Patents by Inventor Yuyu Chang

Yuyu Chang 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: 9112508
    Abstract: According to one embodiment, a radio frequency (RF) transceiver includes a local oscillator generator (LOGEN) circuit configured to receive an adaptive supply voltage. The LOGEN circuit is coupled to a variable power supply for providing the adaptive supply voltage. A process monitor for the LOGEN circuit is in communication with the variable power supply through a power supply programming module. As a result, the adaptive supply voltage can be adjusted according to data supplied by the process monitor. A method for adaptively powering a LOGEN circuit comprises providing power to an RF device, monitoring a process corner of said LOGEN circuit, determining a supply voltage corresponding to the process corner, and adjusting the supply voltage to adaptively power the LOGEN circuit.
    Type: Grant
    Filed: June 9, 2010
    Date of Patent: August 18, 2015
    Assignee: BROADCOM CORPORATION
    Inventors: Yuyu Chang, Ahmad Yazdi, Hooman Darabi
  • Patent number: 8903340
    Abstract: Embodiments of a radio frequency (RF) receiver implementing one or more forms of protection to protect devices of the RF receiver from in-band interferers is provided. The RF receiver includes an integrated circuit terminal configured to couple a RF signal received at an antenna to a RF signal path, and a low noise amplifier (LNA) coupled to the RF signal path and configured to amplify the RF signal to provide an amplified RF signal. To protect the LNA from in-band interferers, the RF receiver can further include one or more clamping circuits and/or an over-voltage detector to determine if a peak of the RF signal exceeds an acceptable level.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: December 2, 2014
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Patent number: 8854145
    Abstract: Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs.
    Type: Grant
    Filed: January 14, 2013
    Date of Patent: October 7, 2014
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, John Leete, Walid Ahmed, Wei Luo
  • Patent number: 8838166
    Abstract: Aspects of a method and system for processing signals in a high performance receive chain may include amplifying a plurality of radio frequency signals in one or more respective one or ones of a plurality of amplifier chains in a multistandard radio frequency front-end, which may comprise one or more shared processing stages. The plurality of radio frequency signals may be compliant with a plurality of radio frequency communication standards and may be received concurrently. The one or more shared processing stages may be shared between two or more of the plurality of amplifier chains. Each of the two or more of the plurality of amplifier chains may be operable to amplify signals compliant with different radio frequency communication standards.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: September 16, 2014
    Assignee: Broadcom Corporation
    Inventors: Arya Behzad, Adedayo Ojo, Yuyu Chang, Hung-Ming Chien, Kishore Rama Rao, Guruprasad Seetharam
  • Patent number: 8410823
    Abstract: Aspects of a method and system for an integrated LC resonant current gain boosting amplifier may include amplifying within a chip, via an on-chip LC current gain circuit, an alternating current (AC) generated by an on-chip voltage-to-current converter, and converting within the chip, via an on-chip current-to-voltage circuit; the amplified alternating current to an output voltage. The on-chip LC current gain circuit comprises only passive components, which may include one or more resistors, one or more capacitors, and one or more inductors.
    Type: Grant
    Filed: January 4, 2007
    Date of Patent: April 2, 2013
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Meng-An Pan
  • Patent number: 8385877
    Abstract: Fully integrated compact cross-coupled low noise amplifier. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A differential 100? input impedance is provided by this design. A higher than typical power supply voltage can be employed (if desired) to accommodate one possible implementation that includes two parallel implemented resistors to ground.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: February 26, 2013
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Patent number: 8374560
    Abstract: Aspects of a method and system for processing signals in a high performance receive chain may include amplifying a plurality of radio frequency signals in one or more respective one or ones of a plurality of amplifier chains in a multistandard radio frequency front-end, which may comprise one or more shared processing stages. The plurality of radio frequency signals may be compliant with a plurality of radio frequency communication standards and may be received concurrently. The one or more shared processing stages may be shared between two or more of the plurality of amplifier chains. Each of the two or more of the plurality of amplifier chains may be operable to amplify signals compliant with different radio frequency communication standards.
