Patents Assigned to Cree Microwave, Inc.
  • Publication number: 20050280087
    Abstract: An LDMOS transistor includes a source capacitor structure and a gate-drain shield which can be interconnected whereby the source capacitor can be grounded to provide an RF ground for the shield and whereby the RF shield can have a positive DC voltage bias to enhance laterally diffused drain conductance without increasing doping therein.
    Type: Application
    Filed: June 16, 2004
    Publication date: December 22, 2005
    Applicant: CREE MICROWAVE, INC.
    Inventors: Jeff Babcock, Johan Darmawan, John Mason
  • Publication number: 20050280080
    Abstract: A LDMOS transistor having a gate shield provides reduced drain coupling to the gate shield and source by restricting the thickness of the gate shield and by confining a source contact to the source region without overlap of the gate.
    Type: Application
    Filed: June 16, 2004
    Publication date: December 22, 2005
    Applicant: CREE MICROWAVE, INC.
    Inventors: Jeff Babcock, Johan Darmawan, John Mason, Ly Diep
  • Publication number: 20050280085
    Abstract: An LDMOS transistor includes a trench source capacitor structure and a gate-drain shield which can be interconnected whereby the source capacitor can be grounded to provide an RF ground for the shield and whereby the RF shield can have a positive DC voltage bias to enhance laterally diffused drain conductance without increasing doping therein. The trench capacitor structure can include one or more adjacent trenches to increase capacitor plate area.
    Type: Application
    Filed: June 16, 2004
    Publication date: December 22, 2005
    Applicant: CREE MICROWAVE, INC.
    Inventors: Jeff Babcock, Johan Darmawan, John Mason
  • Publication number: 20050280101
    Abstract: Reduced source resistance is realized in a laterally diffused MOS transistor by fabricating the transistor in a P-doped epitaxial layer on an N-doped semiconductor substrate and using a trench contact for ohmically connecting the N-doped source region to the N-doped substrate.
    Type: Application
    Filed: June 16, 2004
    Publication date: December 22, 2005
    Applicant: CREE MICROWAVE, INC.
    Inventors: Jeff Babcock, Johan Darmawan, John Mason
  • Patent number: 6900501
    Abstract: A semiconductor device is fabricated in a silicon on insulator (SOI) substrate including a supporting silicon substrate, a silicon oxide layer supported by the substrate, and a silicon layer overlying the silicon oxide layer. An electrical component is fabricated in the silicon layer over a portion of the silicon oxide layer, and then the substrate opposite from the component is masked and etched. A metal layer is then formed in the portion of the substrate which has been removed by etching with the metal layer providing heat removal from the component. In an alternative embodiment, the silicon oxide layer overlying the portion of the substrate is removed with the metal layer abutting the silicon layer. In fabricating the device, preferential etching is employed to remove the silicon in the substrate with the silicon oxide functioning as an etchant stop. A two step process can be employed including a first oxide etch to etch the bulk of the silicon and then a more selective but slower etch.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: May 31, 2005
    Assignee: CREE Microwave, Inc.
    Inventor: Johan Agus Darmawan
  • Patent number: 6888167
    Abstract: Light emitting device die having a mesa configuration on a substrate and an electrode on the mesa are attached to a submount in a flip-chip configuration by forming predefined pattern of conductive die attach material on at least one of the electrode and the submount and mounting the light emitting device die to the submount. The predefined pattern of conductive die attach material is selected so as to prevent the conductive die attach material from contacting regions of having opposite conductivity types when the light emitting device die is mounted to the submount. The predefined pattern of conductive die attach material may provide a volume of die attach material that is less than a volume defined by an area of the electrode and a distance between the electrode and the submount. Light emitting device dies having predefined patterns of conductive die attach material are also provided.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: May 3, 2005
    Assignees: Cree, Inc., Cree Microwave, Inc.
    Inventors: David B. Slater, Jr., Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley
  • Patent number: 6822321
    Abstract: The linearity of a wideband RF power transistor amplifier is improved by including output matching circuit and an integrated bias/RF diplexer with RF and video bypassing capacitor network within the transistor package and connected directly to the transistor. By placing the RF and video bypass power supply circuitry within the package and close to the transistor, the input impedance resonance can be increased from approximately 50 MHz to over 125 MHz, thereby reducing AM/PM distortion in the output signal.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: November 23, 2004
    Assignee: CREE Microwave, Inc.
    Inventor: Emil James Crescenzi, Jr.
