Patents by Inventor Nigel P. Johnson

Nigel P. Johnson 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).

  • Methods and apparatus for testing circuit boards
    Patent number: 5406209
    Abstract: In methods and apparatus for non-contact testing of an electronic circuit board at least one electromagnetic emission sensing probe is disposed a short distance from a circuit board under test, the circuit board is operated while sensing electromagnetic emission from a region of the circuit board near the probe, and a time domain representation of the sensed electromagnetic emission is developed. The time domain representation of the sensed electromagnetic emission is compared to a time domain representation of electromagnetic emission of a circuit board known to be operating properly. Preferably, an array of electric field sensing probes is used to sense emissions from several regions of the circuit board simultaneously, and time domain representations of the sensed electromagnetic emissions are simultaneously developed and compared to respective time domain representations of electromagnetic emissions from circuit boards known to be operating properly.
    Type: Grant
    Filed: February 4, 1993
    Date of Patent: April 11, 1995
    Assignee: Northern Telecom Limited
    Inventors: Nigel P. Johnson, Dan Leonida, Richard R. Goulette, Stanislus K. Xavier