Patents by Inventor Roger G. Roberts

Roger G. Roberts 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: 5955998
    Abstract: A ferrite scanning line source is formed of a ferrite toroid and one or more dielectric slabs mounted to a side of the toroid. A signal propagating through the waveguide is phase shifted by the magnetization of the toroid. The further down the toroid the signal propagates the greater the phase shift that is applied to the signal. Radiators or coupling ports are formed by slots cut in a wall of the waveguide. The phase of the signal radiating from each slot in the line source is shifted from the signals emanating from the preceding and following slot in the line source. By properly locating the slots along the line source, a composite beam formed by the energy radiating from each slot may be titled (scanned) to a desired direction. In addition, the amount of phase shift applied to the signal by the waveguide depends on the magnetic state of the phase shifter.
    Type: Grant
    Filed: January 5, 1996
    Date of Patent: September 21, 1999
    Assignee: EMS Technologies, Inc.
    Inventors: Roger G. Roberts, Wyman L. Williams, Jeff M. Alexander
  • Patent number: 5456884
    Abstract: A mechanism is provided for loading the cassette into an operative relationship with a machine for dispensing contents of the cassette for use by the machine. The loading mechanism includes a base adapted for being fixedly mounted on the machine. The loading mechanism also includes a holder for releasably holding the cassette. The holder has one end pivotally connected to the base for pivoting about an axis for moving the cassette between a first position at which the holder releasably receives the cassette and a second position at which the cassette is placed in an operative relationship with the machine. The loading mechanism further includes a linkage mechanism coupled between the base and the holder for translating the holder along the axis as the holder is pivoted between the first and second positions.
    Type: Grant
    Filed: June 14, 1994
    Date of Patent: October 10, 1995
    Assignee: Akzo Nobel N.V.
    Inventors: Gregory D. Lewis, Roger G. Roberts, Thomas B. Givens
  • Patent number: 5364592
    Abstract: A cassette for storing and dispensing cuvettes and comprising an enclosable frame defining an interior volume for storing cuvettes. The frame includes a removable cover to aid in loading a plurality of cuvettes into the cassette. The frame also includes a side wall having a pivotally mounted door for pivoting between a closed position and an open position for dispensing the cuvettes from the cassette. And, the frame includes a locking mechanism for locking the door in the closed position to avoid an inadvertent dispensing of cuvettes. According to another aspect of the invention, a mechanism is provided for loading the cassette into an operative relationship with a machine for dispensing contents of the cassette for use by the machine. The loading mechanism includes a base adapted for being fixedly mounted on the machine. The loading mechanism also includes a holder for releasably holding the cassette.
    Type: Grant
    Filed: July 22, 1992
    Date of Patent: November 15, 1994
    Assignee: Akzo N.V.
    Inventors: Gregory D. Lewis, Roger G. Roberts, Thomas B. Givens
  • Patent number: 5304999
    Abstract: A 90.degree. coupling circuit cascaded with a pair of hybrid mode latchable phase shifters provides polarization agility for an RF radiator module of the type typically used in a phased array. For example, such radiator modules typically may utilize an active microwave integrated circuit (MIC), a monolithic microwave integrated circuit (MMIC) or a passive reciprocal hybrid mode element (RHYME) circuit. These circuits are arranged to provide duplex RF transmit/receive functions with controllable phase shifts at each radiator site in a phased array. By appropriately setting the two controllable phase shifters to different combinations of phase shifts (e.g., 0.degree. and/or 90.degree.) to a dual orthogonal mode radiator, different spatial polarizations for RF radiator transmit/receive functions can be defined. The radiator itself may include a square or circular waveguide including, in some cases, a reciprocal dielectric quarter-wave plate and a non-reciprocal ferrite quarter-wave plate.
    Type: Grant
    Filed: November 20, 1991
    Date of Patent: April 19, 1994
    Assignee: Electromagnetic Sciences, Inc.
    Inventors: Roger G. Roberts, Thomas E. Sharon
  • Patent number: 5302958
    Abstract: A low loss, fast switching, electronically tunable filter circuit which is microstrip compatible is obtained through the use of a resonant ring structure having two couplers, a low noise amplifier and a variable phase shifter. The tunable filter may advantageously be used in the receive channel of a transmit/receive module for phased arrays wherein the resonant frequency of the ring can be tuned anywhere in the operating frequency range so as to increase the dynamic range of the receiver.
    Type: Grant
    Filed: August 14, 1992
    Date of Patent: April 12, 1994
    Assignee: EMS Technologies, Inc.
    Inventors: Roger G. Roberts, Paul R. Cox
  • Patent number: 5170138
    Abstract: A miniaturized waveguide mode ferrite RF phase shifter is efficiently transitioned to a matched impedance microstrip transmission line mode at either end to result in an ultra small, efficient and lightweight essentially "planar" phase shifter device having a single ferrimagnetic toroid.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: December 8, 1992
    Assignee: Electromagnetic Sciences, Inc.
    Inventors: Roger G. Roberts, Thomas E. Sharon
  • Patent number: 5144319
    Abstract: An RF phase shifter combines a non-reciprocal ferrite 180.degree. stage with one or more reciprocal diode phase shifting stages to produce an essentially planar phase shifter that is ultra small, efficient and lightweight. Such phase shifter elements may be used in phased arrays to produce an array offering major improvements over existing planar substrate all diode phase shifters while maintaining the phase gradient between array elements and without switching the ferrite shifter between the transmit and receive modes.
    Type: Grant
    Filed: March 14, 1991
    Date of Patent: September 1, 1992
    Assignee: Electromagnetic Sciences, Inc.
    Inventor: Roger G. Roberts
  • Patent number: 5129099
    Abstract: A reciprocal transceiver to radiator coupling circuit uses both microstrip and waveguide modes of RF signal transmission (including a pair of nonreciprocal hybrid mode phase shifters) to gain size and weight advantages useful in feeding large scale phase arrays. At the same time, the radar cross section of such array apertures is reduced by arranging separate nonreciprocal receive and transmit branches of the circuit to route spurious intra-circuit reflections of incoming RF signals to a matched termination.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: July 7, 1992
    Assignee: Electromagnetic Sciences, Inc.
    Inventor: Roger G. Roberts
  • Patent number: 5075648
    Abstract: A miniaturized waveguide mode ferrite RF phase shifter is efficiently transitioned to a matched impedance microstrip transmission line mode at either end to result in an ultra small, efficient and lightweight essentially "planar" phase shifter device having wide application in the microwave industry.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: December 24, 1991
    Assignee: Electromagnetic Sciences, Inc.
    Inventors: Roger G. Roberts, Jeff M. Alexander, James P. Montgomery
  • Patent number: 4445098
    Abstract: The present invention is for an apparatus and method of fast-switching a dual-toroid microwave ferrite phase shifter. A first circuit is provided for controllably switching the ferrite in one of the toroids between a saturated and partially saturated states. A second conduit is provided for controllably switching the ferrite in the other of the toroids between a saturated and partially saturated states. A control circuit is provided for controlling the first and second circuits such that the ferrite in at least one of the toroids is maintained in the saturated state at any given time such that any desired phase shift may be achieved with only one switching operation for each toroid. The present invention provides new reference states such that there are two reciprocal phase states for any given phase state such that a reciprocal phase state may always be achieved with only one switching operation for each toroid.
    Type: Grant
    Filed: February 19, 1982
    Date of Patent: April 24, 1984
    Assignee: Electromagnetic Sciences, Inc.
    Inventors: Thomas E. Sharon, Roger G. Roberts