processed signal to generate an up-converted signal. A programmable filter module generates a first plurality of delayed signals from the up-converted signal and that generates a filtered up-converted signal by combining the up-converted signal and the first plurality of delayed signals, wherein a delayed signal of the first plurality of delayed signals is scaled based on one of a first plurality of coefficients, wherein the first plurality of coefficients are selected based on a control signal. A polar amplifier amplifies and amplitude modulates the filtered up-converted signal based on the modulating signal to generate a transmit signal. A processing module generates the control signal to attenuate at least one RF spur of the up-converted signal.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: May 8, 2012
    Assignee: Broadcom Corporation
    Inventor: Ahmadreza (Reza) Rofougaran
  • Patent number: 7783456
    Abstract: It is possible to detect a reception signal at a high speed. A wave detection device includes: a first signal output unit for outputting a first signal s[n] which is a sum of a digital input signal subjected to A/D conversion and an output from a feedback signal output section; a second signal output unit for outputting a second signal s[n?1] which is the first signal s[n] delayed by one sampling timing; and a feedback signal output section for subjecting the second signal s[n?1] to a predetermined calculation. When n=N?1, a frequency region conversion section reads out the first signal s[N?1] and the second signal s[N?2] from registers and subjects them to a predetermined calculation, thereby obtaining the input signal subjected to DFT. Since the wave detection device has a simple configuration, it is possible to rapidly detect the reception signal which is an input signal of the wave detection device.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: August 24, 2010
    Assignee: Advantest Corporation
    Inventor: Satoshi Takahashi
  • Patent number: 7746052
    Abstract: A spectrum analyzer is provided with frequency-scalable circuit architectures that extend the bandwidth of the spectrum analyzer using an array of couplers. The array of couplers is distributed along the RF signal path at one end, and interfaced to one or more frequency-translation devices such as mixers or samplers at the other. In a first architecture, a single mixer is employed with an LO signal applied to one input and coupler outputs providing RF signals to another input, with switching controlled to select one coupler's RF output to provide to the mixer. In a second architecture, a separate mixer is used, one for each coupler RF signal, with switches selecting one of the mixer IF outputs to select a desired output frequency. Both the first and second embodiments eliminate switching and its associated loss and frequency limitations from the main RF signal path to enable wideband high-dynamic-range spectrum analysis.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: June 29, 2010
    Assignee: Anritsu Company
    Inventor: Karam Michael Noujeim
  • Patent number: 7746057
    Abstract: A power meter having complex quadrature output current and voltage filters provides power measurements in high amplitude and frequency variation and/or high jitter environments without requiring high computational overhead. A pair of filters, one for voltage and one for current each have a response determined by complex non-conjugate poles. The response of the filters is such that only the positive or negative half plane of the complex frequency spectrum is passed and provide complex outputs representing the real and imaginary parts of both the current and voltage. At least one indication of a power delivered to a load is computed from the complex current and voltage outputs, which may be the real and/or reactive power.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: June 29, 2010
    Assignee: Cirrus Logic, Inc.
    Inventor: John L. Melanson
  • Patent number: 7742893
    Abstract: A calibration circuit calibrates an adjustable capacitance of a circuit having a time constant depending on the adjustable capacitance. The calibration circuit outputs a calibration signal carrying information for calibrating the capacitor and includes a calibration loop.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: June 22, 2010
    Assignee: STMicroelectronics S.r.l.
    Inventors: Pierangelo Confalonieri, Riccardo Martignone, Marco Zamprogno
  • Patent number: 7460967
    Abstract: Events discovered by an automatic measurement subsystem in the trace of a DSO are visited using a set of event navigation controls. In a TIME Mode the controls operate to display the first of those events, display the next event after the one currently displayed, display the previous event before the one currently displayed, and, display the last event. In a SEVERITY Mode the controls operate to display the best of those events, display the next best event relative to the one currently displayed, display the next worst event before the one currently displayed, and, display the worst event. The sets of navigation controls may be a mode control menu accompanied by four stylized arrow shaped buttons within a GUI that are clicked on by an operator using a mouse. One set of arrow shaped button can serve both modes, or different sets of buttons can serve each respective mode.
    Type: Grant
    Filed: June 28, 2006
    Date of Patent: December 2, 2008
    Assignee: Agilent Technologies, Inc.
    Inventor: Christopher P Duff
  • Patent number: 7171324
    Abstract: A test system and method which utilizes a component data base that stores performance data for individual component of the system. The system and method can further provide for using data and information from one calibration procedure in connection with performing further calibration procedures. The system and method can further provide for utilizing data of from linear components of the system to determine performance characteristics of non-linear components.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: January 30, 2007
    Assignee: Agilent Technologies, Inc.
