Patents by Inventor Jeffrey D. Earls

Jeffrey D. Earls has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9621286
    Abstract: A signal generation system can include an input source configured to provide an input radio frequency (RF) signal, a correction filter calculation (CFC) block configured to determine correction filter parameters, and an automatic level control (ALC) loop configured to provide ALC loop information to the CFC block. The correction filter parameters may be determined based at least in part on the ALC information. The system can also include a predistortion field programmable gate array (FPGA) configured to apply a correction filter to the input RF signal, wherein the correction filter is based at least in part on the correction filter parameters, and an RF output configured to provide an RF output signal.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: April 11, 2017
    Assignee: Tektronix, Inc.
    Inventor: Jeffrey D. Earls
  • Patent number: 8872569
    Abstract: An automatic quadrature network with amplitude and phase detection produces quadrature signals for an input oscillator signal, the quadrature signals being equal in amplitude and having ideal quadrature phase between them. An RC circuit provides one quadrature path, and a CR circuit provides another quadrature path. The outputs from the RC/CR circuits are amplitude detected to produce an amplitude control signal. The outputs also are amplitude limited, and the phase between the limiter outputs is detected to produce a phase control signal. The amplitude and phase control signals are combined to generate respective control signals for the RC/CR circuits to automatically align them so that the quadrature signals are of equal amplitude and ideal quadrature phase.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: October 28, 2014
    Assignee: Tektronix, Inc.
    Inventors: Kelly F. Garrison, Raymond L. Veith, Gordon A. Olsen, Jeffrey D. Earls
  • Publication number: 20140139279
    Abstract: An automatic quadrature network with amplitude and phase detection produces quadrature signals for an input oscillator signal, the quadrature signals being equal in amplitude and having ideal quadrature phase between them. An RC circuit provides one quadrature path, and a CR circuit provides another quadrature path. The outputs from the RC/CR circuits are amplitude detected to produce an amplitude control signal. The outputs also are amplitude limited, and the phase between the limiter outputs is detected to produce a phase control signal. The amplitude and phase control signals are combined to generate respective control signals for the RC/CR circuits to automatically align them so that the quadrature signals are of equal amplitude and ideal quadrature phase.
    Type: Application
    Filed: November 19, 2012
    Publication date: May 22, 2014
    Applicant: TEKTRONIX, INC
    Inventors: Kelly F. GARRISON, Raymond L. VEITH, Gordon A. OLSEN, Jeffrey D. EARLS
  • Publication number: 20130141466
    Abstract: The described test and measurement instrument includes a processor for generating a bitmap image from an input test signal, a user interface for identifying a portion of the bitmap image, and a second image generator structured to generate a second image from the identified portion of the bitmap image. The second image may be a zoomed image from the original bitmap, and the images may be time-corrected before being displayed.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 6, 2013
    Applicant: TEKTRONIX, INC
    Inventors: JEFFREY D. EARLS, FRANKLIN M. BORDEN, KELLY F. GARRISON
  • Publication number: 20130003889
    Abstract: A signal generation system can include an input source configured to provide an input radio frequency (RF) signal, a correction filter calculation (CFC) block configured to determine correction filter parameters, and an automatic level control (ALC) loop configured to provide ALC loop information to the CFC block. The correction filter parameters may be determined based at least in part on the ALC information. The system can also include a predistortion field programmable gate array (FPGA) configured to apply a correction filter to the input RF signal, wherein the correction filter is based at least in part on the correction filter parameters, and an RF output configured to provide an RF output signal.
    Type: Application
    Filed: June 29, 2011
    Publication date: January 3, 2013
    Applicant: TEKTRONIX, INC.
    Inventor: Jeffrey D. Earls
  • Patent number: 7873486
    Abstract: A spectrogram mask trigger is generated in response to multiple or complex frequency events within a signal being monitored. A sequence of frequency masks over a period of time is generated according to a frequency trajectory, frequency hops or other complex frequency events expected in the signal to form a spectrogram mask. The spectrogram mask is then applied to multiple spectra or spectrogram of the signal to determine whether an anomalous frequency event has occurred within the time period or to identify a particular frequency pattern within the signal. Depending upon the results of the spectrogram mask application, the spectrogram mask trigger is generated for storing a block of data from the signal surrounding the triggering event for further analysis.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: January 18, 2011
    Assignee: Tektronix, Inc.
    Inventor: Jeffrey D. Earls
  • Patent number: 7702305
    Abstract: An instrumentation receiver architecture for processing an RF signal has a dual-IF channel architecture, a low-band IF channel and a high-band IF channel, and a tunable oscillator, such as a yttrium-iron-garnet (YIG) tunable oscillator (YTO), a voltage controlled oscillator (VCO), a bank of VCOs and the like, providing a different mixing frequency range to each channel, generally a higher frequency range to the high-band IF channel than to the low-band IF channel. At the input to the high-band IF channel is a bank of preselection filters for selecting a frequency band from the RF signal for processing by the high-band IF channel. A switch selects the output from one of the low-band and high-band IF channels for further processing.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: April 20, 2010
    Assignee: Tektronix, Inc.
