Patents by Inventor Ravindranath D. Shrivastava

Ravindranath D. Shrivastava 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: 20240097656
    Abstract: Methods and devices to reduce glitches in phase shifters implementing high isolation switches are disclosed. Such glitches occur at the output of the phase shifters when transitioning from one phase shift to another. The disclosed method implements delays in various steps of the phase shifter transitions. Exemplary embodiments implementing single-pole multi-throw are provided and exemplary performance of the disclosed methods are also presented. The described methods are also applicable to multi-step attenuators.
    Type: Application
    Filed: September 19, 2022
    Publication date: March 21, 2024
    Inventors: Ravindranath D. SHRIVASTAVA, Fleming LAM, Payman SHANJANI
  • Publication number: 20240063789
    Abstract: A FET switch stack and a method to operate a FET switch stack. The FET switch stack includes a stacked arrangement of body bypass FET switches connected across respective common body resistors. The body bypass FET switches bypass the respective common body resistors during the OFF steady state of the FET switch stack and do not bypass the respective common body resistors during the ON steady state.
    Type: Application
    Filed: September 25, 2023
    Publication date: February 22, 2024
    Inventors: Eric S. SHAPIRO, Ravindranath D. SHRIVASTAVA, Fleming LAM, Matt ALLISON
  • Publication number: 20240030906
    Abstract: Methods and devices to improve the switching speed of radio frequency FET switch stacks are disclosed. The described methods and devices are based on bypassing drain-sources resistors when the FET switch stack is transitioning from an ON to an OFF state. Several implementations of the disclosed teachings are also presented.
    Type: Application
    Filed: August 21, 2023
    Publication date: January 25, 2024
    Inventors: Ravindranath D. SHRIVASTAVA, Simon WILLARD, Peter BACON
  • Patent number: 11835978
    Abstract: Methods and devices to reduce or remove slumps in power supplies are disclosed. The disclosed teachings can serve various applications, such as applications implementing RF switches. Using such teachings, an integrated method can benefit from two different modes of operation where either an external or an internal charge pump can be used to provide a desired negative voltage to various components within the integrated circuit. This can be done by disposing a larger load capacitor outside the integrated circuit and without compromising any die space requirement.
    Type: Grant
    Filed: August 23, 2022
    Date of Patent: December 5, 2023
    Assignee: pSemi Corporation
    Inventors: Ravindranath D. Shrivastava, Payman Shanjani
  • Patent number: 11777485
    Abstract: Methods and devices to improve the switching speed of radio frequency FET switch stacks are disclosed. The described methods and devices are based on bypassing drain-sources resistors when the FET switch stack is transitioning from an ON to an OFF state. Several implementations of the disclosed teachings are also presented.
    Type: Grant
    Filed: April 26, 2022
    Date of Patent: October 3, 2023
    Assignee: PSEMI CORPORATION
    Inventors: Ravindranath D. Shrivastava, Simon Willard, Peter Bacon
  • Publication number: 20230291360
    Abstract: Circuits and methods for improving the noise figure (NF) of an amplifier, particularly an LNA, in high-gain modes while improving the IIP3 of the amplifier in low-gain modes. The source of an amplifier common-source FET is coupled to circuit ground thorough a degeneration circuit comprising a two-port inductor and a bypass switch coupled in parallel with the inductor. A switched feedback circuit is coupled between the gate of the common-source FET and a feedback node in the amplifier output signal path. During a low gain mode, the inductor is entirely bypassed and the enabled feedback circuit lowers the input impedance of the common-source FET and reduces the gain of the amplifier circuit, essentially eliminating the need for a degeneration inductor. During a high gain mode, the source of the common-source FET is coupled to circuit ground through the inductor and the feedback circuit is disabled. Other gain modes are supported.
    Type: Application
    Filed: March 16, 2023
    Publication date: September 14, 2023
    Inventors: Rong Jiang, Khushali Shah, Ravindranath D. Shrivastava, Parvez H. Daruwalla
  • Publication number: 20230283277
    Abstract: A FET switch stack has a stacked arrangement of FET switches, a gate resistor network with ladder resistors and common gate resistors, and a gate resistor bypass arrangement. The bypass arrangement has a first set of bypass switches connected across the gate resistors and a second set of bypass switches connected across the ladder resistors. Bypass occurs during at least a portion of the transition state of the stacked arrangement of FET switches.
