Patents by Inventor Walter Haley
Walter Haley 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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Patent number: 7061313Abstract: A dual feedback topology imparts stability to a multistage linear amplifier, particularly by improving overall amplifier phase margin at higher signal frequencies. With dual feedback, an inner feedback loop is closed around the first amplifier stage, which stage is configured as a current feedback amplifier. A second feedback loop is closed around the overall multistage amplifier. With a current feedback amplifier as the initial stage, the two feedback signals are current-mode signals and thus add to form the combined feedback signal. The frequency responses of the inner and outer feedback loops may be tailored for flat frequency response, or, where desired, may be adjusted to compensate or otherwise flatten overall amplifier frequency response.Type: GrantFiled: January 23, 2002Date of Patent: June 13, 2006Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Donald Felt Kimball, Joseph L. Archambault, Walter Haley, Lennart Mathe
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Patent number: 6792252Abstract: An error amplifier circuit reduces distortion in an amplified signal by reflecting a feedback signal into the amplified signal using an output transformer. A first amplifier generates a reference signal corresponding to the input signal from which the amplifier output signal is derived. This reference signal represents the desired waveform for the amplified signal. An error sense element generates an error signal based on the difference between the reference and amplified signals. The error sense element preferably imparts high common-mode rejection to the error signal. A second amplifier generates the feedback signal based on amplifying the error signal, and an output transformer generates a compensated amplified signal by coupling the feedback signal into the amplified signal. The output transformer increases the reflected load impedance seen by the error amplifier, thus relieving it from driving the feedback signal into the potentially low load impedance driven by the compensated amplified signal.Type: GrantFiled: February 6, 2002Date of Patent: September 14, 2004Assignee: Telefonaktiebolaget LM Ericsson (Publ)Inventors: Donald Felt Kimball, Joseph L. Archambault, Walter Haley, Lennart Mathe
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Patent number: 6661210Abstract: A capacitorless DC-DC converter provides a controlled output voltage to a load, and includes a relatively wide bandwidth linear regulator placed in parallel with a switching regulator. Output signals from the linear regulator and switching regulator are added to form a combined output signal provided to the load. The switching regulator provides steady state current to the load, while the linear regulator provides higher-frequency transient current as needed. Because the linear regulator's transient response compensates for the limited transient response of the switching regulator, the substantial low-ESR output capacitance that is customarily required by conventional switching regulators is not needed. Further, feedback to the linear regulator taken from the combined output signal causes it to generate anti-phase ripple compensation, thereby reducing the magnitude of switching ripple in the converter's combined output signal.Type: GrantFiled: January 23, 2002Date of Patent: December 9, 2003Assignee: Telfonaktiebolaget L.M. EricssonInventors: Donald Kimball, Joseph Archambault, Walter Haley
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Patent number: 6661217Abstract: A wideband precision current sensor employs DC-coupled and AC-coupled sensing circuits to generate lower and higher frequency sense signals; which are combined to form a wideband output signal that is proportional to a wideband current of interest. The frequency response of the wideband output signal is substantially flat across a wideband frequency range, 0 to 30 MHz for example, based on matching the frequency response of the DC- and AC-coupled sensing circuits. In an exemplary application, the current sensor provides feedback to a supply voltage (Vdd) amplifier used in RF envelope elimination and restoration (EER) applications.Type: GrantFiled: December 21, 2001Date of Patent: December 9, 2003Assignee: Telefonaktiebolaget L.M. EricssonInventors: Donald Felt Kimball, Joseph L. Archambault, Walter Haley, Lennart Mathe
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Publication number: 20030148792Abstract: An error amplifier circuit reduces distortion in an amplified signal by reflecting a feedback signal into the amplified signal using an output transformer. A first amplifier generates a reference signal corresponding to the input signal from which the amplifier output signal is derived. This reference signal represents the desired waveform for the amplified signal. An error sense element generates an error signal based on the difference between the reference and amplified signals. The error sense element preferably imparts high common-mode rejection to the error signal. A second amplifier generates the feedback signal based on amplifying the error signal, and an output transformer generates a compensated amplified signal by coupling the feedback signal into the amplified signal. The output transformer increases the reflected load impedance seen by the error amplifier, thus relieving it from driving the feedback signal into the potentially low load impedance driven by the compensated amplified signal.Type: ApplicationFiled: February 6, 2002Publication date: August 7, 2003Inventors: Donald Felt Kimball, Joseph L. Archambault, Walter Haley