    Inventor: Jeffrey D. Earls
  • Patent number: 7352827
    Abstract: An instrumentation receiver for multichannel simultaneously realtime spectrum analysis with frequency trigger offset inputs a wideband IF signal derived from a wideband RF signal by the receiver to both a wideband IF channel and a narrowband IF channel simultaneously. The wideband IF signal output from the wideband IF channel is sampled at a high sample rate with relatively low resolution to produce wideband signal data. The wideband IF signal input to the narrowband IF channel is frequency offset by a variable amount according to a region in the wideband IF signal where a frequency trigger event is expected and then narrowband filtered to produce a narrowband IF signal. The narrowband IF signal is sampled at a relatively low sample rate with high resolution to produce high dynamic range signal data for input to a frequency trigger function.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: April 1, 2008
    Assignee: Tektronix, Inc.
    Inventors: Jeffrey D. Earls, Alfred K. Hillman, Jr.
  • Patent number: 7327992
    Abstract: A tracking generator for an RF measurement instrument having a receiver and a controller includes a vector modulator internal to the tracking generator. The internal vector modulator modulates complex baseband signals based on data from the controller to produce a vector modulation signal. The vector modulation signal is used to modulate a local oscillator frequency from the receiver in an output mixing stage to produce a test signal having an output frequency that matches a measurement frequency to which the receiver is tuned. By controlling the complex baseband data from the controller, an adaptive filter at the output of a DAC that produces an analog signal from the digitally modulated complex baseband data, an internal independent oscillator for the vector modulator, or a large offset phase-locked loop, an offset from the measurement frequency may be generated for the output frequency.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: February 5, 2008
    Assignee: Tektronix, Inc.
    Inventors: Jeffrey D. Earls, Donald J. Dalebroux
  • Patent number: 6785527
    Abstract: A method of avoiding conversion spurs in a multi-conversion radio frequency receiver having a first local oscillator, an intermediate frequency filter and a second local oscillator in series generates, based on a center frequency for the intermediate frequency filter, a table of problem frequencies of the first local oscillator relative to a frequency of the second local oscillator which produce harmonic mixing products within the bandwidth of the intermediate frequency filter versus corresponding frequency offsets for the second local oscillator which retune the frequency of the second local oscillator so the harmonic mixing products are moved outside the bandwidth of the intermediate frequency filter.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: August 31, 2004
    Assignee: Tektronix, Inc.
    Inventor: Jeffrey D. Earls
  • Patent number: 6532358
    Abstract: Overload distortion protection for a wideband receiver having a wideband variable gain input amplifier followed by a frequency conversion stage followed in turn by an intermediate frequency amplifier and detector to produce a measurement value in response to a signal input to the wideband variable gain input amplifier is achieved by detecting the peak power of the signal at the output of the wideband variable gain input amplifier and comparing it with the power output from the intermediate frequency amplifier and detector. If a threshold difference is exceeded, gain control signals for the wideband variable gain input and intermediate frequency amplifiers are adjusted for optimum dynamic range. If there is no range for adjusting the gain control signals, then a warning is provided to an operator to alert that the measurement value may contain distortion.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: March 11, 2003
    Assignee: Tektronix, Inc.
    Inventors: Jeffrey D. Earls, Donald J. Dalebroux, Man-Kit Yau
  • Publication number: 20020142748
    Abstract: A method of avoiding conversion spurs in a multi-conversion radio frequency receiver having a first local oscillator, an intermediate frequency filter and a second local oscillator in series generates, based on a center frequency for the intermediate frequency filter, a table of problem frequencies of the first local oscillator relative to a frequency of the second local oscillator which produce harmonic mixing products within the bandwidth of the intermediate frequency filter versus corresponding frequency offsets for the second local oscillator which retune the frequency of the second local oscillator so the harmonic mixing products are moved outside the bandwidth of the intermediate frequency filter.
    Type: Application
    Filed: April 2, 2001
    Publication date: October 3, 2002
    Inventor: Jeffrey D. Earls
  • Patent number: 6307896
    Abstract: An instrumentation receiver suitable for receiving a digitally modulated radio frequency input signal having a pilot signal at the RF frequency and symbol data generated at a symbol frequency generates a digitally modulated intermediate frequency signal having the pilot signal at the intermediate frequency equal to an integer multiple of the digital data's symbol frequency where the integer multiple is equal to or greater than one. A reference signal having a frequency equal to an integer multiple of the symbol frequency where the integer multiple is equal to or greater than one mixes with the IF signal to generate a control signal for controlling a local oscillator that generates a local oscillator signal for mixing with the digitally modulated RF input signal for locking the pilot signal to the reference signal.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: October 23, 2001
    Assignee: Tektronix, Inc.
    Inventors: Linley F. Gumm, Jeffrey D. Earls