Patents Represented by Attorney, Agent or Law Firm Frances I. Gray
  • Patent number: 6608475
    Abstract: A network analyzer using time sequenced measurements has a pair of switches for isolating respective mixers from a local oscillator source to ease problems caused by direct leakage from the signal source. The signal source is set to a desired measurement frequency and a local oscillator is set to a desired frequency so that, when mixed, a desired IF frequency is achieved. The signal source output is applied to a return loss bridge, to which also is coupled a device under test, and to a reference channel mixer. A return loss signal from the return loss bridge is applied to a test channel mixer. The LO output is applied in a time sequence via an LO switch first to the reference channel mixer and then to the test channel mixer. An output switch couples the respective mixers to a processor in the same time sequence to provide sequential measurements of magnitude and phase from which reflection coefficients are derived for the device under test.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: August 19, 2003
    Assignee: Tektronix, Inc.
    Inventor: Linley F. Gumm
  • Patent number: 6056394
    Abstract: A solid ink stick feed system for use in a color printer is disclosed that utilizes a plurality of ink stick feed receptacles in an ink stick feed bin of predetermined shapes corresponding to the plurality of shapes of the ink sticks such that an incorrectly matched ink stick shape or incorrectly oriented ink stick is retained in a raised position to indicate to the printer operator that the ink stick should be removed and to facilitate grasping and removing such ink stick.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: May 2, 2000
    Assignee: Tektronix, Inc.
    Inventors: Gerard H. Rousseau, Brent R. Jones, David W. Johnson, John A. Wright