Patents by Inventor Sudip Shekhar

Sudip Shekhar 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: 11940386
    Abstract: A sensor architecture that uses fixed wavelength light and tunes a wavelength dependent response of a sensor may be used for detecting analytes in a wide range of applications. The sensor architecture is based on optical resonators or interferometers comprising optical waveguides. A resonance wavelength and/or transmission/reflection spectrum are affected by presence of an analyte adsorbed on a surface of the waveguide, and a setting of a phase modulator. The sensors include a sensor portion where part of the waveguide is exposed to a sample for sensing, and a phase modulator part. The phase modulator part may include a heater that is controlled to tune, or sweep, or modulate the resonant wavelength and/or spectrum of the sensor.
    Type: Grant
    Filed: September 6, 2022
    Date of Patent: March 26, 2024
    Assignee: The University of British Columbia
    Inventors: Lukas Chrostowski, Sudip Shekhar, Samantha Grist, Karen C. Cheung, Mohammed Ali Al-Qadasi
  • Publication number: 20230093490
    Abstract: A “frequency shifter” is a clock synthesis system, that includes either a multiplexer or a multi-modulus divider (MMD), a fractional frequency divider, a tunable delay element, a sawtooth signal generator, in addition to other synchronization and control circuits. The generated sawtooth signal is used to control the delay of the tunable delay element, which in turn is used to adjust the phase of the signal generated by either M-to-1 multiplexer or the MMD, reducing its timing errors, and improving the spectral purity of the generated clock signal.
    Type: Application
    Filed: February 23, 2021
    Publication date: March 23, 2023
    Inventors: Ahmad Sharkia, Sudip Shekhar, Shahriar Mirabbasi
  • Publication number: 20230081317
    Abstract: A sensor architecture that uses fixed wavelength light and tunes a wavelength dependent response of a sensor may be used for detecting analytes in a wide range of applications. The sensor architecture is based on optical resonators or interferometers comprising optical waveguides. A resonance wavelength and/or transmission/reflection spectrum are affected by presence of an analyte adsorbed on a surface of the waveguide, and a setting of a phase modulator. The sensors include a sensor portion where part of the waveguide is exposed to a sample for sensing, and a phase modulator part. The phase modulator part may include a heater that is controlled to tune, or sweep, or modulate the resonant wavelength and/or spectrum of the sensor.
    Type: Application
    Filed: September 6, 2022
    Publication date: March 16, 2023
    Inventors: Lukas CHROSTOWSKI, Sudip SHEKHAR, Samantha GRIST, Karen C. CHEUNG, Mohammed Ali AL-QADASI
  • Publication number: 20220102863
    Abstract: An electromagnetic wave manipulation apparatus may include a substrate integrated with a liquid crystal. For example, the substrate may include one or more cavities filled with the liquid crystal. Alternatively and/or additionally, the substrate may include one or more layers of material interposed with the liquid crystal. The liquid crystal may be subjected to a voltage bias that alters the dielectric constant of the liquid crystal. Doing so may introduce a corresponding field offset between the input signal and the output signal of the apparatus. Subjecting the liquid crystal to different voltage biases may give rise to a spatial phase gradient that enables the apparatus to perform a variety of electromagnetic wave transformations such as reflection, refraction, retro-reflection, amplification, and cancellation. By performing such transformations, the apparatus may change the radiation pattern of its output signal, thus steering its output signal towards or away from a receiver.
    Type: Application
    Filed: September 29, 2021
    Publication date: March 31, 2022
    Inventors: Sudip Shekhar, Md Nazmul Hasan, Dinesh Bharadia
  • Publication number: 20210313757
    Abstract: Methods, circuits, and techniques for reflection cancellation. Laser output is tapped. A tapped portion of the laser output is phase shifted to generate a feedback signal, with the feedback signal being out-of-phase with a parasitic reflection of the laser output. The feedback signal is directed towards the laser such that the parasitic reflection and feedback signal are superpositioned before entering the laser. A magnitude and a phase of the feedback signal are such that superposition of the feedback signal and the parasitic reflection results in a resulting signal of lower magnitude than the parasitic reflection alone. During laser operation, a magnitude of the resulting signal is monitored and, as the parasitic reflection varies, the magnitude of the resulting signal is adjusted by adjusting at least one of the magnitude and the phase of the feedback signal in response to the monitoring of the resulting signal.
