Patents by Inventor Sreekiran Samala

Sreekiran Samala 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: 20240175977
    Abstract: A device, e.g., a radar transceiver, includes a receiver and a transmitter. One such device includes a phase shifter having a first input to receive an oscillating signal and a second input to receive a control signal. The device also includes a signal generator having a quadrature (Q) channel output to output a quadrature phase version of the oscillating signal; and a Q channel mixer having an input coupled to the Q channel output. A feedback path of the device includes a filter having an output and an input coupled to an output of the Q channel mixer, and an integrator having an input coupled to the output of the filter. The integrator has an output coupled to the second input of the phase shifter, in which the integrator outputs the control signal to the phase shifter.
    Type: Application
    Filed: February 6, 2024
    Publication date: May 30, 2024
    Inventors: Sreekiran SAMALA, Venkatesh SRINIVASAN, Vijaya B. RENTALA
  • Patent number: 11947031
    Abstract: A radar transceiver includes a receiver. The receiver includes a low noise amplifier a mixer, a baseband filter, an integrator, and a phase shifter. The mixer includes an input coupled to an output of the low noise amplifier. The baseband filter includes an input coupled to an output of the mixer. The integrator includes an input coupled to an output of the baseband filter. The phase shifter includes a control input and an output. The control input is coupled to an output of the integrator.
    Type: Grant
    Filed: November 12, 2019
    Date of Patent: April 2, 2024
    Assignee: Texas Instruments Incorporated
    Inventors: Sreekiran Samala, Venkatesh Srinivasan, Vijaya B. Rentala
  • Patent number: 11789137
    Abstract: In described examples, a frequency modulated continuous wave (FMCW) synthesizer includes a control engine, and a phase locked loop (PLL) including a frequency divider, a control voltage generator (CVG), and a voltage controlled oscillator (VCO). The frequency divider modifies a VCO output frequency based on a control input. The CVG generates a control voltage based on a frequency reference and the frequency divider output. The VCO outputs a FMCW output having the VCO output frequency in response to the control voltage. The control engine generates the control input so that the VCO output frequency: from a first time to a second time, is a first frequency; from the second time to a third time, changes at a first rate; from the third time to a fourth time, changes at a second rate different from the first rate; and from the fourth time to a fifth time, is a second frequency.
    Type: Grant
    Filed: December 30, 2020
    Date of Patent: October 17, 2023
    Assignee: Texas Instruments Incorporated
    Inventors: Karthik Subburaj, Sreekiran Samala, Indu Prathapan
  • Patent number: 11747436
    Abstract: A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.
    Type: Grant
    Filed: September 15, 2020
    Date of Patent: September 5, 2023
    Assignee: Texas Instruments Incorporated
    Inventors: Karthik Subburaj, Karthik Ramasubramanian, Sriram Murali, Sreekiran Samala, Krishnanshu Dandu
  • Patent number: 11486916
    Abstract: A method of frequency estimation. A clock output from a frequency synthesizer is received at an input of a ring encoder. The ring encoder generates outputs including a ring encoder output clock and an encoded output which represents LSBs of a clock cycle count of the clock output. A binary counter is run using the ring encoder output clock which provides an output count which represents MSBs of the clock cycle count. Using a reference clock, the encoded output is sampled to provide a sampled encoded output and the output count is sampled to provide a sampled output count. Error correcting is applied to the sampled encoded output to provide a corrected sampled encoded output. The corrected sampled encoded output and sampled output count are combined to provide a combined output which is used for estimating an instantaneous or average frequency of the clock output.
    Type: Grant
    Filed: November 1, 2021
    Date of Patent: November 1, 2022
    Assignee: Texas Instmments Incorporated
    Inventors: Tom Altus, Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Publication number: 20220206133
    Abstract: In described examples, a frequency modulated continuous wave (FMCW) synthesizer includes a control engine, and a phase locked loop (PLL) including a frequency divider, a control voltage generator (CVG), and a voltage controlled oscillator (VCO). The frequency divider modifies a VCO output frequency based on a control input. The CVG generates a control voltage based on a frequency reference and the frequency divider output. The VCO outputs a FMCW output having the VCO output frequency in response to the control voltage. The control engine generates the control input so that the VCO output frequency: from a first time to a second time, is a first frequency; from the second time to a third time, changes at a first rate; from the third time to a fourth time, changes at a second rate different from the first rate; and from the fourth time to a fifth time, is a second frequency.
