Patents by Inventor Desmond L. Murphy

Desmond L. Murphy 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).

  • Film resistors
    Patent number: 4563564
    Abstract: A resistor formed by a film of resistive material deposited on a dielectric substrate is trimmed by removing resistive material along a line such that the film is divided into at least two discrete areas, one, and only one, of which areas includes two terminal portions of the film.
    Type: Grant
    Filed: January 30, 1984
    Date of Patent: January 7, 1986
    Assignee: Tektronix, Inc.
    Inventors: Bret Ericsen, John C. Hastings, Desmond L. Murphy, Scott Jansen
  • Oscilloscope signal input circuit including an attenuator
    Patent number: 4525688
    Abstract: An improved signal input circuit suitable for use in wideband oscilloscopes includes a high impedance controllable attenuator stage.
    Type: Grant
    Filed: August 1, 1983
    Date of Patent: June 25, 1985
    Assignee: Tektronix, Inc.
    Inventors: Desmond L. Murphy, Warren K. Wimmer
  • Termination for high impedance attenuator
    Patent number: 4495458
    Abstract: A termination for high impedance attenuator to be connected to the input of such high impedance attenuator. The termination circuit includes a series combination of a termination resistor, a delay line and an inductor, thereby cancelling the negative reflection due to the capacitive element at the output of the attenuator while maintaining the overall input impedance constant over a wide frequency range.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: January 22, 1985
    Assignee: Tektronix
    Inventor: Desmond L. Murphy
  • Hybrid cascade attenuator
    Patent number: 4181903
    Abstract: A high-impedance cascade attenuator device includes a plurality of attenuator stages mounted on a single substrate by means of metallization and thick film processes. The attenuator stages are conventional frequency-compensated voltage dividers designed for high-frequency operation; however, the capacitive compensation is included in the thick film process, and the attenuator components may be trimmed to provide precise impedance ratios so that calibration or circuit adjustments are never required.
    Type: Grant
    Filed: February 14, 1978
    Date of Patent: January 1, 1980
    Assignee: Tektronix, Inc.
    Inventors: Kenneth C. Holland, Gary W. Reed, Desmond L. Murphy