    Type: Application
    Filed: June 18, 2021
    Publication date: October 7, 2021
    Inventors: Lukas Chrostowski, Nicolas A.F. Jaeger, Sudip Shekhar, Hasitha Jayatilleka, Hossam A.S. Shoman
  • Publication number: 20210050878
    Abstract: An electronic circuit for generating a delayed radio signal for use in a radio communication device configured to provide a transmit baseband signal in a baseband, to up-convert the transmit baseband signal into a transmit radio signal in a radio band, to transmit the transmit radio signal in the radio band, and to simultaneously receive a receive radio signal in the same radio band, is provided. The electronic circuit may include an input circuit, a delay circuit, a down-converting circuit, an up-converting circuit, and an output circuit.
    Type: Application
    Filed: June 4, 2020
    Publication date: February 18, 2021
    Inventors: Sudip Shekhar, Ahmed El Sayed
  • Patent number: 10804988
    Abstract: A discrete-time delay (TD) technique in a baseband receiver array is disclosed for canceling wide modulated bandwidth spatial interference and reducing the Analog-to-Digital Conversion (ADC) dynamic range requirements. In particular, the discrete-time delay (TD) technique first aligns the interference using non-uniform sampled phases followed by uniform cancellation using a cancellation matrix, such as, for example, a Truncated Hadamard Transform implemented with antipodal binary coefficients.
    Type: Grant
    Filed: September 9, 2019
    Date of Patent: October 13, 2020
    Assignees: Washington State University, The University of British Columbia
    Inventors: Subhanshu Gupta, Erfan Ghaderi, Sudip Shekhar, Shyam Venkatasubramanian, Ajith Sivadhasan Ramani
  • Patent number: 10680673
    Abstract: An electronic circuit for generating a delayed radio signal for use in a radio communication device configured to provide a transmit baseband signal in a baseband, to up-convert the transmit baseband signal into a transmit radio signal in a radio band, to transmit the transmit radio signal in the radio band, and to simultaneously receive a receive radio signal in the same radio band, is provided. The electronic circuit may include a delay circuit configured to delay a copy of the transmit baseband signal by an amount of time to generate a delayed baseband signal, an up-converting circuit configured to shift the frequency spectrum of the delayed baseband signal to the radio band to generate a delayed radio signal, and an output circuit configured to output the delayed radio signal for a cancellation circuit to cancel the delayed radio signal from the receive radio signal.
    Type: Grant
    Filed: December 24, 2015
    Date of Patent: June 9, 2020
    Assignee: INTEL CORPORATION
    Inventors: Sudip Shekhar, Ahmed El Sayed
  • Publication number: 20200083936
    Abstract: A discrete-time delay (TD) technique in a baseband receiver array is disclosed for canceling wide modulated bandwidth spatial interference and reducing the Analog-to-Digital Conversion (ADC) dynamic range requirements. In particular, the discrete-time delay (TD) technique first aligns the interference using non-uniform sampled phases followed by uniform cancellation using a cancellation matrix, such as, for example, a Truncated Hadamard Transform implemented with antipodal binary coefficients.
    Type: Application
    Filed: September 9, 2019
    Publication date: March 12, 2020
    Inventors: Subhanshu Gupta, Erfan Ghaderi, Sudip Shekhar, Shyam Venkatasubramanian, Ajith Sivadhasan Ramani
  • Patent number: 10347309
    Abstract: Embodiments include a resistor, coupled on a signal path, that includes one or more resistive memory elements, such as one or more magnetic tunnel junctions (MTJs). The resistance of the resistive memory elements may be digitally trimmable to adjust a resistance of the resistor on the signal path. The resistor may be incorporated into an analog or mixed signal circuit to pass an analog signal on the signal path. Other embodiments may be described and claimed.
