Patents Assigned to Telefonaktiebolaget L.M. Dericsson
  • Patent number: 7023292
    Abstract: Polar modulators include a phase splitter, a controller, variable current sources, transistor circuits, and a combiner. The phase splitter splits a RF carrier signal into quadrature component signals that are 90 degrees out of phase with each other. The controller generates modulation control signals based on information that is to be transmitted. The variable current sources each generate a variable amplitude current signal based on a different one of the modulation control signals. Each of the transistor circuits amplify a different one of the quadrature component signals with a variable amplification based on the variable amplitude current signal from a different one of the variable current sources to generate an amplitude adjusted quadrature component signal. The combiner combines the amplitude adjusted quadrature component signals from each of the transistor circuits to generate a phase-modulated RF carrier output signal.
    Type: Grant
    Filed: December 17, 2003
    Date of Patent: April 4, 2006
    Assignee: Telefonaktiebolaget L.M. Dericsson
    Inventors: David R. Pehlke, Aristotele Hadjichristos