    Inventors: Daniel L. Pleasant, Gopalakrishnan Kailasam
  • Patent number: 7164261
    Abstract: A resonance-frequency measuring method is used for measuring a resonance frequency of an information recording/reproducing device reproducing information recorded on a medium by driving a mechanism unit. The resonance-frequency measuring method includes the measuring step of applying sine-wave oscillations at different frequencies one by one to the mechanism unit, and counting the number of times information reproduced upon application of each of the sine-wave oscillations differs from information indicating an aimed location, and the resonance-frequency determining step of determining the resonance frequency according to the number of times counted in the measuring step.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: January 16, 2007
    Assignee: Fujitsu Limited
    Inventors: Shuichi Hashimoto, Ryuki Kubohara, Tatsuhiko Kosugi, Takeyori Hara, Yoshiyuki Kagami
  • Patent number: 7155372
    Abstract: In one embodiment, a method that includes creating a filter structure using a parameter of a periodic pulse train, the filter structure having a plurality of time slots, each time slot being associated with a memory value; receiving a pulse at a time; incrementing the memory value associated with the time slot corresponding to the time the pulse was received; filtering the pulse if the memory value exceeds a threshold; and transmitting the pulse to a processor if the memory value does not exceed the threshold. In another embodiment, an apparatus that includes an input filter; a pulse detection circuit coupled to the input filter; a periodic pulse filter coupled to the pulse detection circuit; and a pulse queuing and transmission circuit coupled to the periodic pulse filter.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: December 26, 2006
    Assignee: BAE Systems Information and Electronic Systems
    Inventor: William C. Alexander
  • Patent number: 7136783
    Abstract: Methods and arrangements for processing a signal using a digital processor having a given word length. The signal is pre-processed using a pre-processor which reduces the word length and performs an operation which is invariant with respect to a process being performed by the digital signal processor. This means that if the pre-processor operated with infinite accuracy, it would have no effect on the subsequent process. If such a pre-processor operates with infinite accuracy, it will reduce the guantization noise. In the digital signal processor, the pre-processed signal may be transformed into frequency coefficients which are normalized directly thereafter.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: November 14, 2006
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Johan Paul Marie Gerard Linnartz, Antonius Adrianus Cornelis Maria Kalker, Johan Cornelis Talstra, Antonius Adriaan Maria Staring
  • Patent number: 7117128
    Abstract: A Q-Filter is a reconfigurable technique that performs a continuum of linear and nonlinear filtering operations. It is modeled by unique mathematical structure, utilizing a function called the Q-Measure, defined using a set of adjustable kernel parameters to enable efficient hardware and software implementations of a variety of useful, new and conventional, filtering operations. The Q-Measure is is based on an extension of the well-known Sugeno ?-Measure.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: October 3, 2006
    Assignee: Motorola, Inc.
    Inventors: Magdi A. Mohamed, Weimin Xiao
  • Patent number: 7116093
    Abstract: The tone generator uses a highly accurate frequency signal to generate an accurate and stable tone signal. A cadence pattern may be used to output the tone signal onto a test cable in an easily distinguishable pattern. The tone signal may be selectively output at an in-band band frequency or an out-band frequency. A corresponding tone probe may be used to detect the tone signal. The tone probe uses a high-Q bandpass filter to reject all but the expected frequency of the tone signal. The signal passing the bandpass filter is proportional to the detected tone signal. The tone probe generates an audio signal unrelated to the frequency of the tone signal. The audio signal is modulated by the signal from the bandpass filter, and then broadcast through a speaker. Accordingly, the tone probe provides an audible sound proportional to the strength of the tone signal, but is unrelated in frequency.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: October 3, 2006
    Assignee: Psibor Data Systems, Inc.
    Inventors: Darrell J. Johnson, John C. McCosh
  • Patent number: 7088088
    Abstract: A method of measuring a device under test (“DUT”) includes applying a pulsed-RF input signal to the DUT and coupling an output of the DUT to a receiver having an output bandwidth selected to measure a center tone in an RF pulse response spectrum from the output of the DUT. The receiver is triggered so as to sample data output from the DUT during a window period, and stops taking data after the window period.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: August 8, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Michael S. Marzalek, David J. Ballo
  • Patent number: 6995553
    Abstract: Measurements for an eye diagram of a signal of interest are placed in a data structure that is examined to locate an eye opening of interest. The eye opening of interest has already been, or is subsequently, normalized into figure of merit units related to the operational voltage and timing requirements of the data receiver for that signal. The locations within the normalized eye opening may be taken as center locations for trial symmetric shapes that start out small and are enlarged until they first include locations not part of the normalized eye opening. The center of a largest such shape is mapped back into the units of the original eye diagram as optimum sampling parameters for data analysis equipment that uses the receiver to sample the signal once per unit interval to discover logical value. An alternative is to repeatedly remove the ‘outer layer’ of the normalized eye opening until only one location remains.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: February 7, 2006
    Assignee: Agilent Technologies, Inc.