    Type: Application
    Filed: March 14, 2023
    Publication date: September 7, 2023
    Inventors: Ravindranath D. SHRIVASTAVA, Alper GENC
  • Patent number: 11722162
    Abstract: Fail-safe methods and devices to protect the receiver of a transceiver in the event of an antenna failure are disclosed. The described devices implement inductive and capacitive elements to replace switches and can be used in any communication system or electronic circuit where the protection of a portion of the device from higher power signals is required. The inductive elements can be implemented using already existing inductors that are constituents of the receiver matching network. Configurations with off-chip capacitive or inductive components are also possible.
    Type: Grant
    Filed: February 2, 2022
    Date of Patent: August 8, 2023
    Assignee: PSEMI CORPORATION
    Inventors: Chengkai Luo, Payman Shanjani, Ravindranath D. Shrivastava
  • Publication number: 20230246659
    Abstract: Fail-safe methods and devices to protect the receiver of a transceiver in the event of an antenna failure are disclosed. The described devices implement inductive and capacitive elements to replace switches and can be used in any communication system or electronic circuit where the protection of a portion of the device from higher power signals is required. The inductive elements can be implemented using already existing inductors that are constituents of the receiver matching network. Configurations with off-chip capacitive or inductive components are also possible.
    Type: Application
    Filed: February 2, 2022
    Publication date: August 3, 2023
    Inventors: Chengkai LUO, Payman SHANJANI, Ravindranath D. SHRIVASTAVA
  • Patent number: 11671135
    Abstract: An apparatus for reducing switching time of RF FET switching devices is described. A FET switch stack includes a stacked arrangement of FET switches and a plurality of gate feed arrangements, each coupled at a different height of the stacked arrangement. A circuital arrangement with a combination of a series RF FET switch and a shunt RF FET switch, each having a stack of FET switches, is also described. The shunt switch has one or more shunt gate feed arrangements with a number of bypass switches that is less than the number of FET switches in the shunt stack.
    Type: Grant
    Filed: October 1, 2021
    Date of Patent: June 6, 2023
    Assignee: PSEMI CORPORATION
    Inventors: Ravindranath D. Shrivastava, Fleming Lam, Payman Shanjani
  • Patent number: 11632107
    Abstract: A FET switch stack has a stacked arrangement of FET switches, a gate resistor network with ladder resistors and common gate resistors, and a gate resistor bypass arrangement. The bypass arrangement has a first set of bypass switches connected across the gate resistors and a second set of bypass switches connected across the ladder resistors. Bypass occurs during at least a portion of the transition state of the stacked arrangement of FET switches.
    Type: Grant
    Filed: October 1, 2021
    Date of Patent: April 18, 2023
    Assignee: PSEMI CORPORATION
    Inventors: Ravindranath D. Shrivastava, Alper Genc
  • Publication number: 20230105033
    Abstract: An apparatus for reducing switching time of RF FET switching devices is described. A FET switch stack includes a stacked arrangement of FET switches and a plurality of gate feed arrangements, each coupled at a different height of the stacked arrangement. A circuital arrangement with a combination of a series RF FET switch and a shunt RF FET switch, each having a stack of FET switches, is also described. The shunt switch has one or more shunt gate feed arrangements with a number of bypass switches that is less than the number of FET switches in the shunt stack.
    Type: Application
    Filed: October 1, 2021
    Publication date: April 6, 2023
    Inventors: Ravindranath D. SHRIVASTAVA, Fleming LAM, Payman SHANJANI
  • Publication number: 20230107974
    Abstract: A FET switch stack has a stacked arrangement of FET switches, a gate resistor network with ladder resistors and common gate resistors, and a gate resistor bypass arrangement. The bypass arrangement has a first set of bypass switches connected across the gate resistors and a second set of bypass switches connected across the ladder resistors. Bypass occurs during at least a portion of the transition state of the stacked arrangement of FET switches.
    Type: Application
    Filed: October 1, 2021
    Publication date: April 6, 2023
    Inventors: Ravindranath D. SHRIVASTAVA, Alper GENC
  • Patent number: 11616475
    Abstract: Circuits and methods for improving the noise figure (NF) of an amplifier, particularly an LNA, in high-gain modes while improving the IIP3 of the amplifier in low-gain modes. The source of an amplifier common-source FET is coupled to circuit ground thorough a degeneration circuit comprising a two-port inductor and a bypass switch coupled in parallel with the inductor. A switched feedback circuit is coupled between the gate of the common-source FET and a feedback node in the amplifier output signal path. During a low gain mode, the inductor is entirely bypassed and the enabled feedback circuit lowers the input impedance of the common-source FET and reduces the gain of the amplifier circuit, essentially eliminating the need for a degeneration inductor. During a high gain mode, the source of the common-source FET is coupled to circuit ground through the inductor and the feedback circuit is disabled. Other gain modes are supported.
