Patents by Inventor Gurusubrahmaniyan Subrahmaniyan Radhakrishnan

Gurusubrahmaniyan Subrahmaniyan Radhakrishnan 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).

  • Publication number: 20230361889
    Abstract: A radio frequency device includes antennas, transmitters, power detectors, a memory storing instructions and an antenna gain lookup table, and processors. The processors execute instructions that include instructing the transmitters to send transmission signals through the antennas to form a first beamformed signal having a first beam direction and a first frequency using multiple input powers. The instructions include determining radio frequency integrated circuit (RFIC) gains associated with the transmitters based on the transmission signals using the power detectors. Moreover, the instructions include determining the antenna gains for the antennas based on the first beam direction and the first frequency of the first beamformed signal, and the antenna gain lookup table. The instructions also include determining total gains based on the RFIC gains and the antenna gains, and adjusting the input powers based on the total gains and a back off power signal.
    Type: Application
    Filed: July 21, 2023
    Publication date: November 9, 2023
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Srinivasa Yasasvy Sateesh Bhamidipati, Daphne Irene Gorman, Vineet Nayak, Xuefeng Zhao
  • Patent number: 11722230
    Abstract: A radio frequency device includes antennas, transmitters, power detectors, a memory storing instructions and an antenna gain lookup table, and processors. The processors execute instructions that include instructing the transmitters to send transmission signals through the antennas to form a first beamformed signal having a first beam direction and a first frequency using multiple input powers. The instructions include determining radio frequency integrated circuit (RFIC) gains associated with the transmitters based on the transmission signals using the power detectors. Moreover, the instructions include determining the antenna gains for the antennas based on the first beam direction and the first frequency of the first beamformed signal, and the antenna gain lookup table. The instructions also include determining total gains based on the RFIC gains and the antenna gains, and adjusting the input powers based on the total gains and a back off power signal.
    Type: Grant
    Filed: October 8, 2020
    Date of Patent: August 8, 2023
    Assignee: Apple Inc.
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Srinivasa Yasasvy Sateesh Bhamidipati, Daphne Irene Gorman, Vineet Nayak, Xuefeng Zhao
  • Publication number: 20220045772
    Abstract: A radio frequency device includes antennas, transmitters, power detectors, a memory storing instructions and an antenna gain lookup table, and processors. The processors execute instructions that include instructing the transmitters to send transmission signals through the antennas to form a first beamformed signal having a first beam direction and a first frequency using multiple input powers. The instructions include determining radio frequency integrated circuit (RFIC) gains associated with the transmitters based on the transmission signals using the power detectors. Moreover, the instructions include determining the antenna gains for the antennas based on the first beam direction and the first frequency of the first beamformed signal, and the antenna gain lookup table. The instructions also include determining total gains based on the RFIC gains and the antenna gains, and adjusting the input powers based on the total gains and a back off power signal.
    Type: Application
    Filed: October 8, 2020
    Publication date: February 10, 2022
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Srinivasa Yasasvy Sateesh Bhamidipati, Daphne Irene Gorman, Vineet Nayak, Xuefeng Zhao
  • Patent number: 10778345
    Abstract: The representative embodiments discussed in the present disclosure relate to techniques in which the operating characteristics (e.g., gain and/or efficiency) of a power amplifier in a transmitter may be regulated according to an operation mode of the transmitter. More specifically, in some embodiments, different look-up tables (LUTs) may be employed for each mode of operation to suitably adjust the supply voltage to the power amplifier and modulate its operating characteristics based on power input to the power amplifier. Further, in some embodiments, a method to calibrate a LUT for uplink carrier aggregation (ULCA) operation mode of the transmitter may be employed to populate a LUT used to suitably adjust the supply voltage during ULCA.
    Type: Grant
    Filed: January 4, 2018
    Date of Patent: September 15, 2020
    Assignee: Apple, Inc.
    Inventors: Wassim El-Hassan, Mohammad Reza Ghajar, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Vineet Nayak, Srinivasa Yasasvy Sateesh Bhamidipati
  • Patent number: 10454423
    Abstract: The representative embodiments discussed in the present disclosure relate to techniques in which the operating characteristics (e.g., power consumption) of a power amplifier in a transceiver may be regulated according to an operation mode of the transceiver. More specifically, in some embodiments, different LUTs may be employed for each mode of operation to suitably adjust the supply voltage (e.g., bias voltage) and/or quiescent current input to the power amplifier based on an input signal and a margin by which transmission standards are met. Further, in some embodiments, a method to calibrate a LUT for average power tracking and/or envelope tracking in a transceiver mode of operation may be employed to populate a LUT that may be used to suitably adjust the power and/or current consumption of the power amplifier.