    Type: Application
    Filed: December 30, 2020
    Publication date: June 30, 2022
    Inventors: Karthik Subburaj, Sreekiran Samala, Indu Prathapan
  • Publication number: 20220050131
    Abstract: A method of frequency estimation. A clock output from a frequency synthesizer is received at an input of a ring encoder. The ring encoder generates outputs including a ring encoder output clock and an encoded output which represents LSBs of a clock cycle count of the clock output. A binary counter is run using the ring encoder output clock which provides an output count which represents MSBs of the clock cycle count. Using a reference clock, the encoded output is sampled to provide a sampled encoded output and the output count is sampled to provide a sampled output count. Error correcting is applied to the sampled encoded output to provide a corrected sampled encoded output. The corrected sampled encoded output and sampled output count are combined to provide a combined output which is used for estimating an instantaneous or average frequency of the clock output.
    Type: Application
    Filed: November 1, 2021
    Publication date: February 17, 2022
    Inventors: Tom Altus, Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Publication number: 20210356557
    Abstract: A radar transceiver includes a receiver. The receiver includes a low noise amplifier a mixer, a baseband filter, an integrator, and a phase shifter. The mixer includes an input coupled to an output of the low noise amplifier. The baseband filter includes an input coupled to an output of the mixer. The integrator includes an input coupled to an output of the baseband filter. The phase shifter includes a control input and an output. The control input is coupled to an output of the integrator.
    Type: Application
    Filed: November 12, 2019
    Publication date: November 18, 2021
    Inventors: Sreekiran SAMALA, Venkatesh SRINIVASAN, Vijaya B. RENTALA
  • Patent number: 11162986
    Abstract: A method of frequency estimation. A clock output from a frequency synthesizer is received at an input of a ring encoder. The ring encoder generates outputs including a ring encoder output clock and an encoded output which represents LSBs of a clock cycle count of the clock output. A binary counter is run using the ring encoder output clock which provides an output count which represents MSBs of the clock cycle count. Using a reference clock, the encoded output is sampled to provide a sampled encoded output and the output count is sampled to provide a sampled output count. Error correcting is applied to the sampled encoded output to provide a corrected sampled encoded output. The corrected sampled encoded output and sampled output count are combined to provide a combined output which is used for estimating an instantaneous or average frequency of the clock output.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: November 2, 2021
    Assignee: Texas Instruments Incorporated
    Inventors: Tom Altus, Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Publication number: 20210011118
    Abstract: A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.
    Type: Application
    Filed: September 15, 2020
    Publication date: January 14, 2021
    Inventors: Karthik Subburaj, Karthik Ramasubramanian, Sriram Murali, Sreekiran Samala, Krishnanshu Dandu
  • Patent number: 10809353
    Abstract: A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.
    Type: Grant
    Filed: August 28, 2018
    Date of Patent: October 20, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Karthik Ramasubramanian, Sriram Murali, Sreekiran Samala, Krishnanshu Dandu
  • Patent number: 10746851
    Abstract: A testing device for FMCW radar includes an input for receiving a chirp signal generated by the radar. An IQ down-converter coupled to the input down-converts the chirp signal. A digitizer extracts digitized IQ signals from the down-converted chirp signal. A processor coupled to the digitizer determines at least one of frequency linearity and phase noise of the chirp signal.
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: August 18, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Anjan Prasad Eswaran, Shankar Ram Narayanamoorthy, Sreekiran Samala, Karthik Subburaj
  • Publication number: 20200041551
    Abstract: A method of frequency estimation. A clock output from a frequency synthesizer is received at an input of a ring encoder. The ring encoder generates outputs including a ring encoder output clock and an encoded output which represents LSBs of a clock cycle count of the clock output. A binary counter is run using the ring encoder output clock which provides an output count which represents MSBs of the clock cycle count. Using a reference clock, the encoded output is sampled to provide a sampled encoded output and the output count is sampled to provide a sampled output count. Error correcting is applied to the sampled encoded output to provide a corrected sampled encoded output. The corrected sampled encoded output and sampled output count are combined to provide a combined output which is used for estimating an instantaneous or average frequency of the clock output.
