Patents by Inventor Fleming Lam
Fleming Lam 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).
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Publication number: 20240097656Abstract: 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: ApplicationFiled: September 19, 2022Publication date: March 21, 2024Inventors: Ravindranath D. SHRIVASTAVA, Fleming LAM, Payman SHANJANI
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Publication number: 20240063789Abstract: 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: ApplicationFiled: September 25, 2023Publication date: February 22, 2024Inventors: Eric S. SHAPIRO, Ravindranath D. SHRIVASTAVA, Fleming LAM, Matt ALLISON
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Patent number: 11671135Abstract: 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: GrantFiled: October 1, 2021Date of Patent: June 6, 2023Assignee: PSEMI CORPORATIONInventors: Ravindranath D. Shrivastava, Fleming Lam, Payman Shanjani
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Publication number: 20230105033Abstract: 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: ApplicationFiled: October 1, 2021Publication date: April 6, 2023Inventors: Ravindranath D. SHRIVASTAVA, Fleming LAM, Payman SHANJANI
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Patent number: 11405031Abstract: 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: GrantFiled: August 16, 2021Date of Patent: August 2, 2022Assignee: PSEMI CORPORATIONInventors: Ravindranath D. Shrivastava, Fleming Lam, Payman Shanjani
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Patent number: 11405035Abstract: 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: GrantFiled: July 13, 2021Date of Patent: August 2, 2022Assignee: PSEMI CORPORATIONInventors: Alper Genc, Fleming Lam, Eric S. Shapiro, Ravindranath Shrivastava
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Patent number: 11405034Abstract: 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: GrantFiled: May 14, 2021Date of Patent: August 2, 2022Assignee: PSEMI CORPORATIONInventors: Eric S. Shapiro, Ravindranath D. Shrivastava, Fleming Lam, Matt Allison
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Patent number: 10432238Abstract: Detuning and isolation techniques for a multiband tunable matching network used in multi-transceiver RF systems. Embodiments include an amplifier and a multiband tunable matching network (MN) coupled to the amplifier. The multiband tunable MN is configured to detune to an isolation OFF state from an ON state, wherein the match tuning in the isolation OFF state is different than match tuning in the ON state. In an example detuning, the match tuning in the isolation OFF state is in a different frequency band than a frequency band of match tuning in the ON state and is selected based on the frequency band of match tuning in the ON state.Type: GrantFiled: June 11, 2018Date of Patent: October 1, 2019Assignee: pSemi CorporationInventors: Chengkai Luo, Fleming Lam
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Patent number: 10277201Abstract: Circuits and methods for eliminating or mitigating the amount of temperature-dependent variation in the relative attenuation of a multi-valued digital step attenuator (DSA) by using resistive components having temperature-dependent resistance values that compensate for or offset changes in the temperature-dependent ON resistance (RON) of the switches within the DSA. In some embodiments, DSA attenuator cell switches are fabricated to have positive first-order resistance temperature (FORT) coefficients, while temperature-compensating series attenuation resistances are fabricated as a positive FORT coefficient resistor and temperature-compensating shunt resistances are fabricated as either a negative FORT coefficient resistor or a combination of a negative FORT coefficient resistor in parallel with a positive FORT coefficient resistor.Type: GrantFiled: May 16, 2018Date of Patent: April 30, 2019Assignee: pSemi CorporationInventor: Fleming Lam
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Publication number: 20180262181Abstract: Circuits and methods for eliminating or mitigating the amount of temperature-dependent variation in the relative attenuation of a multi-valued digital step attenuator (DSA) by using resistive components having temperature-dependent resistance values that compensate for or offset changes in the temperature-dependent ON resistance (RON) of the switches within the DSA. In some embodiments, DSA attenuator cell switches are fabricated to have positive first-order resistance temperature (FORT) coefficients, while temperature-compensating series attenuation resistances are fabricated as a positive FORT coefficient resistor and temperature-compensating shunt resistances are fabricated as either a negative FORT coefficient resistor or a combination of a negative FORT coefficient resistor in parallel with a positive FORT coefficient resistor.Type: ApplicationFiled: May 16, 2018Publication date: September 13, 2018Inventor: Fleming Lam
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Patent number: 10003322Abstract: Circuits and methods for eliminating or mitigating the amount of temperature-dependent variation in the relative attenuation of a multi-valued digital step attenuator (DSA) by using resistive components having temperature-dependent resistance values that compensate for or offset changes in the temperature-dependent ON resistance (RON) of the switches within the DSA. In some embodiments, DSA attenuator cell switches are fabricated to have positive first-order resistance temperature (FORT) coefficients, while temperature-compensating series attenuation resistances are fabricated as a positive FORT coefficient resistor and temperature-compensating shunt resistances are fabricated as either a negative FORT coefficient resistor or a combination of a negative FORT coefficient resistor in parallel with a positive FORT coefficient resistor.Type: GrantFiled: October 6, 2016Date of Patent: June 19, 2018Assignee: pSemi CorporationInventor: Fleming Lam