    Type: Grant
    Filed: September 15, 2010
    Date of Patent: February 12, 2013
    Assignee: Broadcom Corporation
    Inventors: Arya Behzad, Adedayo Ojo, Yuyu Chang, Hung-Ming Chien, Kishore Rama Rao, Guruprasad Seetharam
  • Patent number: 8369818
    Abstract: Embodiments of a radio frequency (RF) receiver implementing one or more forms of protection to protect devices of the RF receiver from in-band interferers is provided. The RF receiver includes an integrated circuit terminal configured to couple a RF signal received at an antenna to a RF signal path, and a low noise amplifier (LNA) coupled to the RF signal path and configured to amplify the RF signal to provide an amplified RF signal. To protect the LNA from in-band interferers, the RF receiver can further include one or more clamping circuits and/or an over-voltage detector to determine if a peak of the RF signal exceeds an acceptable level.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: February 5, 2013
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Patent number: 8354890
    Abstract: Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs.
    Type: Grant
    Filed: October 28, 2010
    Date of Patent: January 15, 2013
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, John Leete, Walid Ahmed, Wei Luo
  • Publication number: 20120329417
    Abstract: Embodiments of a radio frequency (RF) receiver implementing one or more forms of protection to protect devices of the RF receiver from in-band interferers is provided. The RF receiver includes an integrated circuit terminal configured to couple a RF signal received at an antenna to a RF signal path, and a low noise amplifier (LNA) coupled to the RF signal path and configured to amplify the RF signal to provide an amplified RF signal. To protect the LNA from in-band interferers, the RF receiver can further include one or more clamping circuits and/or an over-voltage detector to determine if a peak of the RF signal exceeds an acceptable level.
    Type: Application
    Filed: June 27, 2011
    Publication date: December 27, 2012
    Applicant: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Publication number: 20120329418
    Abstract: Embodiments of a radio frequency (RF) receiver implementing one or more forms of protection to protect devices of the RF receiver from in-band interferers is provided. The RF receiver includes an integrated circuit terminal configured to couple a RF signal received at an antenna to a RF signal path, and a low noise amplifier (LNA) coupled to the RF signal path and configured to amplify the RF signal to provide an amplified RF signal. To protect the LNA from in-band interferers, the RF receiver can further include one or more clamping circuits and/or an over-voltage detector to determine if a peak of the RF signal exceeds an acceptable level.
    Type: Application
    Filed: June 27, 2011
    Publication date: December 27, 2012
    Applicant: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Patent number: 8204468
    Abstract: Embodiments of the present invention provide DC biasing circuits. Embodiments employ an open loop scheme, instead of a closed loop scheme as used in conventional circuits. In addition, embodiments generate a DC bias voltage that is independent of temperature, process, and power supply variations. Further, embodiments require low amounts of power and silicon.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: June 19, 2012
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Patent number: 8183905
    Abstract: A method to provide a low-power clock signal or a low-noise clock signal is described herein. It is determined whether a low-power mode or a low-noise mode is in use. A voltage reference input of a low-dropout voltage regulator (LDO) is switched to a low-power voltage reference for low-power mode and to a low-noise voltage reference for low-noise mode. The LDO provides a constant voltage output to a crystal oscillator. A clock signal is generated using the crystal oscillator. The clock signal is limited using a low-power limiter to generate a low-power output clock signal and/or is limited using a low-noise limiter to generate a low-noise clock signal. The low-power output clock signal or the low-noise output clock signal is selected using a mux.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: May 22, 2012
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Qiang Li, John Leete, Hooman Darabi, Yiannis Kokolakis
  • Publication number: 20120068780
    Abstract: Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs.
