Patents by Inventor Karthik Subburaj

Karthik Subburaj 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: 10775489
    Abstract: A radar system is provided that includes a radar transceiver integrated circuit (IC) configurable to transmit a first frame of chirps, and another radar transceiver IC configurable to transmit a second frame of chirps at a time delay ?T, wherein ?T=Tc/K, K?2 and Tc is an elapsed time from a start of one chirp in the first frame and the second frame and a start of a next chirp in the first frame and the second frame, wherein the radar system is configured to determine a velocity of an object in a field of view of the radar system based on first digital intermediate frequency signals generated responsive to receiving reflected chirps of the first frame and second digital IF signals generated responsive to receiving reflected chirps of the time delayed second frame, wherein the maximum measurable velocity is increased by a factor of K.
    Type: Grant
    Filed: August 1, 2017
    Date of Patent: September 15, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sandeep Rao, Karthik Subburaj, Sriram Murali, Karthik Ramasubramanian
  • Publication number: 20200284874
    Abstract: A method for a radar system includes transmitting, by a transmit channel of the radar system, a frame comprising first, second, and third chirps. Each chirp has a chirp start frequency, and the chirp start frequency of the transmitted chirps is dithered. The method also includes receiving, by a receive channel of the radar system, a frame of reflected chirps based on the transmitted frame, and generating a digital intermediate frequency (IF) signal.
    Type: Application
    Filed: March 6, 2019
    Publication date: September 10, 2020
    Inventors: Shankar Ram NARAYANA MOORTHY, Karthik SUBBURAJ, Anil KV KUMAR
  • Patent number: 10768278
    Abstract: A FMCW radar system with a built-in self-test (BIST) system for monitoring includes a receiver, a transmitter, and a frequency synthesizer. A FMCW chirp timing engine controls timing of operations at least one radar component. The BIST system includes at least one switchable coupling for coupling a first plurality of different analog signals including from a first plurality of selected nodes in the receiver or transmitter that are all coupled to a second number of monitor analog-to-digital converters (ADCs). The second number is less than (<) the first plurality of different analog signals. The BIST system includes a monitor timing engine and controller operating synchronously with the chirp timing engine, that includes a software configurable monitoring architecture for generating control signals including for selecting using the switchable coupling which analog signal to forward to the monitor ADC and when the monitor ADC samples the analog signals.
    Type: Grant
    Filed: October 25, 2016
    Date of Patent: September 8, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Indu Prathapan, Karthik Ramasubramanian, Brian P. Ginsburg
  • 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: 20200225318
    Abstract: A radar system is provided that includes a receive channel including a complex baseband and a processor coupled to the receive channel to receive a first plurality of digital intermediate frequency (IF) samples from an in-band (I) channel of the complex baseband and a corresponding second plurality of digital IF samples from a quadrature (Q) channel of the complex baseband, wherein the processor is configured to execute instructions to compute at least one failure metric based on the first plurality of digital IF samples and the second plurality of digital IF samples.
    Type: Application
    Filed: March 31, 2020
    Publication date: July 16, 2020
    Inventors: Karthik Ramasubramanian, Karthik Subburaj, Jasbir Singh Nayyar
  • Publication number: 20200209352
    Abstract: In accordance with described examples, a method determines if a velocity of an object detected by a radar is greater than a maximum velocity by receiving on a plurality of receivers at least one frame of chirps transmitted by at least two transmitters and reflected off of the object. A velocity induced phase shift (?d) in a virtual array vector S of signals received by each receiver corresponding to a sequence of chirps (frame) transmitted by each transmitter is estimated. Phases of each element of virtual array vector S are corrected using ?d to generate a corrected virtual array vector Sc. A first Fourier transform is performed on the corrected virtual array vector Sc to generate a corrected virtual array spectrum to detect a signature that indicates that the object has an absolute velocity greater than a maximum velocity.
