Patents by Inventor Robert K. Griffith

Robert K. Griffith 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: 6121854
    Abstract: A power divider includes an input port, a first output port, a second output port, a first transformer coupled between the input port and the first output port, and a second transformer coupled between the input port and the second output port. The first and second transformers each incorporates a low pass filter. The power divider further includes a ground plate disposed adjacent to the first and second transformers. The ground plate is capacitively coupled to the low pass filters of the first and second transformers for enhancing the low pass filtering characteristics of the power divider. The power divider provides low pass filtering capability while achieving a significant size reduction over conventional power dividers.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: September 19, 2000
    Assignee: Digital Microwave Corporation
    Inventors: Robert K. Griffith, Roland Matian
  • Patent number: 5808528
    Abstract: An inductive strip waveguide band-pass filter includes a conductive movable wall which can be set to various positions to allow a varying "A" dimension, thereby setting controllably the center frequency of the filter over a predetermined range. If the inductive strip filter includes multiple synchronized resonant cavities, the resonant cavities remain synchronized for all positions of the movable wall. The position of the movable wall can be set manually or by a motorized control mechanism.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: September 15, 1998
    Assignee: Digital Microwave Corporation
    Inventors: Robert K. Griffith, Craig R. Solis, Cheyenne M. Noda, William F. Melody
  • Patent number: 4677400
    Abstract: A variable line extender for wave guide comprising an elongated electrically conductive housing member and an electrically conductive slide member, the slide member having a convex shaped rounded end and a U-shaped recess extending transversely continuously from one end of the slide longitudinally along one side thereof, around the rounded end, and then along the other side back to the first end, with said housing having a pair of wave guide shaped ports in register with the U-shaped recess of the slide member. Means are provided for adjusting the relative longitudinal position of the slide with respect to the housing so as to vary the length of the path between the ports.
    Type: Grant
    Filed: April 8, 1985
    Date of Patent: June 30, 1987
    Assignee: Honeywell Inc.
    Inventors: Robert K. Griffith, T. Norman Hardy, Edley V. McKnight, Vladimir K. Vavra
  • Patent number: 4652556
    Abstract: Compounds of the formula: ##STR1## wherein R is aryl of 6 to 12 carbon atoms or aralkyl of 7 to 14 carbon atoms either optionally substituted with 1 to 3 substituents independently selected from lower alkyl of 1 to 6 carbon atoms, lower alkoxy of 1 to 6 carbon atoms, lower alkylthio of 1 to 6 carbon atoms, lower alkylsulfinyl of 1 to 6 carbon atoms, lower alkylsulfonyl of 1 to 6 carbon atoms, halogen, trihalomethyl, nitro, cyano or carboxyl; alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 10 carbon atoms, lower alkenyl of 2 to 6 carbon atoms, or lower alkynyl of 2 to 6 carbon atoms, all optionally substituted with 1 to 3 halogen atoms; lower alkoxyalkylene; lower alkylene carbalkoxy; lower alkylthioalkylene; lower alkylsulfinylalkylene; or lower alkylsulfonylalkylene; R.sup.1 and R.sup.2 are independently hydrogen, lower alkyl of 1 to 6 carbon atoms, aryl of 6 to 12 carbon atoms, or thienyl, or taken together form an alkylene bridge to give a cycloalkyl group of 3 to 10 carbon atoms; and R.sup.
    Type: Grant
    Filed: August 19, 1985
    Date of Patent: March 24, 1987
    Assignee: Chevron Research Company
    Inventors: Joseph E. Moore, Yuh-Lin Yang, Robert K. Griffith, David C. K. Chan