Patents by Inventor John I. Upshur

John I. Upshur 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: 5889821
    Abstract: A method and apparatus to enable high-quality digital transmissions to a satellite terminal operating in proximity to a radar source combines interleaving a sequence of channel symbols at a land station before transmission of an RF signal to a satellite, increasing the satellite's EIRP to compensate for the effects of the radar's duty factor on received signal power and code distance, detecting the radar pulses at a satellite terminal, blanking the received RF signal to prevent reception of the signal by the modem at the satellite terminal during the radar's ON time, having the modem recognize and eliminate the effect of the gap in the channel signals on its metric calculation, and de-interleaving the sequence of channel symbols. As a result, satellite terminals operating in proximity to radar sources can provide the same quality of service as if there were no radars operating.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: March 30, 1999
    Assignee: Comsat Corporation
    Inventors: Donald S. Arnstein, Francois Assal, Moshe Lieberman, John I. Upshur
  • Patent number: 5119050
    Abstract: A low loss reflection-type analog phase shifter circuit producing a large range (nearly 360.degree.) of phase shift at X-band while achieving low attenuation (insertion loss) and little amplitude variation over all phase states. The results are achieved, in part, by using a terminating impedance which includes parallel-connected hyperabrupt varactor diodes. The circuit is implemented readily in a monolithic microwave integrated circuit using GaAs.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: June 2, 1992
    Inventors: John I. Upshur, Bernard D. Geller