    Type: Application
    Filed: October 28, 2010
    Publication date: March 22, 2012
    Applicant: Broadcom Corporation
    Inventors: Yuyu Chang, John Leete, Walid Ahmed, Wei Luo
  • Publication number: 20110306311
    Abstract: According to one embodiment, a radio frequency (RF) transceiver includes a local oscillator generator (LOGEN) circuit configured to receive an adaptive supply voltage. The LOGEN circuit is coupled to a variable power supply for providing the adaptive supply voltage. A process monitor for the LOGEN circuit is in communication with the variable power supply through a power supply programming module. As a result, the adaptive supply voltage can be adjusted according to data supplied by the process monitor. A method for adaptively powering a LOGEN circuit comprises providing power to an RF device, monitoring a process corner of said LOGEN circuit, determining a supply voltage corresponding to the process corner, and adjusting the supply voltage to adaptively power the LOGEN circuit.
    Type: Application
    Filed: June 9, 2010
    Publication date: December 15, 2011
    Applicant: BROADCOM CORPORATION
    Inventors: Yuyu Chang, Ahmad Yazdi, Hooman Darabi
  • Patent number: 8073417
    Abstract: Aspects of a method and system for a transformer-based high performance cross-coupled low noise amplifier may include one or more circuits that integrate within a single chip, a balun with a low-noise amplifier. A DC current biasing path for the low-noise amplifier may be provided through the integrated balun. The low-noise amplifier may be configured as a cross-coupled low-noise amplifier, where the balun may be directly coupled to the cross-coupled low-noise amplifier. The balun may comprise two or more inductors, wherein one or more of the inductors may provide an electrical path for allowing a DC bias current to flow to ground. Integrating a balun on a single chip with a low-noise amplifier may allow the use of a single received signal input terminal. The biasing voltage may be selected to optimize performance of the low-noise amplifier.
    Type: Grant
    Filed: December 31, 2006
    Date of Patent: December 6, 2011
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Arya Behzad
  • Patent number: 7990216
    Abstract: Cross-coupled low noise amplifier for cellular applications. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. In one embodiment, this design is particularly adaptable to cellular telephone applications. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A very high output impedance is provided by using two transistors (implemented in a triple well configuration) with resistive source degeneration. A higher than typical power supply voltage can be employed (if desired) to accommodate the voltage drops of the resistors and transistors.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: August 2, 2011
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Publication number: 20110143822
    Abstract: Fully integrated compact cross-coupled low noise amplifier. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A differential 100? input impedance is provided by this design. A higher than typical power supply voltage can be employed (if desired) to accommodate one possible implementation that includes two parallel implemented resistors to ground.
    Type: Application
    Filed: February 23, 2011
    Publication date: June 16, 2011
    Applicant: BROADCOM CORPORATION
    Inventors: Yuyu Chang, Hooman Darabi
  • Publication number: 20110018604
    Abstract: A method to provide a low-power clock signal or a low-noise clock signal is described herein. It is determined whether a low-power mode or a low-noise mode is in use. A voltage reference input of a low-dropout voltage regulator (LDO) is switched to a low-power voltage reference for low-power mode and to a low-noise voltage reference for low-noise mode. The LDO provides a constant voltage output to a crystal oscillator. A clock signal is generated using the crystal oscillator. The clock signal is limited using a low-power limiter to generate a low-power output clock signal and/or is limited using a low-noise limiter to generate a low-noise clock signal. The low-power output clock signal or the low-noise output clock signal is selected using a mux.
    Type: Application
    Filed: August 11, 2009
    Publication date: January 27, 2011
    Applicant: Broadcom Corporation
    Inventors: Yuyu Chang, Qiang Li, John Leete, Hooman Darabi, Yiannis Kokolakis
  • Publication number: 20110003574
    Abstract: Embodiments of the present invention provide constant output DC biasing circuits. Embodiments employ an open loop scheme, instead of a closed loop scheme as used in conventional circuits. In addition, embodiments generate a DC bias voltage that is independent of temperature, process, and power supply variations. Further, embodiments require low amounts of power and silicon.
    Type: Application
    Filed: July 1, 2009
    Publication date: January 6, 2011
    Applicant: Broadcom Corporation
    Inventors: Yuyu CHANG, Hooman DARABI