    Type: Grant
    Filed: February 22, 2017
    Date of Patent: July 9, 2019
    Assignee: Intel Corporation
    Inventors: Jaydeep P. Kulkarni, Ashoke Ravi, Dinesh Somasekhar, Ganesh Balamurugan, Sudip Shekhar, Tawfiq Musah, Tzu-Chien Hsueh
  • Patent number: 10209537
    Abstract: A method and apparatus for monitoring and feedback control of a photonic switch such as 2×2 Mach-Zehnder Interferometer switch. Optical signals at an input and an output of the switch are monitored via optical taps. A sinusoidal time-varying phase shift is applied to one of the monitoring signals. An optical combiner then combines the monitoring signals. A photodetector monitors output of the optical combiner to provide a feedback signal. The amplitude of the feedback signal due to the time-varying phase shift increases with the amount of input signal present in the output signal. When the input signal is to be routed to the output (e.g. for a bar state), a controller manipulates the switch to maximize feedback signal amplitude. When the input signal is to be routed to a different output (e.g. for a cross state), the controller manipulates the switch to minimize feedback signal amplitude.
    Type: Grant
    Filed: September 9, 2016
    Date of Patent: February 19, 2019
    Assignee: Huawei Technologies Canada Co., Ltd.
    Inventors: Ray Chung, Zeqin Lu, Hasitha Jayatilleka, Mohammed Wadah Al Taha, Sudip Shekhar, Shahriar Mirabbasi, Lukas Chrostowski
  • Publication number: 20180358997
    Abstract: An electronic circuit for generating a delayed radio signal for use in a radio communication device configured to provide a transmit baseband signal in a baseband, to up-convert the transmit baseband signal into a transmit radio signal in a radio band, to transmit the transmit radio signal in the radio band, and to simultaneously receive a receive radio signal in the same radio band, is provided. The electronic circuit may include a delay circuit configured to delay a copy of the transmit baseband signal by an amount of time to generate a delayed baseband signal, an up-converting circuit configured to shift the frequency spectrum of the delayed baseband signal to the radio band to generate a delayed radio signal, and an output circuit configured to output the delayed radio signal for a cancellation circuit to cancel the delayed radio signal from the receive radio signal.
    Type: Application
    Filed: December 24, 2015
    Publication date: December 13, 2018
    Inventors: Sudip Shekhar, Ahmed El Sayed
  • Publication number: 20180074386
    Abstract: A method and apparatus for monitoring and feedback control of a photonic switch such as 2×2 Mach-Zehnder Interferometer switch. Optical signals at an input and an output of the switch are monitored via optical taps. A sinusoidal time-varying phase shift is applied to one of the monitoring signals. An optical combiner then combines the monitoring signals. A photodetector monitors output of the optical combiner to provide a feedback signal. The amplitude of the feedback signal due to the time-varying phase shift increases with the amount of input signal present in the output signal. When the input signal is to be routed to the output (e.g. for a bar state), a controller manipulates the switch to maximize feedback signal amplitude. When the input signal is to be routed to a different output (e.g. for a cross state), the controller manipulates the switch to minimize feedback signal amplitude.
    Type: Application
    Filed: September 9, 2016
    Publication date: March 15, 2018
    Applicant: Huawei Technologies Canada Co., Ltd.
    Inventors: Ray CHUNG, Zeqin LU, Hasitha JAYATILLEKA, Mohammed Wadah ALTAHA, Sudip SHEKHAR, Shahriar MIRABBASI, Lukas CHROSTOWSKI
  • Publication number: 20170315424
    Abstract: A temperature compensated carrier effect switching cell controls phase shifts to compensate for phase errors induced by temperature difference between arms of the switching cell. The temperature difference may be generated by driving the carrier effect region of the switching cell. Temperature sensors within the arms of the switching cell provide signals indicative of the temperature difference.
    Type: Application
    Filed: May 2, 2016
    Publication date: November 2, 2017
    Inventors: Dritan Celo, Dominic John Goodwill, Lukas Chrostowski, Sudip Shekhar
  • Publication number: 20170229161
    Abstract: Embodiments include a resistor, coupled on a signal path, that includes one or more resistive memory elements, such as one or more magnetic tunnel junctions (MTJs). The resistance of the resistive memory elements may be digitally trimmable to adjust a resistance of the resistor on the signal path. The resistor may be incorporated into an analog or mixed signal circuit to pass an analog signal on the signal path. Other embodiments may be described and claimed.