    Inventor: Richard A Nygaard, Jr.
  • Patent number: 6989663
    Abstract: A calibration system for measurement device is operable to calibrate each channel response to compensate its own gain error for a desired frequency range. The channel modes may include voltage range and a coupling mode. Each channel of the plurality of channels may have a certain number of channel mode combinations, including different voltage ranges and coupling modes. Each channel also may have a different frequency response, and as a result each channel mode combination may require an individual digital filter. As a result, the frequency response of each channel may be characterized and the digital filter may be designed to flatten each channel mode combination. The designed filter coefficients for each of the one or more channels of the plurality of channels may be stored in the measurement device. The filter coefficients may be used by a digital filter in order to compensate each one of the one or more channels on the measurement device.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: January 24, 2006
    Assignee: National Instruments Corporation
    Inventor: James Nagle
  • Patent number: 6934649
    Abstract: The present invention provides a waveform detection system and a state-monitoring system. The waveform detection system features a signal-processing function that characterizes and detects non-cyclic transient variations and performs 1/f fluctuation conversion for input waveforms to derive output waveforms. The waveform detection system characterizes signs of state variation, incorporates multiple digital filters in the digital filter calculator of the computer, uses coefficient patterns derived from non-integer n-time integration as elemental patterns for multiplication coefficient patterns, and incorporates a manner of changing the phase of at least one of the elemental patterns, input signal data, and digital filter output so that the outputs of digital filters that use the elemental patterns are synthesized in a state where a portion of the phases of the characteristic extracting and processing function is changed.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: August 23, 2005
    Assignee: Synchro Kabushiki Kaisha
    Inventors: Youichi Ageishi, Tetsuyuki Wada
  • Patent number: 6885181
    Abstract: An apparatus is provided to calibrate a target electrical circuit. The target electrical circuit includes at least a first variable capacitor and a first resistive element. The apparatus includes a second variable capacitor proportionally matched to the first variable capacitor. The apparatus also includes a measurement branch having at least a second resistive element proportionally matched to the first resistive element, and a current generator to generate a current proportionally matched to a predicted current of the target circuit. The apparatus also includes a digital loop to generate a digital code based on at least a comparison between a first voltage signal of the measurement branch and a predetermined voltage.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: April 26, 2005
    Assignee: Marvell International Ltd.
    Inventor: Pierte Roo
  • Patent number: 6784653
    Abstract: An eye monitor for evaluating a binary input signal of a transmission link and for recognizing the edges of an eye diagram of the input signal is described. A decision circuit is provided which is directly connected to an integrator. The input signal and a variable threshold are provided to the decision circuit. An output signal of the integrator is used to recognize the edges of the eye diagram.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: August 31, 2004
    Assignee: Alcatel
    Inventor: Wolfgang Baumert
  • Patent number: 6737851
    Abstract: An apparatus is provided to calibrate a target electrical circuit. The target electrical circuit includes at least a first variable capacitor and a first resistive element. The apparatus includes a second variable capacitor proportionally matched to the first variable capacitor. The apparatus also includes a measurement branch having at least a second resistive element proportionally matched to the first resistive element, and a current generator to generate a current proportionally matched to a predicted current of the target circuit. The apparatus also includes a digital loop to generate a digital code based on at least a comparison between a first voltage signal of the measurement branch and a predetermined voltage.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: May 18, 2004
    Assignee: Marvell International, Ltd.