    Type: Application
    Filed: October 9, 2019
    Publication date: February 6, 2020
    Inventors: Tom Altus, Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Publication number: 20200025871
    Abstract: A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.
    Type: Application
    Filed: August 28, 2018
    Publication date: January 23, 2020
    Inventors: Karthik Subburaj, Karthik Ramasubramanian, Sriram Murali, Sreekiran Samala, Krishnanshu Dandu
  • Patent number: 10481187
    Abstract: A method of frequency estimation. A clock output from a frequency synthesizer is received at an input of a ring encoder. The ring encoder generates outputs including a ring encoder output clock and an encoded output which represents LSBs of a clock cycle count of the clock output. A binary counter is run using the ring encoder output clock which provides an output count which represents MSBs of the clock cycle count. Using a reference clock, the encoded output is sampled to provide a sampled encoded output and the output count is sampled to provide a sampled output count. Error correcting is applied to the sampled encoded output to provide a corrected sampled encoded output. The corrected sampled encoded output and sampled output count are combined to provide a combined output which is used for estimating an instantaneous or average frequency of the clock output.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: November 19, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Tom Altus, Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Patent number: 10101438
    Abstract: A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: October 16, 2018
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Karthik Ramasubramanian, Sriram Murali, Sreekiran Samala, Krishnanshu Dandu
  • Publication number: 20180074168
    Abstract: A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.
    Type: Application
    Filed: April 15, 2015
    Publication date: March 15, 2018
    Inventors: Karthik Subburaj, Karthik Ramasubramanian, Sriram Murali, Sreekiran Samala, Krishnanshu Dandu
  • Patent number: 9696359
    Abstract: A method of measuring phase noise (PN). A PLL frequency synthesizer is provided including a first phase frequency detector (PFD) receiving a reference frequency signal coupled to a first charge pump (CP) coupled to a VCO having an output fedback to the first PFD through a feedback divider that provides a divided frequency signal to the first PFD which outputs an error signal, and PN measurement circuitry including a replica CP coupled to an output of a second PFD or the first PFD. The error signal is received at the replica CP or the divided and reference frequency signal are received at the second PFD, wherein the replica CP outputs a scaled phase error current which is current-to-voltage converted and amplified to provide an amplified phase error voltage, and digitized to provide a digital phase error signal. The digital phase error signal is frequency analyzed to generate a PN measurement.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: July 4, 2017
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Patent number: RE48613
    Abstract: A method of measuring phase noise (PN). A PLL frequency synthesizer is provided including a first phase frequency detector (PFD) receiving a reference frequency signal coupled to a first charge pump (CP) coupled to a VCO having an output fedback to the first PFD through a feedback divider that provides a divided frequency signal to the first PFD which outputs an error signal, and PN measurement circuitry including a replica CP coupled to an output of a second PFD or the first PFD. The error signal is received at the replica CP or the divided and reference frequency signal are received at the second PFD, wherein the replica CP outputs a scaled phase error current which is current-to-voltage converted and amplified to provide an amplified phase error voltage, and digitized to provide a digital phase error signal. The digital phase error signal is frequency analyzed to generate a PN measurement.
    Type: Grant
    Filed: July 3, 2019
    Date of Patent: June 29, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Sreekiran Samala, Raghu Ganesan
  • Patent number: RE49571
    Abstract: A method of measuring phase noise (PN). A PLL frequency synthesizer is provided including a first phase frequency detector (PFD) receiving a reference frequency signal coupled to a first charge pump (CP) coupled to a VCO having an output fedback to the first PFD through a feedback divider that provides a divided frequency signal to the first PFD which outputs an error signal, and PN measurement circuitry including a replica CP coupled to an output of a second PFD or the first PFD. The error signal is received at the replica CP or the divided and reference frequency signal are received at the second PFD, wherein the replica CP outputs a scaled phase error current which is current-to-voltage converted and amplified to provide an amplified phase error voltage, and digitized to provide a digital phase error signal. The digital phase error signal is frequency analyzed to generate a PN measurement.
    Type: Grant
    Filed: January 21, 2021
    Date of Patent: July 4, 2023
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Sreekiran Samala, Raghu Ganesan