  • Patent number: 6819184
    Abstract: The linearity of a transistor amplifier comprising a plurality of transistors operating parallel is improved by reducing the odd order transconductance derivatives of signals generated by the transistors. The transistors can be provided in groups with each group having a different bias voltage applied thereto or each group of transistors can have a different input signal applied thereto. The groups of transistors can have different physical parameters such as the width to length ratio of gates in field effect transistors and threshold voltages for the transistors.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: November 16, 2004
    Assignee: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood, John Phillip Quinn
  • Patent number: 6798295
    Abstract: Disclosed are a multi-chip power amplifier comprising a plurality chips with each chip being a transistor amplifier, and a housing in which all of the semiconductor chips are mounted. A plurality of input leads extend into the housing and a plurality of output leads extend from the housing. A plurality of first matching networks couple a semiconductor chip to an input lead and a plurality of second matching networks couple each semiconductor chip to an output lead whereby each chip has its own input lead and output lead. By providing all amplifier chips within a single housing with matching networks within the housing coupling the chips to the input and output leads, manufacturing cost is reduced and the overall package footprint on a mounting substrate is reduced. Further, the close proximity of the chips within the housing reduces phase differences among signals in the semiconductor chips.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: September 28, 2004
    Assignee: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood, John Phillip Quinn
  • Patent number: 6791417
    Abstract: An RF power amplifier circuit for amplifying an RF signal over a broad range of power with improved efficiency includes a carrier amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power is disclosed. A plurality of peak amplifiers are connected in parallel with the carrier amplifier with each of the peak amplifiers being biased to sequentially provide an amplified output signal after the carrier amplifier approaches saturation. The input signal is applied through a signal splitter to the carrier amplifier and the plurality of peak amplifiers, and an output for receiving amplified output signals from the carrier amplifier and the plurality of peak amplifiers includes a resistive load R/2. The split input signal is applied through a 90° transformer to the carrier amplifier, and the outputs of the peak amplifiers are applied through 90° transformers to a output load.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: September 14, 2004
    Assignee: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood
  • Publication number: 20040113697
    Abstract: Disclosed are a multi-chip power amplifier comprising a plurality chips with each chip being a transistor amplifier, and a housing in which all of the semiconductor chips are mounted. A plurality of input leads extend into the housing and a plurality of output leads extend from the housing. A plurality of first matching networks couple a semiconductor chip to an input lead and a plurality of second matching networks couple each semiconductor chip to an output lead whereby each chip has its own input lead and output lead. By providing all amplifier chips within a single housing with matching networks within the housing coupling the chips to the input and output leads, manufacturing cost is reduced and the overall package footprint on a mounting substrate is reduced. Further, the close proximity of the chips within the housing reduces phase differences among signals in the semiconductor chips.
    Type: Application
    Filed: December 13, 2002
    Publication date: June 17, 2004
    Applicant: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood, John Phillip Quinn
  • Patent number: 6740548
    Abstract: A semiconductor device is fabricated in a silicon on insulator (SOI) substrate including a supporting silicon substrate, a silicon oxide layer supported by the substrate, and a silicon layer overlying the silicon oxide layer. An electrical component is fabricated in the silicon layer over a portion of the silicon oxide layer, and then the substrate opposite from the component is masked and etched. A metal layer is then formed in the portion of the substrate which has been removed by etching with the metal layer providing heat removal from the component. In an alternative embodiment, the silicon oxide layer overlying the portion of the substrate is removed with the metal layer abutting the silicon layer. In fabricating the device, preferential etching is employed to remove the silicon in the substrate with the silicon oxide functioning as an etchant stop. A two step process can be employed including a first oxide etch to etch the bulk of the silicon and then a more selective but slower etch.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: May 25, 2004
    Assignee: Cree Microwave, Inc.
    Inventor: Johan Agus Darmawan
  • Patent number: 6737922
    Abstract: An RF power amplifier circuit for amplifying an RF signal over a broad range of power with improved efficiency includes a carrier amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power is disclosed. One or more peak amplifiers are connected in parallel with the carrier amplifier with each of the peak amplifiers being biased to sequentially provide an amplified output signal after the carrier amplifier approaches saturation. The input signal is applied through a signal splitter to the carrier amplifier and the plurality of peak amplifiers, and an output for receiving amplified output signals from the carrier amplifier and the plurality of peak amplifiers includes a resistive load R/2. The split input signal is applied through a 90° transformer to the carrier amplifier, and the outputs of the peak amplifiers are applied through 90° transformers to a output load.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: May 18, 2004
    Assignee: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood
  • Publication number: 20040085132
    Abstract: The linearity of a transistor amplifier comprising a plurality of transistors operating parallel is improved by reducing the odd order transconductance derivatives of signals generated by the transistors. The transistors can be provided in groups with each group having a different bias voltage applied thereto or each group of transistors can have a different input signal applied thereto. The groups of transistors can have different physical parameters such as the width to length ratio of gates in field effect transistors and threshold voltages for the transistors.