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Publication number: 20180102763Abstract: Circuits and methods for eliminating or mitigating the amount of temperature-dependent variation in the relative attenuation of a multi-valued digital step attenuator (DSA) by using resistive components having temperature-dependent resistance values that compensate for or offset changes in the temperature-dependent ON resistance (RON) of the switches within the DSA. In some embodiments, DSA attenuator cell switches are fabricated to have positive first-order resistance temperature (FORT) coefficients, while temperature-compensating series attenuation resistances are fabricated as a positive FORT coefficient resistor and temperature-compensating shunt resistances are fabricated as either a negative FORT coefficient resistor or a combination of a negative FORT coefficient resistor in parallel with a positive FORT coefficient resistor.Type: ApplicationFiled: October 6, 2016Publication date: April 12, 2018Inventor: Fleming Lam
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Patent number: 9509263Abstract: Biasing methods and devices for amplifiers are described. The described methods generate bias voltages proportional to the amplifier output voltage to control stress voltages across transistors used within the amplifier.Type: GrantFiled: February 13, 2015Date of Patent: November 29, 2016Assignee: Peregrine Semiconductor CorporationInventor: Fleming Lam
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Patent number: 9184731Abstract: A method and circuit for significantly reducing positive switching transients (glitches) of digital step attenuators (DSA's) by controlling the timing of state transitions for individual attenuator stages within a DSA. Such control prevents the DSA output power from peaking during attenuation state transitions and ensures that any transient glitch during the transition results in reduced power at the DSA output. Attenuation stage timing delay can be implemented on an integrated circuit die or “chip” for monolithic implementations of a DSA by adding circuitry which ensures that any attenuation state changes result in increased attenuation rather than decreased attenuation, thereby reducing or eliminating positive transient glitches at the DSA output.Type: GrantFiled: December 16, 2013Date of Patent: November 10, 2015Assignee: Peregrine Semiconductor CorporationInventor: Fleming Lam
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Publication number: 20150311876Abstract: Biasing methods and devices for amplifiers are described. The described methods generate bias voltages proportional to the amplifier output voltage to control stress voltages across transistors used within the amplifier.Type: ApplicationFiled: February 13, 2015Publication date: October 29, 2015Inventor: Fleming Lam
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Publication number: 20150171828Abstract: A method and circuit for significantly reducing positive switching transients (glitches) of digital step attenuators (DSA's) by controlling the timing of state transitions for individual attenuator stages within a DSA. Such control prevents the DSA output power from peaking during attenuation state transitions and ensures that any transient glitch during the transition results in reduced power at the DSA output. Attenuation stage timing delay can be implemented on an integrated circuit die or “chip” for monolithic implementations of a DSA by adding circuitry which ensures that any attenuation state changes result in increased attenuation rather than decreased attenuation, thereby reducing or eliminating positive transient glitches at the DSA output.Type: ApplicationFiled: December 16, 2013Publication date: June 18, 2015Applicant: PEREGRINE SEMICONDUCTOR CORPORATIONInventor: Fleming Lam
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Patent number: 8994448Abstract: Systems and methods for generating internal chip supply bias from high voltage control line inputs are presented. One of a plurality of the high voltage control lines is selected and accordingly internal path switching circuitry is enabled to pass the selected high voltage control line while protecting the associated components from over-stress.Type: GrantFiled: March 29, 2013Date of Patent: March 31, 2015Assignee: Peregrine Semiconductor CorporationInventor: Fleming Lam
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Patent number: 8970303Abstract: Biasing methods and devices for amplifiers are described. The described methods generate bias voltages proportional to the amplifier output voltage to control stress voltages across transistors used within the amplifier.Type: GrantFiled: January 7, 2013Date of Patent: March 3, 2015Assignee: Peregrine Semiconductor CorporationInventor: Fleming Lam
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Publication number: 20140022016Abstract: Biasing methods and devices for amplifiers are described. The described methods generate bias voltages proportional to the amplifier output voltage to control stress voltages across transistors used within the amplifier.Type: ApplicationFiled: January 7, 2013Publication date: January 23, 2014Applicant: PEREGRINE SEMICONDUCTOR CORPORATIONInventor: Fleming Lam
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Patent number: 8373490Abstract: Embodiments of RF and DC switching are described generally herein. Other embodiments may be described and claimed.Type: GrantFiled: October 27, 2010Date of Patent: February 12, 2013Assignee: Peregrine Semiconductor CorporationInventors: Mark L. Burgener, Fleming Lam