Patents Assigned to SPG Ltd.
  • Patent number: 7521991
    Abstract: A filter includes an input and an output. First and second filter stages having respective stage inputs and stage outputs are connected in cascade between the input and the output. Each filter stage includes an amplifier having an amplifier input and an amplifier output and an inner feedback loop connecting the amplifier output to the amplifier input. An outer feedback loop connects the stage output of the second filter stage with the stage input of the first filter stage. The first and second filter stages and the outer feedback loop are arranged so that an s-space closed-loop transfer function of the filter includes two zeros and a single pole.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: April 21, 2009
    Assignee: SPG Ltd.
    Inventors: Ilan Saul Barak, Kobi Ben-Atar, Eric L Unruh