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Publication number: 20030137344Abstract: A dual feedback topology imparts stability to a multistage linear amplifier, particularly by improving overall amplifier phase margin at higher signal frequencies. With dual feedback, an inner feedback loop is closed around the first amplifier stage, which stage is configured as a current feedback amplifier. A second feedback loop is closed around the overall multistage amplifier. With a current feedback amplifier as the initial stage, the two feedback signals are current-mode signals and thus add to form the combined feedback signal. The frequency responses of the inner and outer feedback loops may be tailored for flat frequency response, or, where desired, may be adjusted to compensate or otherwise flatten overall amplifier frequency response.Type: ApplicationFiled: January 23, 2002Publication date: July 24, 2003Inventors: Donald Felt Kimball, Joseph L. Archambault, Walter Haley, Lennart Mathe
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Publication number: 20030137286Abstract: A capacitorless DC-DC converter provides a controlled output voltage to a load, and includes a relatively wide bandwidth linear regulator placed in parallel with a switching regulator. Output signals from the linear regulator and switching regulator are added to form a combined output signal provided to the load. The switching regulator provides steady state current to the load, while the linear regulator provides higher-frequency transient current as needed. Because the linear regulator's transient response compensates for the limited transient response of the switching regulator, the substantial low-ESR output capacitance that is customarily required by conventional switching regulators is not needed. Further, feedback to the linear regulator taken from the combined output signal causes it to generate anti-phase ripple compensation, thereby reducing the magnitude of switching ripple in the converter's combined output signal.Type: ApplicationFiled: January 23, 2002Publication date: July 24, 2003Inventors: Donald Kimball, Joseph L. Archambault, Walter Haley
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Publication number: 20030117123Abstract: A wideband precision current sensor employs DC-coupled and AC-coupled sensing circuits to generate lower and higher frequency sense signals, which are combined to form a wideband output signal that is proportional to a wideband current of interest. The frequency response of the wideband output signal is substantially flat across a wideband frequency range, 0 to 30 MHz for example, based on matching the frequency response of the DC- and AC-coupled sensing circuits. In an exemplary application, the current sensor provides feedback to a supply voltage (Vdd) amplifier used in RF envelope elimination and restoration (EER) applications.Type: ApplicationFiled: December 21, 2001Publication date: June 26, 2003Inventors: Donald Felt Kimball, Joseph L. Archambault, Walter Haley, Lennart Mathe
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Patent number: 6583664Abstract: Systems and methods for amplifying an RF input signal include employing a moderately power efficient wide bandwidth device, such as an AB-type amplifier, to amplify the power residing in the high frequency components of the input signal, and a highly power efficient narrow bandwidth device, such as a synchronous buck DC/DC converter, to amplify the power residing in the low frequency components of the input signal. The amplified low frequency components and high frequency components are then combined to produce an amplified replica of the RF input signal. A positive feedback loop is provided between the output of the AB-type amplifier and the input of the DC/DC converter to provide stability to the amplified RF signal. A negative feedback loop is provided between the output of the DC/DC converter and the input of the AB-type amplifier to minimize interference introduced by the DC/DC converter.Type: GrantFiled: July 23, 2001Date of Patent: June 24, 2003Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Lennart Mathe, Don Kimball, Joe Archambault, Walter Haley
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Publication number: 20020008574Abstract: Systems and methods for amplifying an RF input signal include employing a moderately power efficient wide bandwidth device, such as an AB-type amplifier, to amplify the power residing in the high frequency components of the input signal, and a highly power efficient narrow bandwidth device, such as a synchronous buck DC/DC converter, to amplify the power residing in the low frequency components of the input signal. The amplified low frequency components and high frequency components are then combined to produce an amplified replica of the RF input signal. A positive feedback loop is provided between the output of the AB-type amplifier and the input of the DC/DC converter to provide stability to the amplified RF signal. A negative feedback loop is provided between the output of the DC/DC converter and the input of the AB-type amplifier to minimize interference introduced by the DC/DC converter.Type: ApplicationFiled: July 23, 2001Publication date: January 24, 2002Inventors: Lennart Mathe, Don Kimball, Joe Archambault, Walter Haley
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Patent number: 6300826Abstract: Systems and methods for amplifying an RF input signal include employing a moderately power efficient wide bandwidth device, such as an AB-type amplifier, to amplify the power residing in the high frequency components of the input signal, and a highly power efficient narrow bandwidth device, such as a synchronous buck DC/DC converter, to amplify the power residing in the low frequency components of the input signal. The amplified low frequency components and high frequency components are then combined to produce an amplified replica of the RF input signal. A positive feedback loop is provided between the output of the AB-type amplifier and the input of the DC/DC converter to provide stability to the amplified RF signal. A negative feedback loop is provided between the output of the DC/DC converter and the input of the AB-type amplifier to minimize interference introduced by the DC/DC converter.Type: GrantFiled: May 5, 2000Date of Patent: October 9, 2001Inventors: Lennart Mathe, Don Kimball, Joe Archambault, Walter Haley