    Type: Application
    Filed: February 22, 2017
    Publication date: August 10, 2017
    Inventors: Jaydeep P. Kulkarni, Ashoke Ravi, Dinesh Somasekhar, Ganesh Balamurugan, Sudip Shekhar, Tawfiq Musah, Tzu-Chien Hsueh
  • Patent number: 9589615
    Abstract: Embodiments include a resistor, coupled on a signal path, that includes one or more resistive memory elements, such as one or more magnetic tunnel junctions (MTJs). The resistance of the resistive memory elements may be digitally trimmable to adjust a resistance of the resistor on the signal path. The resistor may be incorporated into an analog or mixed signal circuit to pass an analog signal on the signal path. Other embodiments may be described and claimed.
    Type: Grant
    Filed: June 25, 2015
    Date of Patent: March 7, 2017
    Assignee: Intel Corporation
    Inventors: Jaydeep P. Kulkarni, Ashoke Ravi, Dinesh Somasekhar, Ganesh Balamurugan, Sudip Shekhar, Tawfiq Musah, Tzu-Chien Hsueh
  • Publication number: 20160379695
    Abstract: Embodiments include a resistor, coupled on a signal path, that includes one or more resistive memory elements, such as one or more magnetic tunnel junctions (Mils). The resistance of the resistive memory elements may be digitally trimmable to adjust a resistance of the resistor on the signal path. The resistor may be incorporated into an analog or mixed signal circuit to pass an analog signal on the signal path. Other embodiments may be described and claimed.
    Type: Application
    Filed: June 25, 2015
    Publication date: December 29, 2016
    Inventors: Jaydeep P. Kulkarni, Ashoke Ravi, Dinesh Somasekhar, Ganesh Balamurugan, Sudip Shekhar, Tawfiq Musah, Tzu-Chien Hsueh
  • Publication number: 20160356959
    Abstract: The disclosure demonstrates n-doped resistive heaters in silicon waveguides showing photoconductive effects with high responsivities on the order of 100 mA/W. These photoconductive heaters, integrated into microring resonator (MRR)-based filters, can be used to automatically tune and stabilize the filters' resonance wavelength to the input laser-wavelength. This is achieved without requiring dedicated defect implantations, additional material depositions, dedicated photodetectors, or optical power tap-outs. Series-coupled higher-order MRR-based filters can be automatically tuned by sequentially aligning the resonance of each MRR to the laser-wavelength by using photoconductive heaters to monitor the light intensity in each MRR. Embodiments allow for the automatic wavelength stabilization of MRR-based optical circuits.
    Type: Application
    Filed: February 2, 2016
    Publication date: December 8, 2016
    Applicant: Huawei Technologies Canada Co., Ltd.
    Inventors: Hasitha JAYATILLEKA, Kyle Jacob MURRAY, Lukas CHROSTOWSKI, Sudip SHEKHAR
  • Patent number: 7683729
    Abstract: In general, in one aspect, the disclosure describes an apparatus that includes an inductive capacitive voltage controlled oscillator (LC VCO) to generate an output clock. A voltage to current converter is used to receive a forwarded clock and to inject the forwarded clock to the LC VCO. The output clock is a deskewed version of the forwarded clock.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: March 23, 2010
    Assignee: Intel Corporation
    Inventors: Mozhgan Mansuri, Sudip Shekhar, Bryan K. Casper, Frank P. O'Mahony
  • Publication number: 20080238503
    Abstract: In general, in one aspect, the disclosure describes an apparatus that includes an inductive capacitive voltage controlled oscillator (LC VCO) to generate an output clock. A voltage to current converter is used to receive a forwarded clock and to inject the forwarded clock to the LC VCO. The output clock is a deskewed version of the forwarded clock.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 2, 2008
    Inventors: Mozhgan Mansuri, Sudip Shekhar, Bryan K. Casper, Frank P. O'Mahony