Patents by Inventor Eric B. Rodal

Eric B. Rodal 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: 5592173
    Abstract: A GPS receiver having a normal mode to receive GPS satellite signals and to provide location information, and a low power standby mode. A microprocessor system in the GPS receiver causes the GPS receiver to alternate between the normal mode and the low power standby mode in order to reduce the average power consumption in the GPS receiver. In the normal mode a GPS antenna receives GPS satellite signals, the GPS frequency downconverter converts the frequency of the GPS satellite signals to an intermediate frequency, a digital signal processing system processes the intermediate frequency to provide GPS satellite signal correlation information. The microprocessor system processes the correlation information and provides location information to a user. In the standby mode, the operating power is inhibited in the GPS antenna and the GPS frequency downconverter, the system clock is inhibited in the digital processing system, and the microprocessor clock is inhibited in the microprocessor system.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: January 7, 1997
    Assignee: Trimble Navigation, Ltd
    Inventors: Chung Y. Lau, Dominic G. Farmer, Kreg A. Martin, Eric B. Rodal
  • Patent number: 5564098
    Abstract: A GPS receiver downconverter combines on a single integrated circuit, a first super-heterodyne mixer, a voltage controlled oscillator, a phase locked loop, a pair of quadrature mixers and a pair of quantizers with in-phase and quadrature-phase sampler outputs operable at twenty-five MHz and 2.5 MHz. Emitter-coupled logic and special low-voltage bipolar semiconductor technology are combined for 3.3 volt operation at under one hundred milliwatts.
    Type: Grant
    Filed: September 13, 1994
    Date of Patent: October 8, 1996
    Assignee: Trimble Navigation Limited
    Inventors: Eric B. Rodal, Gary L. Wagner, Chung Y. Lau
  • Patent number: 5521610
    Abstract: An antenna system embodiment of the present invention comprises a curved dipole antenna stood off at its center by a printed circuit board assembly containing a pre-amplifier. The curved dipole antenna is implemented with a single-sided flexible circuit and is anchored at its four free ends to a sheet metal base for a groundplane. The printed circuit board assembly containing the predetermined amplifier is fixed perpendicular to the sheet metal base and has a tab that engages a slot in the center of the single-sided flexible circuit for electrical connection of a pair of orthogonal dipoles patterned on one side of the flexible circuit.
    Type: Grant
    Filed: April 26, 1995
    Date of Patent: May 28, 1996
    Assignee: Trimble Navigation Limited
    Inventor: Eric B. Rodal
  • Patent number: 5467095
    Abstract: An antenna has a ground plane and a radiating element supported in electrically insulated, closely spaced-apart relation to the ground plane. Electrical energy is fed to the radiating element for radiation therefrom. The radiating element is constructed so as to lengthen at least one effective electrical dimension of the radiating element relative to a corresponding dimension of an orthogonal projection of the radiating element onto a plane parallel to the ground plane. In the preferred embodiment, the radiating element has a central plane portion substantially parallel to the ground plane, an outer flange portion extending towards the ground plane, and a square cutout centered with respect to the central plane portion.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: November 14, 1995
    Inventors: Eric B. Rodal, Reed A. Parker
  • Patent number: 5408193
    Abstract: An embodiment of the present invention comprises a series pass transistor with its emitter arranged to receive a source of DC power, its collector arranged to supply a DC load, and its base connected to the junction of a capacitor to ground and an inductor to the collector. An output capacitor from the collector to ground is alternatively included. In a second embodiment of the present invention, an operational amplifier is inserted in the base circuit to increase the effective circuit gain.
    Type: Grant
    Filed: September 3, 1993
    Date of Patent: April 18, 1995
    Assignee: Trimble Navigation Limited
    Inventor: Eric B. Rodal
  • Patent number: 5187450
    Abstract: An embodiment of the present invention is a voltage controlled oscillator (VCO) comprised of a differential pair of transistors that have respective positive feedback paths with phase-lead networks cross-coupled. Each positive feedback path on each side has two different phase-lead branches. The two phase-lead branches have the same phase differences on each side of the differential pair, in order to maintain a symmetry that improves common-mode noise rejection on a voltage control differential input. Current-steering is used to control the mixture of currents that arrive at the bases of the differential transistor pair from the respective two different phase-lead branches, and thereby changing the frequency of the VCO.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: February 16, 1993
    Assignee: Trimble Navigation Limited
    Inventors: Gary L. Wagner, Eric B. Rodal, Chung Y. Lau
  • Patent number: 5173715
    Abstract: An antenna comprises a base plate forming a ground plane, a coaxial feed serving as a mast connected to the base plate and extending along an axis that is normal to the ground plane, and two orthogonal dipoles each formed of two elements. Each dipole element has a first end connected to and supported by the mast at a first location spaced apart from the ground plane by a predetermined distance and a second end closer to the ground plane and exhibits a curvature in a plane containing the mast.
    Type: Grant
    Filed: June 12, 1991
    Date of Patent: December 22, 1992
    Assignee: Trimble Navigation
    Inventors: Eric B. Rodal, Michael C. Detro, David R. Gildea, James M. Janky