Patents by Inventor Keith A. Carter

Keith A. Carter 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: 7538741
    Abstract: A Radio Frequency (RF) structure services an antenna having a characteristic impedance and includes a differential Power Amplifier (PA), a differential Low Noise Amplifier (LNA), and a balun transformer. The differential PA has a differential PA output with a PA differential output impedance. The differential LNA has a differential LNA input with an LNA differential input impedance. The balun transformer has a singled ended winding coupled to the antenna, a differential winding having a first pair of tap connections coupled to the differential PA output and a second pair of tap connections coupled to the differential LNA input, and a turns ratio of the single ended winding and the differential winding. The turns ratio and the first pair of tap connections impedance match the PA differential output impedance to the characteristic impedance of the antenna. The turns ratio and the second pair of tap connections impedance match the LNA differential input impedance to the characteristic impedance of the antenna.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: May 26, 2009
    Assignee: Broadcom Corporation
    Inventors: Jesus Alfonso Castaneda, Ahmadreza (Reza) Rofougaran, Keith A. Carter
  • Patent number: 7423474
    Abstract: A current mirror with selectable filter poles provides a selected low pass filtering function to a DC bias signal generated by the current mirror. Coupled between a first MOSFET and second MOSFET of the current mirror, a low pass filter with selectable filter poles comprises a plurality of resistor-configured MOSFETs coupled to at least one capacitor-configured MOSFET to provide one of a fast settle time and improved filtering for the current mirror in one embodiment of the invention. A first resistor-configured MOSFETs, biased by logic and bias circuitry, provides a low frequency filter pole that provides an improved filtering for the current mirror. A second resistor-configured MOSFET provides a high frequency filter pole that provides a fast charge time to meet a settle time requirement.
    Type: Grant
    Filed: August 23, 2004
    Date of Patent: September 9, 2008
    Assignee: Broadcom Corporation
    Inventors: Arya Reza Behzad, Keith A. Carter
  • Patent number: 7415253
    Abstract: A method for temperature compensation of transmit power of a wireless communication device begins by measuring transmit power of the wireless communication device at a first temperature-based biasing condition to produce a first measured transmit power. The method continues by measuring transmit power of the wireless communication device at a second temperature-based biasing condition to produce a second measured transmit power. The method continues by determining ambient temperature of at least a portion of the wireless communication device based on the first and second measured transmit powers and a relationship between the first and second temperature-based biasing conditions. The method continues by compensating transmit power level of the wireless communication device based on the ambient temperature.
    Type: Grant
    Filed: August 3, 2004
    Date of Patent: August 19, 2008
    Assignee: Broadcom Corporation
    Inventors: Keith A. Carter, Brima B. Ibrahim, Siukai Mak, Ken Gin
  • Patent number: 7379722
    Abstract: An apparatus and method to use a single voltage controlled oscillator (VCO) to generate frequencies to cover multiple frequency bands. The single VCO generates local oscillator signals for more than one frequency band of a communication standard or protocol, such as the IEEE 802.11 standard.
    Type: Grant
    Filed: February 17, 2005
    Date of Patent: May 27, 2008
    Assignee: Broadcom Corporation
    Inventors: Hung-Ming Chien, Keith A. Carter
  • Patent number: 7369096
    Abstract: A Radio Frequency (RF) structure services an antenna having a characteristic impedance and includes a differential Power Amplifier (PA), a differential Low Noise Amplifier (LNA), and a balun transformer. The differential PA has a differential PA output with a PA differential output impedance. The differential LNA has a differential LNA input with an LNA differential input impedance. The balun transformer has a singled ended winding coupled to the antenna, a differential winding having a first pair of tap connections coupled to the differential PA output and a second pair of tap connections coupled to the differential LNA input, and a turns ratio of the single ended winding and the differential winding. The turns ratio and the first pair of tap connections impedance match the PA differential output impedance to the characteristic impedance of the antenna. The turns ratio and the second pair of tap connections impedance match the LNA differential input impedance to the characteristic impedance of the antenna.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: May 6, 2008
    Assignee: Broadcom Corporation
    Inventors: Jesus Alfonso Castaneda, Ahmadreza (Reza) Rofougaran, Keith A. Carter
  • Patent number: 7218170
    Abstract: A current mirror with selectable filter poles provides a selected low pass filtering function to a DC bias signal generated by the current mirror. Coupled between a first MOSFET and second MOSFET of the current mirror, a low pass filter with selectable filter poles comprises a plurality of resistor-configured MOSFETs coupled to at least one capacitor-configured MOSFET to provide one of a fast settle time and improved filtering for the current mirror in one embodiment of the invention. A first resistor-configured MOSFETs, biased by logic and bias circuitry, provides a low frequency filter pole that provides an improved filtering for the current mirror. A second resistor-configured MOSFET provides a high frequency filter pole that provides a fast charge time to meet a settle time requirement.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: May 15, 2007
    Assignee: Broadcom Corporation
    Inventors: Keith A. Carter, Arya Reza Behzad