Patents by Inventor Ravindranath Shrivastava

Ravindranath 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).

  • Patent number: 11405035
    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: July 13, 2021
    Date of Patent: August 2, 2022
    Assignee: PSEMI CORPORATION
    Inventors: Alper Genc, Fleming Lam, Eric S. Shapiro, Ravindranath Shrivastava
  • Publication number: 20210021257
    Abstract: A phase shifter cell and multiple coupled phase shifter cells that mitigate signal glitches arising from phase state changes by a combination of design architecture and control signal timing. Specifically, one or more of the following three concepts are employed to mitigate insertion loss glitches and control phase behavior during phase state transitions: the timing of switching for each switched half-cell (e.g., including series and/or shunt reactance elements, such as inductors and/or capacitors) within a phase shifter cell is controlled in such a way that the reactance elements do not all switch at the same time; use of a “make before break” timing scheme for combination or “multi-state” phase shifter cells; and/or arranging the timing of each phase shifter cell in a set of multiple coupled phase shifter cells such that the individual cells do not all switch at the same time.
    Type: Application
    Filed: July 30, 2020
    Publication date: January 21, 2021
    Inventors: Ravindranath Shrivastava, Peter Bacon
  • Patent number: 10312885
    Abstract: A self-matching phase shifter/attenuator including several incremental impedance matched phase shifter/attenuator elements is disclosed. Each incremental impedance matched phase shifter element comprises a reactive component (such as either a capacitor or inductor) that can be coupled in shunt to the signal path. The shunt reactive component is coupled in series with a ground switch. When closed, the ground switch connects the shunt reactive component to ground. When the ground switch is open, the switch removes the shunt reactive component from the circuit. In addition, each incremental impedance matched phase shifter element comprises a series reactive component having a reactance that is typically equal and inverse of that of the shunt reactive component.
    Type: Grant
    Filed: February 15, 2017
    Date of Patent: June 4, 2019
    Assignee: pSemi Corporation
    Inventor: Ravindranath Shrivastava
  • Patent number: 10205439
    Abstract: An apparatus for selectively providing attenuation with minimal relative phase error. A Digital Step Attenuator (DSA) is implemented on an integrated circuit (IC). Each cell of the DSA has a series compensation inductance that is introduced between an input to the cell and a resistor on the cell. The series compensation inductance allows the location of a pole present in the transfer function of the cell to be manipulated. By controlling the location of the pole in the transfer function of the DSA, the relative phase error of the cell can be controlled. In another disclosed embodiment, the capacitance of a shunt compensation capacitor is increased to manipulate a pole in the transfer function of a DSA cell.
    Type: Grant
    Filed: September 2, 2016
    Date of Patent: February 12, 2019
    Assignee: pSemi Corporation
    Inventors: Ravindranath Shrivastava, Kristian Madsen
  • Patent number: 10193531
    Abstract: Digital step attenuator (DSA) configurations which are capable of handling high power signals, have low insertion loss and parasitic effects, have few or no glitches between state transitions, have minimal effect on chip area and power dissipation on an integrated circuit (IC) die (or “chip”), and provide flexibility of design for various applications. Embodiments utilize one or more architectural features and/or design techniques to achieve such characteristics, including reduced resistor and FET switch sizes, reduced series stack sizes, unidirectional input power configurations, capacitor compensation to match bandwidth characteristics, activating low-power thermometer-weighted attenuator cells only after activating higher power thermometer-weighted attenuator cells, and reducing signal transients (glitches) using a thermometer-weighted configuration of attenuator cells.
    Type: Grant
    Filed: January 14, 2016
    Date of Patent: January 29, 2019
    Assignee: pSemi Corporation
    Inventor: Ravindranath Shrivastava
  • Publication number: 20180234080
    Abstract: A self-matching phase shifter/attenuator including several incremental impedance matched phase shifter/attenuator elements is disclosed. Each incremental impedance matched phase shifter element comprises a reactive component (such as either a capacitor or inductor) that can be coupled in shunt to the signal path. The shunt reactive component is coupled in series with a ground switch. When closed, the ground switch connects the shunt reactive component to ground. When the ground switch is open, the switch removes the shunt reactive component from the circuit. In addition, each incremental impedance matched phase shifter element comprises a series reactive component having a reactance that is typically equal and inverse of that of the shunt reactive component.
    Type: Application
    Filed: February 15, 2017
    Publication date: August 16, 2018
    Inventor: Ravindranath Shrivastava
  • Publication number: 20180212590
    Abstract: A phase shifter cell and multiple coupled phase shifter cells that mitigate signal glitches arising from phase state changes by a combination of design architecture and control signal timing. Specifically, one or more of the following three concepts are employed to mitigate insertion loss glitches and control phase behavior during phase state transitions: the timing of switching for each switched half-cell (e.g., including series and/or shunt reactance elements, such as inductors and/or capacitors) within a phase shifter cell is controlled in such a way that the reactance elements do not all switch at the same time; use of a “make before break” timing scheme for combination or “multi-state” phase shifter cells; and/or arranging the timing of each phase shifter cell in a set of multiple coupled phase shifter cells such that the individual cells do not all switch at the same time.
