Patents by Inventor Chettan Babla

Chettan Babla 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: 6226509
    Abstract: To reduce the impact of image frequencies generated by mixing an incident carrier signal down to a relatively low intermediate frequency signal used in subsequent signal processing, a mixing frequency is selected such that the generated intermediate frequency signal has a frequency offset relative to DC that is substantially that of a single channel spacing between frequency adjacent incident carrier signals, as shown in FIG. 2. Image rejection is further improved through the integration of a current-driven polyphase filter (36) directly between an input stage (Q1 to Q4) and a mixer stage (Q5 to Q12) of an image reject mixer (FIG. 4) such as to mitigate quadrature divergence between separate in-phase and quadrature paths within the image reject mixer.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: May 1, 2001
    Assignee: Nortel Networks Limited
    Inventors: Peter John Mole, Henric Van Vliet, Chettan Babla