Patents by Inventor Joel L. Dawson
Joel L. Dawson 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).
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Publication number: 20140118065Abstract: Circuits and methods for achieving high linearity, high efficiency power amplifiers, including digital predistortion (DPD) and pulse cancellation in switched-state RF power amplifier systems are described.Type: ApplicationFiled: October 28, 2013Publication date: May 1, 2014Applicant: Eta Devices, Inc.Inventors: Mark A. Briffa, Joel L. Dawson, John E. DeRoo, Krenar Komoni, David J. Perreault, Oguzhan Uyar
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Publication number: 20140120854Abstract: A radio frequency (RF) transmitter includes one or more power amplifiers and a controller that is configured to adjust amplitudes and phases of RF input signals of the one or more power amplifiers and supply voltages applied to the one or more power amplifiers. In embodiments where multiple power amplifiers are used, a combiner may be provided to combine outputs of the power amplifiers. In at least one implementation, amplitude adjustment of the RF input signals of the one or more power amplifiers may be used to provide transmit power control and/or power backoff for the RF transmitter.Type: ApplicationFiled: October 30, 2012Publication date: May 1, 2014Applicant: ETA Devices, Inc.Inventors: Mark A. Briffa, Joel L. Dawson, John E. DeRoo, Krenar Komoni, David J. Perreault, Oguzhan Uyar
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Publication number: 20140118063Abstract: A radio frequency (RF) power amplifier system or transmitter includes one or more power amplifiers and a controller that is configured to adjust amplitudes and phases of RF input signals of the one or more power amplifiers and supply voltages applied to the one or more power amplifiers. In embodiments where multiple power amplifiers are used, a combiner may be provided to combine outputs of the power amplifiers. In at least one implementation, amplitude adjustment of the RF input signals of the one or more power amplifiers may be used to provide transmit power control and/or power backoff.Type: ApplicationFiled: October 30, 2012Publication date: May 1, 2014Applicant: ETA Devices, Inc.Inventors: Mark A. Briffa, Joel L. Dawson, John E. DeRoo, Krenar Komoni, David J. Perreault, Oguzhan Uyar
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Patent number: 8659353Abstract: A radio frequency (RF) circuit includes a power supply configured to generate a plurality of voltages, a plurality of power amplifiers, each having an RF output port and a power supply input port, a switch network having a plurality of input ports coupled to the power supply and a plurality of switch network output ports coupled to the power supply input ports of the plurality of power amplifiers, wherein the switch network is configured to output selected ones of the plurality of voltages from the plurality of switch network output ports, at least two of the switch network output port voltages capable of being different ones of the plurality of voltages, and an RF power combiner circuit having a plurality of input ports coupled to RF output ports of the plurality of power amplifiers and an output port at which is provided an output signal of the RF circuit.Type: GrantFiled: March 19, 2012Date of Patent: February 25, 2014Assignee: Massachusetts Institute of TechnologyInventors: Joel L. Dawson, David J. Perreault, SungWon Chung, Philip Godoy, Everest Huang
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Publication number: 20130343106Abstract: An energy recovery system is provided that can be used in place of a resistive termination. The energy recovery system can simulate the behavior and performance of a resistive termination, while recovering at least some of the energy that would otherwise have been dissipated within the termination. In one embodiment, the energy recovery system includes a rectification system having a plurality of tuned rectifier circuits and an RF input network to provide input power distribution to the plurality of tuned rectifier circuits and input impedance shaping to shape the collective input impedance of the plurality of tuned rectifier circuits as seen at the RF input port of the RF input network.Type: ApplicationFiled: January 31, 2013Publication date: December 26, 2013Applicant: ETA DEVICES, INC.Inventors: David J. Perreault, Joel L. Dawson
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Publication number: 20120245436Abstract: A device for determining muscle condition of a region of tissue. The device comprises an electrical impedance myography (EIM) portable probe bearing an electrode array. The electrode array comprises excitation electrodes used to apply multi-frequency electrical signals to the region of tissue and pickup electrodes that are used to collect electrical signals resulting from the application of the multi-frequency electrical signals to the region of tissue. To improve accuracy and reproducibility of EIM measurements, the electrode array is reconfigurable to select different subsets of excitation and pickup electrodes so that the electrodes are oriented differently with respect to muscle fibers. Additional devices may be associated with the EIM probe to measure such parameters as temperature, moisture content of the region, quality of contact of electrodes of the electrode array with a surface of the region and pressure with which the EEM probe is applied to the region.Type: ApplicationFiled: August 20, 2010Publication date: September 27, 2012Applicant: Beth Israel Deaconess Medical Center Inc.Inventors: Seward B. Rutkove, Joel L. Dawson