    Type: Grant
    Filed: April 12, 2018
    Date of Patent: October 22, 2019
    Assignee: APPLE INC.
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Vineet Nayak, Srinivasa Yasasvy Sateesh Bhamidipati, Jaydeep Vijay Ranade
  • Publication number: 20190319583
    Abstract: The representative embodiments discussed in the present disclosure relate to techniques in which the operating characteristics (e.g., power consumption) of a power amplifier in a transceiver may be regulated according to an operation mode of the transceiver. More specifically, in some embodiments, different LUTs may be employed for each mode of operation to suitably adjust the supply voltage (e.g., bias voltage) and/or quiescent current input to the power amplifier based on an input signal and a margin by which transmission standards are met. Further, in some embodiments, a method to calibrate a LUT for average power tracking and/or envelope tracking in a transceiver mode of operation may be employed to populate a LUT that may be used to suitably adjust the power and/or current consumption of the power amplifier.
    Type: Application
    Filed: April 12, 2018
    Publication date: October 17, 2019
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Vineet Nayak, Srinivasa Yasasvy Sateesh Bhamidipati, Jaydeep Vijay Ranade
  • Publication number: 20190081712
    Abstract: The representative embodiments discussed in the present disclosure relate to techniques in which the operating characteristics (e.g., gain and/or efficiency) of a power amplifier in a transmitter may be regulated according to an operation mode of the transmitter. More specifically, in some embodiments, different LUTs may be employed for each mode of operation to suitably adjust the supply voltage to the power amplifier and modulate its operating characteristics based on power input to the power amplifier. Further, in some embodiments, a method to calibrate a LUT for ULCA, an operation mode of the transmitter, may be employed to populate a LUT that may be used to suitably adjust the supply voltage during ULCA.
    Type: Application
    Filed: January 4, 2018
    Publication date: March 14, 2019
    Inventors: Wassim El-Hassan, Mohammad Reza Ghajar, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Vineet Nayak, Srinivasa Yasasvy Sateesh Bhamidipati
  • Patent number: 9654154
    Abstract: Systems and method for improving operation of a radio frequency system are provided. One embodiment includes instructions to execute a coarse calibration to associate a first output power with a first operational parameter set; instruct the radio frequency system to transmit a signal based at least in part on the first operational parameter set and a base detrough function; determine performance metrics resulting from transmission of the signal; determine changes in the performance metrics resulting from operating the radio frequency based at least in part on the first operational parameter set and each of a plurality of augmented detrough functions; and associate a second operational parameter set with a second output power, in which the second operational parameter set includes one of the plurality of augmented detrough functions selected based at least in part on the changes that reduce margin between the performance metrics and performance metric thresholds.
    Type: Grant
    Filed: July 8, 2015
    Date of Patent: May 16, 2017
    Assignee: APPLE INC.
    Inventors: Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Wassim El-Hassan
  • Publication number: 20170126258
    Abstract: An electronic device may include wireless communications circuitry that has first and second digital predistortion circuits. The first predistortion circuit receives a first signal at a first frequency while the second predistortion circuit receives a second signal at a second frequency. The first circuit may perform predistortion operations on the first signal using non-unity predistortion coefficients to generate a predistorted signal. The second circuit may apply unity predistortion coefficients to the second signal to generate an undistorted signal. An adder may combine the predistorted and undistorted signals to generate a combined signal that is amplified by amplifier circuitry. An antenna may transmit the amplified signal.
    Type: Application
    Filed: September 19, 2016
    Publication date: May 4, 2017
    Inventors: Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Wassim El-Hassan, Srinivasa Yasasvy Sateesh Bhamidipati, Hailong Yang
  • Patent number: 9634695
    Abstract: An electronic device may include wireless communications circuitry that has first and second digital predistortion circuits. The first predistortion circuit receives a first signal at a first frequency while the second predistortion circuit receives a second signal at a second frequency. The first circuit may perform predistortion operations on the first signal using non-unity predistortion coefficients to generate a predistorted signal. The second circuit may apply unity predistortion coefficients to the second signal to generate an undistorted signal. An adder may combine the predistorted and undistorted signals to generate a combined signal that is amplified by amplifier circuitry. An antenna may transmit the amplified signal.
    Type: Grant
    Filed: September 19, 2016
    Date of Patent: April 25, 2017
    Assignee: Apple Inc.
