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).
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Patent number: 10181388Abstract: 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: GrantFiled: October 20, 2017Date of Patent: January 15, 2019Assignee: THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE AIR FORCEInventor: Brad W. Hoff
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Patent number: 10109447Abstract: 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: GrantFiled: May 31, 2018Date of Patent: October 23, 2018Assignee: The United States of America as Represented by the Secretary of the Air ForceInventors: Brad W. Hoff, David H. Simon, James A. Schrock
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Patent number: 9819320Abstract: 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: GrantFiled: January 24, 2017Date of Patent: November 14, 2017Assignee: The Government of the United States of America as Represented by the Secretary of the Air ForceInventors: Brad W. Hoff, David M. French
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Patent number: 9281809Abstract: 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: GrantFiled: May 10, 2012Date of Patent: March 8, 2016Assignee: The UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE AIR FORCEInventors: Brad W. Hoff, David Michael French, Susan L. Heidger
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Patent number: 8841867Abstract: 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: GrantFiled: August 20, 2010Date of Patent: September 23, 2014Assignee: The Regents of The University of MichiganInventors: Ronald M. Gilgenbach, Yue-Ying Lau, David M. French, Brad W. Hoff, John Luginsland, Matthew Franzi
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Patent number: 8766541Abstract: 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: GrantFiled: September 26, 2011Date of Patent: July 1, 2014Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Brad W. Hoff, David M. French, Donald A. Shiffler, Susan L. Heidger, Wilkin W. Tang
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Patent number: 8358190Abstract: 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: GrantFiled: September 26, 2011Date of Patent: January 22, 2013Assignee: The United States of America as Represented by the Secretary of the Air ForceInventors: Brad W. Hoff, Peter J. Mardahl, Christina H. Chen, John C. Horwath, Michael D. Haworth
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Publication number: 20110204785Abstract: 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: ApplicationFiled: August 20, 2010Publication date: August 25, 2011Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGANInventors: Ronald M. Gilgenbach, Yue-Ying Lau, David M. French, Brad W. Hoff, John Luginsland, Matthew Franzi