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Publication number: 20120176195Abstract: A radio frequency (RF) circuit includes a power supply configured to generate a plurality of voltages, a plurality of power amplifiers, each having an RF output port and a power supply input port, a switch network having a plurality of input ports coupled to the power supply and a plurality of switch network output ports coupled to the power supply input ports of the plurality of power amplifiers, wherein the switch network is configured to output selected ones of the plurality of voltages from the plurality of switch network output ports, at least two of the switch network output port voltages capable of being different ones of the plurality of voltages, and an RF power combiner circuit having a plurality of input ports coupled to RF output ports of the plurality of power amplifiers and an output port at which is provided an output signal of the RF circuit.Type: ApplicationFiled: March 19, 2012Publication date: July 12, 2012Applicant: Massachusetts Institute of TechnologyInventors: Joel L. Dawson, David J. Perreault, SungWon Chung, Philip Godoy, Everest Huang
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Patent number: 8164384Abstract: A radio frequency (RF) circuit includes a power supply configured to generate a plurality of voltages, a plurality of power amplifiers, each having an RF output port and a power supply input port, a switch network having a plurality of input ports coupled to the power supply and a plurality of switch network output ports coupled to the power supply input ports of the plurality of power amplifiers, wherein the switch network is configured to output selected ones of the plurality of voltages from the plurality of switch network output ports, at least two of the switch network output port voltages capable of being different ones of the plurality of voltages, and an RF power combiner circuit having a plurality of input ports coupled to RF output ports of the plurality of power amplifiers and an output port at which is provided an output signal of the RF circuit.Type: GrantFiled: May 12, 2011Date of Patent: April 24, 2012Assignee: Massachusetts Institute of TechnologyInventors: Joel L. Dawson, David J. Perreault, SungWon Chung, Philip Godoy, Everest Huang
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Patent number: 8026763Abstract: A radio frequency (RF) circuit includes a power supply configured to generate a plurality of voltages, a plurality of power amplifiers, each having an RF output port and a power supply input port, a switch network having a plurality of input ports coupled to the power supply and a plurality of switch network output ports coupled to the power supply input ports of the plurality of power amplifiers, wherein the switch network is configured to output selected ones of the plurality of voltages from the plurality of switch network output ports, at least two of the switch network output port voltages capable of being different ones of the plurality of voltages, and an RF power combiner circuit having a plurality of input ports coupled to RF output ports of the plurality of power amplifiers and an output port at which is provided an output signal of the RF circuit.Type: GrantFiled: November 10, 2009Date of Patent: September 27, 2011Assignee: Massachusetts Institute of TechnologyInventors: Joel L. Dawson, David J. Perreault, SungWon Chung, Philip Godoy, Everest Huang
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Publication number: 20110215866Abstract: A radio frequency (RF) circuit includes a power supply configured to generate a plurality of voltages, a plurality of power amplifiers, each having an RF output port and a power supply input port, a switch network having a plurality of input ports coupled to the power supply and a plurality of switch network output ports coupled to the power supply input ports of the plurality of power amplifiers, wherein the switch network is configured to output selected ones of the plurality of voltages from the plurality of switch network output ports, at least two of the switch network output port voltages capable of being different ones of the plurality of voltages, and an RF power combiner circuit having a plurality of input ports coupled to RF output ports of the plurality of power amplifiers and an output port at which is provided an output signal of the RF circuit.Type: ApplicationFiled: May 12, 2011Publication date: September 8, 2011Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGYInventors: Joel L. Dawson, David J. Perreault, SungWon Chung, Philip Godoy, Everest Huang