    Inventor: Pierte Roo
  • Patent number: 6577990
    Abstract: A method is provided to process system test data to determine certification parameters of the system based on the test data. For a torpedo launch system, the velocity data is generated by a Pressure/Velocity/Displacement housing interfaced with a computer based data acquisition system and known launch system and test parameters, such as sample rate, muzzle exit length, time of acquisition, decimation factor and low pass cutoff frequency are provided as inputs. The method forces assigns a value of zero to any data less than a predetermined threshold in order to eliminate non-zero levels contributed by ambient noise. The method then passes the data through a filter chosen to agree with hand fit smoothing methods, so as to obtain a smoothed velocity profile. The smoothed data is processed to obtain and display an acceleration profile and a displacement profile, as well as data points for peak acceleration, time at peak, acceleration pulse width, muzzle exit velocity and time at exit.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: June 10, 2003
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Dominik A. Kotlow, Peter R. Witting, James W. Coleman
  • Patent number: 6577114
    Abstract: An apparatus is provided to calibrate a target electrical circuit. The target electrical circuit includes at least a first variable capacitor and a first resistive element. The apparatus includes a second variable capacitor proportionally matched to the first variable capacitor. The apparatus also includes a measurement branch having at least a second resistive element proportionally matched to the first resistive element, and a current generator to generate a current proportionally matched to a predicted current of the target circuit. The apparatus also includes a digital loop to generate a digital code based on at least a comparison between d first voltage signal of the measurement branch and a predetermined voltage.
    Type: Grant
    Filed: July 31, 2000
    Date of Patent: June 10, 2003
    Assignee: Marvell International, Ltd.
    Inventor: Pierte Roo
  • Patent number: 6574573
    Abstract: A spectrum analysis method and apparatus for processing and displaying time series data. The time series data in digital form is decomposed into a plurality of frequency components by means of a set of band pass filters. Adjacent band pass filters have their cut-off frequencies shifted or offset from each other by their passing band widths. Amplitude information of the frequency components may be obtained. For example, the frequency components generated by the band pass filters may be sampled in amplitude at predetermined time intervals. Such sampled amplitudes are then transformed into corresponding densities of a predetermined color including a gray color according to a color (or gray) scale, and displayed on a screen on the basis of a time base of the screen.
    Type: Grant
    Filed: December 16, 1999
    Date of Patent: June 3, 2003
    Assignee: Gram Corporation
    Inventor: Fumitaka Asano
  • Publication number: 20030062885
    Abstract: The invention provides a method for removing noise spikes from an electrical input signal having an AC component, comprising the steps of determining the actual rms value of the input signal, low pass filtering the input signal, producing a variable offset, said variable offset being a function of the actual rms value, forming a variable threshold by superimposing the variable offset to the low pass filtered signal, comparing the input signal to the variable threshold, creating a spike detection signal when the input signal passes the variable threshold, and blanking the input signal during the occurrence of the spike detection signal.
    Type: Application
    Filed: June 28, 2002
    Publication date: April 3, 2003
    Applicant: STMicroelectronics GmbH
    Inventor: Oscar Ballan
  • Patent number: 6525519
    Abstract: An amplitude detecting circuit (1) includes a simple digital filter (2) having a structure corresponding to a part where the energy is concentrated in the full impulse response of a signal processing digital filter (3). Concretely, for example, the amplitude detecting circuit (1) (simple digital filter (2)) includes only four central taps having coefficients of large absolute values and considerably affecting on the output amplitude among sixteen taps of the signal processing digital filter (3). By the amplitude detecting circuit (1), the amplitude of an output signal of the signal processing digital filter (3) can approximately be detected.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: February 25, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kimiaki Ando, Hiroki Shinde
  • Patent number: 6493024
    Abstract: A digital video signal monitoring apparatus comprises means (2,4,6) for receiving a digital video signal and extracting therefrom a plurality of digital signals, each of which comprises a plurality of successive digital sample values. The apparatus further comprises means (10) for interpolating additional digital values intermediate the successive samples of the or each extracted digital signal and means for displaying the waveform of the or each extracted digital signal as a series of discrete points corresponding to its respective digital sample values and interpolated digital values. Thus, none of the original signal information is lost in displaying a signal waveform having a substantially continuous appearance.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: December 10, 2002
    Assignee: Hamlet Video International Limited
    Inventors: Richard Hartley, David Thomas Hartley
  • Patent number: 6351505
    Abstract: A method for determining a frequency of a signal includes transforming the analog signal to the complex frequency range through a digital filtering, preferably a FFT, so that result vectors with amplitude and phase components are generated in the frequency range. As a result, a continuous sequence of transformation intervals (FFT intervals) develops within a measuring interval that can be predetermined. Subsequently, pairs of result vectors, which belong to the same predetermined frequency, are selected from predetermined transformation intervals (FFT intervals). Associated phase differences are then formed from which a weighted phase difference is determined. The weighted phase difference is used to correct the signal frequency determined from the amplitude spectrum. This method permits very accurate frequency measuring, especially for pulsed HF signals.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: February 26, 2002
    Assignee: Daimler-Benz Aerospace AG
    Inventors: Franz Herrmann, Manfred Schuster