Patents by Inventor Patrick A. Roman

Patrick A. Roman 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).

  • Impedance matched to vacuum, invisible edge, diffraction suppressed mirror
    Patent number: 9012008
    Abstract: Diffraction suppressed mirrors having an invisible edge are disclosed for incident light at both targeted wavelengths and broadband incident light. The mirrors have a first having at least one discontiguous portion having a plurality of nanostructured apertures. The discontiguous mirror portion impedance matches a relatively high impedance portion of the mirror to a relatively low impedance portion of the mirror, thereby reducing the diffraction edge effect otherwise present in a conventional mirror.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: April 21, 2015
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John G. Hagopian, Patrick A. Roman, Sharham Shiri, Edward J. Wollack
  • Ion source with corner cathode
    Patent number: 8134130
    Abstract: An ion source may include first, second, and third electrodes. The first electrode may be a repeller having a V-shaped groove. The second electrode may be an electron emitter filament disposed adjacent the base of the V-shaped groove. The third electrode may be an anode that defines an enclosed volume with an aperture formed therein adjacent the electron emitter filament. A potential of the first electrode may be less than a potential of the second electrode, and the potential of the second electrode may be less than a potential of the third electrode. A fourth electrode that is disposed between the electron emitter filament and the anode may be used to produce a more collimated electron beam.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: March 13, 2012
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Federico A. Herrero, Patrick A. Roman
  • ION SOURCE WITH CORNER CATHODE
    Publication number: 20120012746
    Abstract: An ion source may include first, second, and third electrodes. The first electrode may be a repeller having a V-shaped groove. The second electrode may be an electron emitter filament disposed adjacent the base of the V-shaped groove. The third electrode may be an anode that defines an enclosed volume with an aperture formed therein adjacent the electron emitter filament. A potential of the first electrode may be less than a potential of the second electrode, and the potential of the second electrode may be less than a potential of the third electrode. A fourth electrode that is disposed between the electron emitter filament and the anode may be used to produce a more collimated electron beam.
    Type: Application
    Filed: July 19, 2010
    Publication date: January 19, 2012
    Inventors: FEDERICO A. HERRERO, Patrick A. Roman