Patents by Inventor Stephen E. Krafft

Stephen E. Krafft 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: 8369816
    Abstract: According to one exemplary embodiment, a selectable notch filter includes a transmission line, a bias circuit, and a switch for selectably coupling the transmission line to ground. In one embodiment, the switch is a PIN diode. The selectable notch filter can selectably suppress a first frequency from being output when the transmission line is coupled to ground. Additionally, the selectable notch filter can selectably suppress a second frequency from being output when the transmission line is not coupled to ground. In one embodiment, the first frequency is approximately equal to a multiple of two of the second frequency. In one embodiment, the selectable notch filter can utilize more than one transmission line.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: February 5, 2013
    Assignee: Broadcom Corporation
    Inventors: Lukose Ninan, Stephen E. Krafft
  • Publication number: 20090295502
    Abstract: According to one exemplary embodiment, a selectable notch filter includes a transmission line, a bias circuit, and a switch for selectably coupling the transmission line to ground. In one embodiment, the switch is a PIN diode. The selectable notch filter can selectably suppress a first frequency from being output when the transmission line is coupled to ground. Additionally, the selectable notch filter can selectably suppress a second frequency from being output when the transmission line is not coupled to ground. In one embodiment, the first frequency is approximately equal to a multiple of two of the second frequency. In one embodiment, the selectable notch filter can utilize more than one transmission line.
    Type: Application
    Filed: August 3, 2009
    Publication date: December 3, 2009
    Inventors: Lukose Ninan, Stephen E. Krafft
  • Patent number: 7589604
    Abstract: According to one exemplary embodiment, a selectable notch filter includes a transmission line, a bias circuit, and a switch for selectably coupling the transmission line to ground. In one embodiment, the switch is a PIN diode. The selectable notch filter can selectably suppress a first frequency from being output when the transmission line is coupled to ground. Additionally, the selectable notch filter can selectably suppress a second frequency from being output when the transmission line is not coupled to ground. In one embodiment, the first frequency is approximately equal to a multiple of two of the second frequency. In one embodiment, the selectable notch filter can utilize more than one transmission line.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: September 15, 2009
    Assignee: Broadcom Corporation
    Inventors: Lukose Ninan, Stephen E. Krafft
  • Publication number: 20080129421
    Abstract: According to one exemplary embodiment, a selectable notch filter includes a transmission line, a bias circuit, and a switch for selectably coupling the transmission line to ground. In one embodiment, the switch is a PIN diode. The selectable notch filter can selectably suppress a first frequency from being output when the transmission line is coupled to ground. Additionally, the selectable notch filter can selectably suppress a second frequency from being output when the transmission line is not coupled to ground. In one embodiment, the first frequency is approximately equal to a multiple of two of the second frequency. In one embodiment, the selectable notch filter can utilize more than one transmission line.
    Type: Application
    Filed: December 1, 2006
    Publication date: June 5, 2008
    Inventors: Lukose Ninan, Stephen E. Krafft
  • Patent number: 7327819
    Abstract: A carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system. In-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.
    Type: Grant
    Filed: October 16, 2003
    Date of Patent: February 5, 2008
    Assignee: Broadcom Corporation
    Inventors: Thuji S. Lin, Tian-Min Liu, Stephen E. Krafft
  • Publication number: 20040081257
    Abstract: Improved carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system are disclosed. Carrier and phase recovery systems operate on complex signals representing symbols having the same time stamp for each phase error term. in-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded in a decision device to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.
    Type: Application
    Filed: October 16, 2003
    Publication date: April 29, 2004
    Applicant: Broadcom Corporation
    Inventors: Thuji S. Lin, Tian-Min Liu, Stephen E. Krafft
  • Patent number: 6671342
    Abstract: Improved carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system are disclosed. Carrier and phase recovery systems operate on complex signals representing symbols having the same time stamp for each phase error term. in-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded in a decision device to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: December 30, 2003
    Assignee: Broadcom Corporation
    Inventors: Thuji S. Lin, Tian-Min Liu, Stephen E. Krafft
  • Publication number: 20030058967
    Abstract: Improved carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system are disclosed. Carrier and phase recovery systems operate on complex signals representing symbols having the same time stamp for each phase error term. in-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded in a decision device to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.
    Type: Application
    Filed: November 6, 2002
    Publication date: March 27, 2003
    Applicant: Broadcom Corporation
    Inventors: Thuji S. Lin, Tian-Min Liu, Stephen E. Krafft
  • Patent number: 6493409
    Abstract: Improved carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system are disclosed. Carrier and phase recovery systems operate on complex signals representing symbols having the same time stamp for each phase error term. in-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded in a decision device to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: December 10, 2002
    Assignee: Broadcom Corporation
    Inventors: Thuji S. Lin, Tian-Min Liu, Stephen E. Krafft