Patents by Inventor Ernest L. Walker

Ernest L. Walker 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: 4075582
    Abstract: A surface acoustic wave filter is provided having an input and an output transducer, each consisting of a pair of comb-like structures, wherein the electrodes or teeth are interleaved and are varied in length in accordance with a weighting function determined by the Fourier transformation of the respective transducer characteristic frequency response so as to each produce a pair of frequency passbands symmetrical about their characteristic frequency. The latter frequency passband of the input transducer has the same passband center frequency as the first frequency passband of the output transducer. The coincident passbands of said input and output transducers resulting in an output from the output transducer having the center frequency of the coincident passbands.
    Type: Grant
    Filed: June 14, 1976
    Date of Patent: February 21, 1978
    Assignee: International Business Machines Corporation
    Inventor: Ernest L. Walker
  • Patent number: 3985968
    Abstract: An acoustical wave filter is formed by depositing a pattern of interdigitated conductors which form a coding arrangement on a piezeoelectric crystal. Multiplex communication through the crystal is achieved by depositing input filters of differing configuration on the crystals, which separate channels by autocorrelation of a pulse code. A single output filter is provided to respond to the waves set up in the crystal by the input filters to transmit these waves to a single common conductor. Demultiplex is similarly done on a second crystal.
    Type: Grant
    Filed: January 9, 1975
    Date of Patent: October 12, 1976
    Assignee: International Business Machines Corporation
    Inventors: William K. Stelzenmuller, Ernest L. Walker