    Type: Application
    Filed: March 10, 2020
    Publication date: July 2, 2020
    Inventors: Sandeep Rao, Karthik Subburaj, Dan Wang, Adeel Ahmad
  • Publication number: 20200209353
    Abstract: Methods for monitoring of performance parameters of one or more receive channels and/or one or more transmit channels of a radar system-on-a-chip (SOC) are provided. The radar SOC may include a loopback path coupling at least one transmit channel to at least one receive channel to provide a test signal from the at least one transmit channel to the at least one receive channel when the radar SOC is operated in test mode. In some embodiments, the loopback path includes a combiner coupled to each of one or more transmit channels, a splitter coupled to each of one or more receive channels, and a single wire coupling an output of the combiner to an input of the splitter.
    Type: Application
    Filed: March 12, 2020
    Publication date: July 2, 2020
    Inventors: Karthik Subburaj, Brian Paul Ginsburg, Daniel Colum Breen, Sandeep Rao, Karthik Ramasubramanian
  • Patent number: 10659078
    Abstract: A integrated circuit (IC) chip can include a root timer that generates a frame pulse based on a start trigger signal. The IC chip can also include a hardware clock control that provides a clock signal based on a selected one of the frame pulse and the synchronization signal provided from one of the root timer and another IC chip. The IC chip can further include a plurality of analog to digital converters (ADCs). Each of the plurality of ADCs being configured to sample an output of a respective one of a plurality of radio frequency (RF) receivers based on the clock signal.
    Type: Grant
    Filed: November 26, 2018
    Date of Patent: May 19, 2020
    Assignee: TEXAS INTRUMENTS INCORPORATED
    Inventors: Jasbir Singh Nayyar, Brian Ginsburg, Karthik Subburaj
  • Patent number: 10649069
    Abstract: The disclosure provides a radar apparatus for estimating a position and a velocity of the plurality of obstacles. The radar apparatus includes a local oscillator that generates a first signal. A first transmit unit receives the first signal from the local oscillator and generates a first transmit signal. A frequency shifter receives the first signal from the local oscillator and generates a second signal. A second transmit unit receives the second signal and generates a second transmit signal. The frequency shifter provides a frequency offset to the first signal based on a routing delay mismatch to generate the second signal such that the first transmit signal is phase coherent with the second transmit signal.
    Type: Grant
    Filed: June 28, 2017
    Date of Patent: May 12, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Ramasubramanian, Karthik Subburaj, Sachin Bhardwaj
  • Patent number: 10641866
    Abstract: A radar system is provided that includes a receive channel including a complex baseband and a processor coupled to the receive channel to receive a first plurality of digital intermediate frequency (IF) samples from an in-band (I) channel of the complex baseband and a corresponding second plurality of digital IF samples from a quadrature (Q) channel of the complex baseband, wherein the processor is configured to execute instructions to compute at least one failure metric based on the first plurality of digital IF samples and the second plurality of digital IF samples.
    Type: Grant
    Filed: August 5, 2016
    Date of Patent: May 5, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Ramasubramanian, Karthik Subburaj, Jasbir Singh Nayyar
  • Publication number: 20200132810
    Abstract: Methods, apparatus, systems and articles of manufacture to compensate radar system calibration are disclosed. A radio-frequency (RF) subsystem having a transmit channel, a receive channel, and a loopback path comprising at least a portion of the transmit channel and at least a portion of the receive channel, a loopback measurer to measure a first loopback response of the RF subsystem for a first calibration configuration of the RF subsystem, and to measure a second loopback response of the RF subsystem for a second calibration configuration of the RF subsystem, and a compensator to adjust at least one of a transmit programmable shifter or a digital front end based on a difference between the first loopback response and the second loopback response to compensate for a loopback response change when the RF subsystem is changed from the first calibration configuration to the second calibration configuration.
    Type: Application
    Filed: July 16, 2019
    Publication date: April 30, 2020
    Inventors: Karthik Subburaj, Shankar Narayanamoorthy, Karthik Ramasubramanian, Anand Gadiyar, Dheeraj Kumar Shetty, Shailesh Joshi
  • Patent number: 10627483
    Abstract: In accordance with described examples, a method determines if a velocity of an object detected by a radar is greater than a maximum velocity by receiving on a plurality of receivers at least one frame of chirps transmitted by at least two transmitters and reflected off of the object. A velocity induced phase shift (?d) in a virtual array vector S of signals received by each receiver corresponding to a sequence of chirps (frame) transmitted by each transmitter is estimated. Phases of each element of virtual array vector S are corrected using ?d to generate a corrected virtual array vector Sc. A first Fourier transform is performed on the corrected virtual array vector Sc to generate a corrected virtual array spectrum to detect a signature that indicates that the object has an absolute velocity greater than a maximum velocity.