    Type: Application
    Filed: January 24, 2017
    Publication date: July 26, 2018
    Inventors: Ravindranath Shrivastava, Peter Bacon
  • Patent number: 9935614
    Abstract: Multi-state radio frequency (RF) attenuator configurations that include bridged-T type, pi-type, and T-type structures each having a programmable throughput section and a coupled programmable shunt section. The throughput sections and shunt sections may be configured in various combinations of parallel and serial fixed or selectable resistance elements such that multiple resistance states and impedance matching states can be programmatically selected, and may include stacked switch elements to withstand applied voltages to a specified design level.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: April 3, 2018
    Assignee: pSemi Corporation
    Inventor: Ravindranath Shrivastava
  • Patent number: 9917613
    Abstract: A digitally controlled phase shifter and (optional) attenuator circuit that has both a broad range as well as a fine-tuning resolution. Embodiments maintain a full 360° phase range while providing nth-bit least-significant bit (LSB) resolution across the entire range of possible phase shift and attenuation states, and compensate for the effect of frequency and/or PVT variations. In embodiments, two or more range partitionings can be defined that can be monotonic over respective sub-ranges while providing full coverage when combined. One such partitioning is a “coarse+fine” architecture. Embodiments of the coarse+fine architecture provide for greater than 360° of range for phase shifting and more than the total nominal design level for attenuation, and provide for fine ranges for both phase shifting and attenuation that are greater than the LSB of the corresponding coarse ranges for phase shifting and attenuation.
    Type: Grant
    Filed: January 24, 2017
    Date of Patent: March 13, 2018
    Assignee: pSemi Corporation
    Inventors: Peter Bacon, Matt Allison, Ravindranath Shrivastava
  • Publication number: 20170207769
    Abstract: Digital step attenuator (DSA) configurations which are capable of handling high power signals, have low insertion loss and parasitic effects, have few or no glitches between state transitions, have minimal effect on chip area and power dissipation on an integrated circuit (IC) die (or “chip”), and provide flexibility of design for various applications. Embodiments utilize one or more architectural features and/or design techniques to achieve such characteristics, including reduced resistor and FET switch sizes, reduced series stack sizes, unidirectional input power configurations, capacitor compensation to match bandwidth characteristics, activating low-power thermometer-weighted attenuator cells only after activating higher power thermometer-weighted attenuator cells, and reducing signal transients (glitches) using a thermometer-weighted configuration of attenuator cells.
    Type: Application
    Filed: January 14, 2016
    Publication date: July 20, 2017
    Inventor: Ravindranath Shrivastava
  • Publication number: 20170104471
    Abstract: Multi-state radio frequency (RF) attenuator configurations that include bridged-T type, pi-type, and T-type structures each having a programmable throughput section and a coupled programmable shunt section. The throughput sections and shunt sections may be configured in various combinations of parallel and serial fixed or selectable resistance elements such that multiple resistance states and impedance matching states can be programmatically selected, and may include stacked switch elements to withstand applied voltages to a specified design level.
    Type: Application
    Filed: October 31, 2016
    Publication date: April 13, 2017
    Inventor: Ravindranath Shrivastava
  • Patent number: 9531359
    Abstract: Multi-state radio frequency (RF) attenuator configurations that include bridged-T type, pi-type, and T-type structures each having a programmable throughput section and a coupled programmable shunt section. The throughput sections and shunt sections may be configured in various combinations of parallel and serial fixed or selectable resistance elements such that multiple resistance states and impedance matching states can be programmatically selected, and may include stacked switch elements to withstand applied voltages to a specified design level.
    Type: Grant
    Filed: October 8, 2015
    Date of Patent: December 27, 2016
    Assignee: Peregrine Semiconductor Corporation
    Inventor: Ravindranath Shrivastava
  • Publication number: 20160373086
    Abstract: An apparatus for selectively providing attenuation with minimal relative phase error. A Digital Step Attenuator (DSA) is implemented on an integrated circuit (IC). Each cell of the DSA has a series compensation inductance that is introduced between an input to the cell and a resistor on the cell. The series compensation inductance allows the location of a pole present in the transfer function of the cell to be manipulated. By controlling the location of the pole in the transfer function of the DSA, the relative phase error of the cell can be controlled. In another disclosed embodiment, the capacitance of a shunt compensation capacitor is increased to manipulate a pole in the transfer function of a DSA cell.
    Type: Application
    Filed: September 2, 2016
    Publication date: December 22, 2016
    Inventors: Ravindranath Shrivastava, Kristian Madsen
  • Patent number: 9444432
    Abstract: An apparatus for selectively providing attenuation with minimal relative phase error. A Digital Step Attenuator (DSA) is implemented on an integrated circuit (IC). Each cell of the DSA has a series compensation inductance that is introduced between an input to the cell and a resistor on the cell. The series compensation inductance allows the location of a pole present in the transfer function of the cell to be manipulated. By controlling the location of the pole in the transfer function of the DSA, the relative phase error of the cell can be controlled. In another disclosed embodiment, the capacitance of a shunt compensation capacitor is increased to manipulate a pole in the transfer function of a DSA cell.
    Type: Grant
    Filed: November 11, 2014
    Date of Patent: September 13, 2016
    Assignee: Peregrine Semiconductor Corporation
    Inventors: Ravindranath Shrivastava, Kristian Madsen
  • Publication number: 20160134259
    Abstract: An apparatus for selectively providing attenuation with minimal relative phase error. A Digital Step Attenuator (DSA) is implemented on an integrated circuit (IC). Each cell of the DSA has a series compensation inductance that is introduced between an input to the cell and a resistor on the cell. The series compensation inductance allows the location of a pole present in the transfer function of the cell to be manipulated. By controlling the location of the pole in the transfer function of the DSA, the relative phase error of the cell can be controlled. In another disclosed embodiment, the capacitance of a shunt compensation capacitor is increased to manipulate a pole in the transfer function of a DSA cell.
    Type: Application
    Filed: November 11, 2014
    Publication date: May 12, 2016
    Inventors: Ravindranath Shrivastava, Kristian Madsen