Patents by Inventor Scott R. Justice

Scott R. Justice 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: 7072421
    Abstract: A digital signal processor generates in-phase, quadrature-phase and amplitude signals from a baseband signal. A modulator modulates the in-phase and quadrature-phase signals to produce a modulated signal. A phase locked loop is responsive to the modulated signal. The phase locked loop includes a controlled oscillator having a controlled oscillator input. An amplifier includes a signal input, amplitude control input and an output. The signal input is responsive to the controlled oscillator output and the amplitude control input is responsive to the amplitude signal. The phase locked loop that is responsive to the modulated signal includes a controlled oscillator output and a feedback loop between the controlled oscillator input and the controlled oscillator output. The feedback loop includes a mixer that is responsive to a local oscillator. The modulator may be placed in the phase locked loop.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: July 4, 2006
    Assignee: Telefonaktiebolaget L.M. Ericsson
    Inventors: Erik Bengtsson, Aristotle Hadjichristos, Scott R. Justice
  • Patent number: 6975686
    Abstract: A digital signal processor generates in-phase, quadrature-phase and amplitude signals from a baseband signal. A modulator modulates the in-phase and quadrature-phase signals to produce a modulated signal. A phase locked loop is responsive to the modulated signal. The phase locked loop includes a controlled oscillator having a controlled oscillator input. An amplifier includes a signal input, amplitude control input and an output. The signal input is responsive to the controlled oscillator output and the amplitude control input is responsive to the amplitude signal. The in-phase and quadrature-phase signals may be normalized in-phase and quadrature-phase signals. Alternatively, a phase tracking subsystem may be provided that is responsive to the quadrature modulator to produce a phase signal that is responsive to phase changes in the modulated signal and that is independent of amplitude changes in the modulated signal.
    Type: Grant
    Filed: October 31, 2000
    Date of Patent: December 13, 2005
    Assignee: Telefonaktiebolaget L.M. Ericsson
    Inventors: M. Ali Khatibzadeh, Aristotle Hadjichristos, Scott R. Justice, Steven G. Cairns, Charles Gore, Jr., Jeffrey Schlang, Erik Bengtsson, William O. Camp, Jr., David R. Pehlke
  • Patent number: 6909757
    Abstract: Embodiments of methods, transmitters, and computer program products are provided for transmitting a signal by adjusting a delay between an amplitude component of the signal and a phase component of the signal based on the transmission power. Error vector magnitude and adjacent channel power ratio are two common criteria used in evaluating transmitter performance. By adjusting the delay between the amplitude component of the transmitted signal and the phase component of the transmitted signal, the error vector magnitude and/or the adjacent channel power ratio may be reduced. The particular delay value that provides the best error vector magnitude performance and/or adjacent channel power ratio performance may differ based on the transmission power level. Therefore, the delay value is adjusted based on the transmission power.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: June 21, 2005
    Assignee: Ericsson Inc.
    Inventors: Scott R. Justice, Erik L. Bengtsson, David R. Pehlke
  • Publication number: 20020168020
    Abstract: Embodiments of methods, transmitters, and computer program products are provided for transmitting a signal by adjusting a delay between an amplitude component of the signal and a phase component of the signal based on the transmission power. Error vector magnitude and adjacent channel power ratio are two common criteria used in evaluating transmitter performance. By adjusting the delay between the amplitude component of the transmitted signal and the phase component of the transmitted signal, the error vector magnitude and/or the adjacent channel power ratio may be reduced. The particular delay value that provides the best error vector magnitude performance and/or adjacent channel power ratio performance may differ based on the transmission power level. Therefore, the delay value is adjusted based on the transmission power.
    Type: Application
    Filed: May 14, 2001
    Publication date: November 14, 2002
    Inventors: Scott R. Justice, Erik L. Bengtsson, David R. Pehlke
  • Patent number: 6424229
    Abstract: Voltage controlled oscillator circuits are provided including a voltage controlled oscillator (VCO) having an input and an output responsive to the input. A tuning circuit coupled to the VCO sets a relationship between the input and the output of the VCO. An aided acquisition circuit is coupled to the input of the VCO. A control circuit selects a state of the tuning circuit to set the relationship between the input and the output of the VCO. The control circuit also controls operation of the aided acquisition circuit responsive to changes in the state of the tuning circuit. Methods for operating voltage controlled oscillator circuits are also provided. In addition, phase lock loop circuits and mobile terminals including the voltage controlled oscillator circuits are provided.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: July 23, 2002
    Assignee: Ericsson Inc.
    Inventors: Scott R. Justice, Erik L. Bengtsson
  • Publication number: 20020071497
    Abstract: A digital signal processor generates in-phase, quadrature-phase and amplitude signals from a baseband signal. A modulator modulates the in-phase and quadrature-phase signals to produce a modulated signal. A phase locked loop is responsive to the modulated signal. The phase locked loop includes a controlled oscillator having a controlled oscillator input. An amplifier includes a signal input, amplitude control input and an output. The signal input is responsive to the controlled oscillator output and the amplitude control input is responsive to the amplitude signal. The phase locked loop that is responsive to the modulated signal includes a controlled oscillator output and a feedback loop between the controlled oscillator input and the controlled oscillator output. The feedback loop includes a mixer that is responsive to a local oscillator. The modulator may be placed in the phase locked loop.
    Type: Application
    Filed: December 22, 2000
    Publication date: June 13, 2002
    Inventors: Erik Bengtsson, Aristotle Hadjichristos, Scott R. Justice
  • Patent number: 6366162
    Abstract: An input buffer circuit is operable to selectively present either low or high input impedance while maintaining uniform output impedance. The buffer is characterized by first and second amplifier circuits connected in parallel between an input to and an output from the buffer. The amplifiers are individually controlled between enabled and disabled states. When enabled, the first amplifier has low input impedance and predetermined output impedance and the second amplifier has high input impedance and the predetermined output impedance, and when disabled each amplifier has high input and output impedance. To operate the buffer to have low input impedance, the first amplifier is enabled while the second amplifier is disabled. To operate the buffer to have high input impedance, the second amplifier is enabled while the first amplifier is disabled.
    Type: Grant
    Filed: January 2, 2001
    Date of Patent: April 2, 2002
    Assignee: Ericsson Inc.
    Inventors: Chris W. Angell, Erik L. Bengtsson, Scott R. Justice, Aristotele Hadjichristos
  • Patent number: 6078219
    Abstract: A wide range single stage variable gain amplifier is provided for receiving an input signal and outputting an amplitude varied version of the received input signal. In its most basic form, the wide range single stage variable gain amplifier includes an input circuit receiving an input signal and developing an input current, a first control circuit receiving the input current, the first control circuit being selectively controllable to output an attenuated version of the received input current, a second control circuit directly connected to the first control circuit for receiving the attenuated input current therefrom, the second control circuit being selectively controllable to output a further attenuated version of the attenuated input current, and an output circuit receiving the further attenuated input current and developing an amplitude varied version of the received input signal.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: June 20, 2000
    Assignee: Ericsson Inc.
    Inventors: Aristotele Hadjichristos, Scott R. Justice