    Type: Application
    Filed: November 6, 2002
    Publication date: May 6, 2004
    Applicant: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood, John Phillip Quinn
  • Patent number: 6720228
    Abstract: A current mirror bias circuit for an RF amplifier transistor is modified whereby the reference transistor of the current mirror tracks hot carrier degradation in the RF transistor. Gate bias to the current mirror transistor is modified whereby the drain-to-gate voltage can be positive, and the lightly doped drain region in the lateral n-channel reference transistor is shortened and dopant concentration increased to increase the electric field of the reference transistor to provide the hot carrier injection degradation characteristics similar to the main transistor. Additionally, the gate length of the reference transistor can be shortened to effect the hot carrier injection degradation.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: April 13, 2004
    Assignee: Cree Microwave, Inc.
    Inventors: John F. Sevic, Francois Hebert
  • Publication number: 20040061214
    Abstract: The linearity of a wideband RF power transistor amplifier is improved by including output matching circuit and an integrated bias/RF diplexer with RF and video bypassing capacitor network within the transistor package and connected directly to the transistor. By placing the RF and video bypass power supply circuitry within the package and close to the transistor, the input impedance resonance can be increased from approximately 50 MHz to over 125 MHz, thereby reducing AM/PM distortion in the output signal.
    Type: Application
    Filed: September 30, 2002
    Publication date: April 1, 2004
    Applicant: Cree Microwave, Inc.
    Inventor: Emil James Crescenzi
  • Patent number: 6700444
    Abstract: An RF power amplifier for amplifying an RF signal over a broad range of power with improved efficiency includes a main amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power. A plurality of auxiliary amplifiers are connected in parallel with the main amplifier with each of the auxiliary amplifiers being biased to sequentially provide an amplified output signal after the main amplifier approaches saturation. The input signal is applied through a signal splitter to the main amplifier and the plurality of auxiliary amplifiers, and an output for receiving amplified output signals from the main amplifier and the plurality of auxiliary amplifiers includes a resistive load R/2. The split input signal is applied through a 90° transformer to the main amplifier, and the outputs of the auxiliary amplifiers are applied through 90° transformers to a output load.
    Type: Grant
    Filed: January 28, 2002
    Date of Patent: March 2, 2004
    Assignee: Cree Microwave, Inc.
    Inventor: Raymond Sydney Pengelly
  • Publication number: 20030210096
    Abstract: An RF power amplifier circuit for amplifying an RF signal over a broad range of power with improved efficiency includes a carrier amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power is disclosed. A plurality of peak amplifiers are connected in parallel with the carrier amplifier with each of the peak amplifiers being biased to sequentially provide an amplified output signal after the carrier amplifier approaches saturation. The input signal is applied through a signal splitter to the carrier amplifier and the plurality of peak amplifiers, and an output for receiving amplified output signals from the carrier amplifier and the plurality of peak amplifiers includes a resistive load R/2. The split input signal is applied through a 90° transformer to the carrier amplifier, and the outputs of the peak amplifiers are applied through 90° transformers to a output load.
    Type: Application
    Filed: May 5, 2003
    Publication date: November 13, 2003
    Applicant: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood
  • Publication number: 20030201833
    Abstract: An RF power amplifier circuit for amplifying an RF signal over a broad range of power with improved efficiency includes a carrier amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power is disclosed. One or more peak amplifiers are connected in parallel with the carrier amplifier with each of the peak amplifiers being biased to sequentially provide an amplified output signal after the carrier amplifier approaches saturation. The input signal is applied through a signal splitter to the carrier amplifier and the plurality of peak amplifiers, and an output for receiving amplified output signals from the carrier amplifier and the plurality of peak amplifiers includes a resistive load R/2. The split input signal is applied through a 90° transformer to the carrier amplifier, and the outputs of the peak amplifiers are applied through 90° transformers to a output load.
    Type: Application
    Filed: May 5, 2003
    Publication date: October 30, 2003
    Applicant: Cree Microwave, Inc.
    Inventors: Raymond Sydney Pengelly, Simon Maurice Wood
  • Publication number: 20030107084
    Abstract: A semiconductor device is fabricated in a silicon on insulator (SOI) substrate including a supporting silicon substrate, a silicon oxide layer supported by the substrate, and a silicon layer overlying the silicon oxide layer. An electrical component is fabricated in the silicon layer over a portion of the silicon oxide layer, and then the substrate opposite from the component is masked and etched. A metal layer is then formed in the portion of the substrate which has been removed by etching with the metal layer providing heat removal from the component. In an alternative embodiment, the silicon oxide layer overlying the portion of the substrate is removed with the metal layer abutting the silicon layer. In fabricating the device, preferential etching is employed to remove the silicon in the substrate with the silicon oxide functioning as an etchant stop. A two step process can be employed including a first oxide etch to etch the bulk of the silicon and then a more selective but slower etch.
    Type: Application
    Filed: December 20, 2002
    Publication date: June 12, 2003
    Applicant: Cree Microwave, Inc.
    Inventor: Johan Agus Darmawan