Selective Type Signal Filtering (e.g., From Low Pass To High Pass, Etc.) Patents (Class 327/555)
  • Control system using harmonic filters
    Patent number: 5469087
    Abstract: A harmonic filter for active or adaptive noise attenuation control systems for obtaining the complex amplitude of a single harmonic component from a signal which contains one or more harmonic components.
    Type: Grant
    Filed: December 2, 1994
    Date of Patent: November 21, 1995
    Assignee: Noise Cancellation Technologies, Inc.
    Inventor: Graham P. Eatwell