    Type: Grant
    Filed: December 7, 2016
    Date of Patent: April 21, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sandeep Rao, Karthik Subburaj, Dan Wang, Adeel Ahmad
  • Patent number: 10598767
    Abstract: Methods for monitoring of performance parameters of one or more receive channels and/or one or more transmit channels of a radar system-on-a-chip (SOC) are provided. The radar SOC may include a loopback path coupling at least one transmit channel to at least one receive channel to provide a test signal from the at least one transmit channel to the at least one receive channel when the radar SOC is operated in test mode. In some embodiments, the loopback path includes a combiner coupled to each of one or more transmit channels, a splitter coupled to each of one or more receive channels, and a single wire coupling an output of the combiner to an input of the splitter.
    Type: Grant
    Filed: January 22, 2019
    Date of Patent: March 24, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Brian Paul Ginsburg, Daniel Colum Breen, Sandeep Rao, Karthik Ramasubramanian
  • 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: 10429515
    Abstract: A GNSS receiver to track low power GNSS satellite signals. The GNSS receiver includes a frequency locked loop (FLL) that measures a current doppler frequency of the satellite signal. A delay locked loop (DLL) measures a current code phase delay of the satellite signal. A current operating point corresponds to the current doppler frequency and the current code phase delay of the satellite signal. A grid monitor receives the satellite signal and the current operating point, and measures a satellite signal strength at a plurality of predefined offset points from the current operating point. The FLL and the DLL are centered at the current operating point. A peak detector is coupled to the grid monitor and processes the satellite signal strengths at the plurality of predefined offset points and re-centers the FLL and the DLL to a predefined offset point with the satellite signal strength above a predefined threshold.
    Type: Grant
    Filed: June 22, 2017
    Date of Patent: October 1, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Jawaharlal Tangudu, Saurabh Khanna
  • Publication number: 20190154797
    Abstract: Methods for monitoring of performance parameters of one or more receive channels and/or one or more transmit channels of a radar system-on-a-chip (SOC) are provided. The radar SOC may include a loopback path coupling at least one transmit channel to at least one receive channel to provide a test signal from the at least one transmit channel to the at least one receive channel when the radar SOC is operated in test mode. In some embodiments, the loopback path includes a combiner coupled to each of one or more transmit channels, a splitter coupled to each of one or more receive channels, and a single wire coupling an output of the combiner to an input of the splitter.
    Type: Application
    Filed: January 22, 2019
    Publication date: May 23, 2019
    Inventors: Karthik Subburaj, Brian Paul Ginsburg, Daniel Colum Breen, Sandeep Rao, Karthik Ramasubramanian
  • Publication number: 20190097651
    Abstract: A integrated circuit (IC) chip can include a root timer that generates a frame pulse based on a start trigger signal. The IC chip can also include a hardware clock control that provides a clock signal based on a selected one of the frame pulse and the synchronization signal provided from one of the root timer and another IC chip. The IC chip can further include a plurality of analog to digital converters (ADCs). Each of the plurality of ADCs being configured to sample an output of a respective one of a plurality of radio frequency (RF) receivers based on the clock signal.
    Type: Application
    Filed: November 26, 2018
    Publication date: March 28, 2019
    Inventors: Jasbir Singh Nayyar, Brian Ginsburg, KARTHIK SUBBURAJ
  • Patent number: 10234542
    Abstract: Methods for monitoring of performance parameters of one or more receive channels and/or one or more transmit channels of a radar system-on-a-chip (SOC) are provided. The radar SOC may include a loopback path coupling at least one transmit channel to at least one receive channel to provide a test signal from the at least one transmit channel to the at least one receive channel when the radar SOC is operated in test mode. In some embodiments, the loopback path includes a combiner coupled to each of one or more transmit channels, a splitter coupled to each of one or more receive channels, and a single wire coupling an output of the combiner to an input of the splitter.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: March 19, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Subburaj, Brian Paul Ginsburg, Daniel Colum Breen, Sandeep Rao, Karthik Ramasubramanian