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Publication number: 20100117727Abstract: A radio frequency (RF) circuit includes a power supply configured to generate a plurality of voltages, a plurality of power amplifiers, each having an RF output port and a power supply input port, a switch network having a plurality of input ports coupled to the power supply and a plurality of switch network output ports coupled to the power supply input ports of the plurality of power amplifiers, wherein the switch network is configured to output selected ones of the plurality of voltages from the plurality of switch network output ports, at least two of the switch network output port voltages capable of being different ones of the plurality of voltages, and an RF power combiner circuit having a plurality of input ports coupled to RF output ports of the plurality of power amplifiers and an output port at which is provided an output signal of the RF circuit.Type: ApplicationFiled: November 10, 2009Publication date: May 13, 2010Applicant: Massachusetts Institute of TechnologyInventors: Joel L. Dawson, David J. Perreault, SungWon Chung, Philip Godoy, Everest Huang
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Patent number: 7433420Abstract: Apparatus, systems, and methods are described that implement techniques for estimating a relative rotation between a first complex signal and a second complex signal. In apparatus form, a rotation-estimation circuit includes a first quadrant detector and receives the first and second complex signals and produces an estimate of the relative rotation between the complex signals. A variable rotator receives the estimate of the relative rotation and rotates at least one of the first and second complex signals using the estimate of the relative rotation. In method form, a first quadrant estimate is calculated that corresponds to the relative rotation between the first and second complex signals, and at least one of the first and second complex signals is rotated using the quadrant estimate of the relative rotation.Type: GrantFiled: February 18, 2005Date of Patent: October 7, 2008Assignee: Beceem Communications Inc.Inventors: Sriraman Dakshinamurthy, Joel L. Dawson, Derek K. Shaeffer, Korhan Titizer
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Patent number: 7382834Abstract: Apparatus, systems, and methods implementing techniques for estimating a relative rotation between a first complex signal and a second complex signal. The first complex signal is quantized to produce a quantized signal, and the quantized signal and an additional signal are combined, where the additional signal corresponds to the second complex signal. An estimate of a relative rotation between the first complex signal and the second complex signal is generated in accordance with the combined signal.Type: GrantFiled: May 6, 2004Date of Patent: June 3, 2008Assignee: Beceem Communications Inc.Inventors: Joel L. Dawson, Sriraman Dakshinamurthy, Derek K. Shaeffer
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Patent number: 7177366Abstract: In an automatic phase alignment circuit for a Cartesian feedback amplifier, the phase error is regularly monitored. In various implementations, this approach is used to provide true and continuous phase alignment. Based on a relationship between the up-converted and down-converted signals, another implementation of the invention provides phase-alignment for quadrature-phase components of a baseband signal by arithmetically combining the quadrature-phase components and the feedback components continuously and, in response, continuously phase-adjusting signals in the feed-forward signal path. Another aspect of the present invention is directed to an approach for calculating phase error for that is caused by DC-offset interference which, in turn, manifest at the outputs of many analog functional blocks.Type: GrantFiled: September 6, 2001Date of Patent: February 13, 2007Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Joel L. Dawson, Thomas H. Lee
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Patent number: 5940291Abstract: In accordance with one embodiment of the present intention, an adaptive feedback controller is configured to substantially reduce an error control signal defined by the difference between a command signal and the output signal of a controlled device. The adaptive controller comprises a step generator circuit configured to provide a control signal which is employed to vary the input signal received by the controlled device, The control signal is substantially in the shape of a ramp signal having a given slew rate. An adaptive slew rate computation circuit is coupled to the step generator so as to provide a slew rate compensation signal to the step generator to increase the slew rate of the control signal, when the controlled device is responding to a substantially fast varying input signal. The slew rate compensation circuit decreases the slew rate of the control signal, when the controlled device is responding to a slow varying input signal.Type: GrantFiled: May 8, 1997Date of Patent: August 17, 1999Assignee: Lucent Technologies Inc.Inventors: Joel L. Dawson, Jenshan Lin, Young-Kai Chen