    Type: Grant
    Filed: January 5, 2021
    Date of Patent: March 28, 2023
    Assignee: pSemi Corporation
    Inventors: Rong Jiang, Khushali Shah, Ravindranath D. Shrivastava, Parvez Daruwalla
  • Publication number: 20220321113
    Abstract: Methods and devices to improve the switching speed of radio frequency FET switch stacks are disclosed. The described methods and devices are based on bypassing drain-sources resistors when the FET switch stack is transitioning from an ON to an OFF state. Several implementations of the disclosed teachings are also presented.
    Type: Application
    Filed: April 26, 2022
    Publication date: October 6, 2022
    Inventors: Ravindranath D. SHRIVASTAVA, Simon WILLARD, Peter BACON
  • Patent number: 11405031
    Abstract: A common gate resistor bypass arrangement for a stacked arrangement of FET switches, the arrangement including a series combination of an nMOS transistor and a pMOS transistor connected across a common gate resistor. During at least a transition portion of the transition state of the stacked arrangement of FET switches, the nMOS transistor and the pMOS transistor are both in an ON state and bypass the common gate resistor. On the other hand, during at least a steady state portion of the ON steady state and the OFF steady state of the stacked arrangement of FET switches, one of the nMOS transistor and the pMOS transistor is in an OFF state and the other of the nMOS transistor and the pMOS transistor is in an ON state, thus not bypassing the common gate resistor.
    Type: Grant
    Filed: August 16, 2021
    Date of Patent: August 2, 2022
    Assignee: PSEMI CORPORATION
    Inventors: Ravindranath D. Shrivastava, Fleming Lam, Payman Shanjani
  • Patent number: 11405034
    Abstract: A FET switch stack and a method to operate a FET switch stack. The FET switch stack includes a stacked arrangement of body bypass FET switches connected across respective common body resistors. The body bypass FET switches bypass the respective common body resistors during the OFF steady state of the FET switch stack and do not bypass the respective common body resistors during the ON steady state.
    Type: Grant
    Filed: May 14, 2021
    Date of Patent: August 2, 2022
    Assignee: PSEMI CORPORATION
    Inventors: Eric S. Shapiro, Ravindranath D. Shrivastava, Fleming Lam, Matt Allison
  • Publication number: 20220216833
    Abstract: Circuits and methods for improving the noise figure (NF) of an amplifier, particularly an LNA, in high-gain modes while improving the IIP3 of the amplifier in low-gain modes. The source of an amplifier common-source FET is coupled to circuit ground thorough a degeneration circuit comprising a two-port inductor and a bypass switch coupled in parallel with the inductor. A switched feedback circuit is coupled between the gate of the common-source FET and a feedback node in the amplifier output signal path. During a low gain mode, the inductor is entirely bypassed and the enabled feedback circuit lowers the input impedance of the common-source FET and reduces the gain of the amplifier circuit, essentially eliminating the need for a degeneration inductor. During a high gain mode, the source of the common-source FET is coupled to circuit ground through the inductor and the feedback circuit is disabled. Other gain modes are supported.
    Type: Application
    Filed: January 5, 2021
    Publication date: July 7, 2022
    Inventors: Rong Jiang, Khushali Shah, Ravindranath D. Shrivastava, Parvez Daruwalla
  • Patent number: 11329642
    Abstract: Methods and devices to improve the switching speed of radio frequency FET switch stacks are disclosed. The described methods and devices are based on bypassing drain-sources resistors when the FET switch stack is transitioning from an ON to an OFF state. Several implementations of the disclosed teachings are also presented.
    Type: Grant
    Filed: March 15, 2021
    Date of Patent: May 10, 2022
    Assignee: PSEMI CORPORATION
    Inventors: Ravindranath D. Shrivastava, Simon Willard, Peter Bacon
  • Patent number: 10291208
    Abstract: A method and apparatus for adjusting the slope of insertion loss of digital step attenuator (DSA). The DSA is implemented on an integrated circuit. The DSA has two series inductances that are introduced between the input of DSA cell and a resistor in the cell, and the output of DSA cell and another resistor in the cell. In one embodiment, adjustment in the value of the series inductances is as achieved by altering the locations of the input port and the output ports. In another embodiment, adjustment in the value of the inductances is achieved by tailoring the length and width of the conductor trace used to connect the input and output ports to the series resistors. The adjustment in the values of the inductances provides a means by which the roll-off of the insertion loss as a function of frequency in the attenuation state can be controlled.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: May 14, 2019
    Assignee: pSemi Corporation
    Inventors: Ravindranath D. Shrivastava, Raul Inocencio Alidio