    Inventors: Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Wassim El-Hassan, Srinivasa Yasasvy Sateesh Bhamidipati, Hailong Yang
  • Patent number: 9537519
    Abstract: Wireless communications circuitry in an electronic device may include power amplifier circuitry that is powered using a bias voltage supplied by adjustable power supply circuitry. The power supply circuitry may include envelope tracking circuitry that continuously adjusts the bias voltage. The wireless communications circuitry may generate test signals and may generate performance metric data from the test signals. Processing circuitry may generate bias voltage calibration data based on the performance metric data and may provide the calibration data to the envelope tracking circuitry. After the calibration data has been generated, the envelope tracking circuitry may continuously select bias voltages to provide to the amplifier based on the magnitude of signals that are transmitted and the calibration data. By actively adjusting the bias voltage in this way, power consumption may be minimized without generating undesirable harmonics or other radio-frequency performance requirement violations.
    Type: Grant
    Filed: October 27, 2014
    Date of Patent: January 3, 2017
    Assignee: Apple Inc.
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan
  • Patent number: 9300333
    Abstract: Methods for performing predistortion calibration on wireless communications circuitry are provided. The wireless communications circuitry may be adjusted using a digital gain setting and a radio gain index setting. A particular channel in a given band exhibiting the maximum dynamic range may be selected for measurement. Predistortion coefficient values may be computed based on measured results in the select channel. A power list may be obtained for the selected channel based on a maximum peak power level. A reference power list may then be obtained based on the minimum dynamic range in the given band. The predistortion coefficients associated with the selected channel may be translated from its power list to the reference power list. Predistortion coefficients for the remaining channels in the given band may similarly be computed by interpolating/extrapolating based on the values in their respective power lists and the reference power list.
    Type: Grant
    Filed: August 1, 2014
    Date of Patent: March 29, 2016
    Assignee: Apple Inc.
    Inventor: Gurusubrahmaniyan Subrahmaniyan Radhakrishnan
  • Publication number: 20160072457
    Abstract: Systems and method for improving operation of a radio frequency system are provided. One embodiment includes instructions to execute a coarse calibration to associate a first output power with a first operational parameter set; instruct the radio frequency system to transmit a signal based at least in part on the first operational parameter set and a base detrough function; determine performance metrics resulting from transmission of the signal; determine changes in the performance metrics resulting from operating the radio frequency based at least in part on the first operational parameter set and each of a plurality of augmented detrough functions; and associate a second operational parameter set with a second output power, in which the second operational parameter set includes one of the plurality of augmented detrough functions selected based at least in part on the changes that reduce margin between the performance metrics and performance metric thresholds.
    Type: Application
    Filed: July 8, 2015
    Publication date: March 10, 2016
    Inventors: Gurusubrahmaniyan Subrahmaniyan Radhakrishnan, Wassim El-Hassan
  • Publication number: 20160072530
    Abstract: Wireless communications circuitry in an electronic device may include power amplifier circuitry that is powered using a bias voltage supplied by adjustable power supply circuitry. The power supply circuitry may include envelope tracking circuitry that continuously adjusts the bias voltage. The wireless communications circuitry may generate test signals and may generate performance metric data from the test signals. Processing circuitry may generate bias voltage calibration data based on the performance metric data and may provide the calibration data to the envelope tracking circuitry. After the calibration data has been generated, the envelope tracking circuitry may continuously select bias voltages to provide to the amplifier based on the magnitude of signals that are transmitted and the calibration data. By actively adjusting the bias voltage in this way, power consumption may be minimized without generating undesirable harmonics or other radio-frequency performance requirement violations.
    Type: Application
    Filed: October 27, 2014
    Publication date: March 10, 2016
    Inventors: Wassim El-Hassan, Gurusubrahmaniyan Subrahmaniyan Radhakrishnan
  • Publication number: 20160036471
    Abstract: Methods for performing predistortion calibration on wireless communications circuitry are provided. The wireless communications circuitry may be adjusted using a digital gain setting and a radio gain index setting. A particular channel in a given band exhibiting the maximum dynamic range may be selected for measurement. Predistortion coefficient values may be computed based on measured results in the select channel. A power list may be obtained for the selected channel based on a maximum peak power level. A reference power list may then be obtained based on the minimum dynamic range in the given band. The predistortion coefficients associated with the selected channel may be translated from its power list to the reference power list. Predistortion coefficients for the remaining channels in the given band may similarly be computed by interpolating/extrapolating based on the values in their respective power lists and the reference power list.
    Type: Application
    Filed: August 1, 2014
    Publication date: February 4, 2016
    Inventor: Gurusubrahmaniyan Subrahmaniyan Radhakrishnan