Patents by Inventor Andrew C. Callahan

Andrew C. Callahan 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: 4170766
    Abstract: A beamformer forms a beam from a set of samples of signals from an array of elements such as sonar transducers. Sequences of signal samples from each transducer are delayed relative to each other by fractional amounts of the intersample interval. The sequences of the signal samples with the predetermined delays therebetween are applied to a common beamforming filter having a pass band of sufficient width to accommodate the signals. The impulse response time of the filter is longer than the intersample interval in any one of the sample sequences for providing a beam equal to the sum of regenerated transducer signals. The radiation pattern of the beam is independent of the sampling rate.
    Type: Grant
    Filed: January 27, 1978
    Date of Patent: October 9, 1979
    Assignee: Raytheon Company
    Inventors: Roger G. Pridham, Andrew C. Callahan, Ronald A. Mucci