Patents by Inventor Brad W. Hoff

Brad W. Hoff 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: 10181388
    Abstract: A crossed field device for generating electromagnetic emissions includes an anode having a first slow-wave structure having a plurality of first vanes separated by cavities formed therebetween and a second slow-wave structure having a plurality of second vanes separated by cavities formed therebetween. At least one of the first vanes is laterally aligned with one of the second vanes. The first vanes are offset from the second vanes by an offset distance so that at least one of the first vanes is not laterally aligned with a second vane and at least one of the second vanes is not laterally aligned with a first vane. The device further includes a cathode disposed in a space located between first and second vanes. A magnetic element generates a magnetic field (B), which is oriented orthogonally to an electric field (E) formed by the anode and cathode to generate EM emissions.
    Type: Grant
    Filed: October 20, 2017
    Date of Patent: January 15, 2019
    Assignee: THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE AIR FORCE
    Inventor: Brad W. Hoff
  • Patent number: 10109447
    Abstract: An apparatus, system, and method for performing electron beam modulation includes an input pulser to provide an electromagnetic pulse; a radio frequency (RF) filter to filter the electromagnetic pulse; a nonlinear transmission line to receive the electromagnetic pulse, and generate a backward wave RF oscillation of a predetermined frequency to travel in a direction opposite that of the electromagnetic pulse; and an electron beam generating device including an anode and a cathode, the electron beam generating device to receive a combined electromagnetic pulse from the RF filter and the backward wave RF oscillation from the nonlinear transmission line to cause excitation of a modulated voltage between the anode and cathode, and to cause the electron beam generating device to emit an electron beam that is modulated at the predetermined frequency of the backward wave RF oscillation.
    Type: Grant
    Filed: May 31, 2018
    Date of Patent: October 23, 2018
    Assignee: The United States of America as Represented by the Secretary of the Air Force
    Inventors: Brad W. Hoff, David H. Simon, James A. Schrock
  • Patent number: 9819320
    Abstract: A coaxial amplifier having at least one electron beam is provided. The amplifier may include a conductive rod, a plurality of parallel discs on the rod, a cathode array for producing at least one electron beam. When a plurality of electron beams are formed they are arranged in an annular configuration around said rod and disks, and directed along said rod and coaxially thereof. A first waveguide may apply electromagnetic wave energy to one end of said disc and rod assembly to induce propagation of said energy along said assembly. A second waveguide may extract the amplified electromagnetic energy from the other end of the disc and rod assembly.
    Type: Grant
    Filed: January 24, 2017
    Date of Patent: November 14, 2017
    Assignee: The Government of the United States of America as Represented by the Secretary of the Air Force
    Inventors: Brad W. Hoff, David M. French
  • Patent number: 9281809
    Abstract: A dielectric-based nonlinear transmission line (NLTL) coupled to an adjacent waveguide. Energy in an input pulse to the nonlinear transmission line is concentrated into an electromagnetic shock or a series of soliton-like oscillations by the nonlinear properties of the NLTL. Energy from the electromagnetic shock or the soliton-like oscillations are transferred into the waveguide. A plate of the NLTL coupled to the waveguide can include an aperture or a series of apertures. Energy from the electromagnetic shock or the soliton-like oscillations can then be transferred into waveguide via an aperture or apertures in such a way that forward and/or backward guided electromagnetic waves are generated in the waveguide. The waveguide can contain at a nonlinear magnetic material, a dielectric material, a slow wave structure, or a metamaterial. The NLTL can include nonlinear dielectric elements such as a periodic array interspersed with linear dielectric elements.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: March 8, 2016
    Assignee: The UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE AIR FORCE
    Inventors: Brad W. Hoff, David Michael French, Susan L. Heidger
  • Patent number: 8841867
    Abstract: A crossed field device, such as a magnetron or crossed field amplifier, that includes a cathode, an anode, one or more magnetic elements, and one or more extraction elements. In one embodiment, the crossed field device includes an annular cathode and anode that are axially spaced from one another such that the device produces an axial electric (E) field and a radial magnetic (B) field. In another embodiment, the crossed field device includes an oval-shaped cathode and anode that are radially spaced from one another such that the device produces a radial electric (E) field and an axial magnetic (B) field. The crossed field device may produce electromagnetic (EM) emissions having a frequency ranging from megahertz (MHz) to terahertz (THz), and may be used in one of a number of different applications.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: September 23, 2014
    Assignee: The Regents of The University of Michigan
    Inventors: Ronald M. Gilgenbach, Yue-Ying Lau, David M. French, Brad W. Hoff, John Luginsland, Matthew Franzi
  • Patent number: 8766541
    Abstract: A method to modulate the density of an electron beam as it is emitted from a cathode, the method comprised of connecting a source of pulsed input power to the input end of a nonlinear transmission line and connecting the output end directly to the cathode of an electron beam diode by a direct electrical connection.
    Type: Grant
    Filed: September 26, 2011
    Date of Patent: July 1, 2014
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Brad W. Hoff, David M. French, Donald A. Shiffler, Susan L. Heidger, Wilkin W. Tang
  • Patent number: 8358190
    Abstract: A wide aperture permanent magnet structure which is useful in creating a highly uniform longitudinal or solenoidal magnetic field in the working region of the magnet and in which the aperture of the structure can be equal in cross-sectional area to the working region of the magnet. The geometry and magnetization direction of the constituent magnets are chosen to maximize the uniformity of the longitudinal or solenoidal magnetic field in the working region of the magnet while minimizing the overall volume and weight of the structure as well as eliminating the need for magnetic pole pieces made of iron or other high permeability materials. The invention can take the form of a cylindrical shell of permanent magnets to create a solenoidal magnetic field, or a parallel surface arrangement to create a longitudinal magnetic field.
    Type: Grant
    Filed: September 26, 2011
    Date of Patent: January 22, 2013
    Assignee: The United States of America as Represented by the Secretary of the Air Force
    Inventors: Brad W. Hoff, Peter J. Mardahl, Christina H. Chen, John C. Horwath, Michael D. Haworth
  • Publication number: 20110204785
    Abstract: A crossed field device, such as a magnetron or crossed field amplifier, that includes a cathode, an anode, one or more magnetic elements, and one or more extraction elements. In one embodiment, the crossed field device includes an annular cathode and anode that are axially spaced from one another such that the device produces an axial electric (E) field and a radial magnetic (B) field. In another embodiment, the crossed field device includes an oval-shaped cathode and anode that are radially spaced from one another such that the device produces a radial electric (E) field and an axial magnetic (B) field. The crossed field device may produce electromagnetic (EM) emissions having a frequency ranging from megahertz (MHz) to terahertz (THz), and may be used in one of a number of different applications.
    Type: Application
    Filed: August 20, 2010
    Publication date: August 25, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGAN
    Inventors: Ronald M. Gilgenbach, Yue-Ying Lau, David M. French, Brad W. Hoff, John Luginsland, Matthew Franzi