Patents by Inventor Eric M. Mullen

Eric M. Mullen 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: 7626474
    Abstract: An attenuator circuit. The attenuator circuit includes a resistive divider coupled to a capacitive network including first and second capacitive dividers. The resistive divider is configured to perform an N:1 attenuation of a signal in a low frequency range. The first and second capacitive dividers are configured to perform an N:1 attenuation in the high frequency range that is a product of the attenuation provided by each (e.g., each performing an M:1 attenuation, where N=M×M, with the total attenuation of the capacitive dividers being N:1 where N=M×M). A variable capacitance divider is coupled in parallel with the second capacitive divider, and includes first and second variable capacitors that, when adjusted, change the high frequency attenuation of the attenuator circuit to match the value of the high frequency attenuation to that of the low frequency attenuation.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: December 1, 2009
    Assignee: National Instruments Corporation
    Inventors: Eric M. Mullen, Mark Whittington
  • Publication number: 20090231069
    Abstract: An attenuator circuit. The attenuator circuit includes a resistive divider coupled to a capacitive network including first and second capacitive dividers. The resistive divider is configured to perform an N:1 attenuation of a signal in a low frequency range. The first and second capacitive dividers are configured to perform an N:1 attenuation in the high frequency range that is a product of the attenuation provided by each (e.g., each performing an M:1 attenuation, where N=M×M, with the total attenuation of the capacitive dividers being N:1 where N=M×M). A variable capacitance divider is coupled in parallel with the second capacitive divider, and includes first and second variable capacitors that, when adjusted, change the high frequency attenuation of the attenuator circuit to match the value of the high frequency attenuation to that of the low frequency attenuation.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 17, 2009
    Inventors: Eric M. Mullen, Mark Whittington