Patents by Inventor John J. Gropelli, Jr.

John J. Gropelli, Jr. 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).

  • Quadrifilar helix antenna tuning using pin diodes
    Patent number: 4554554
    Abstract: An antenna is tuned in separate discrete frequency bands by changing the ctrical length of the antenna. PIN diodes are placed at predetermined locations on the antenna coaxial cable radiating elements. When it is desired to shorten the antenna for a higher frequency band use, the diodes are biased short circuiting segments of the antenna. When the lower frequency band use is desired, diodes are unbiased so that the diodes act like a very small capacitance shunted by a large resistance which is essentially an open circuit permitting the entire length of the antenna to operate.
    Type: Grant
    Filed: September 2, 1983
    Date of Patent: November 19, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Ralph C. Olesen, Robert A. Sainati, John J. Gropelli, Jr., Andrew J. Stanland