Patents by Inventor Joseph Frenna

Joseph Frenna 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).

  • Odd order elliptic waveguide cavity filters
    Patent number: 4644305
    Abstract: An odd order bandpass filter has at least one cavity resonating at its resonant frequency in three independent orthogonal modes. The filter has at least one feedback coupling that is made to resonate and change sign at a center frequency. When the filter has two cavities, one being a triple cavity and the other being a dual mode cavity, the filter can be operated to achieve an elliptic function response. Also, the filter of the present invention can achieve a weight and volume reduction when compared to six-pole dual mode filters.
    Type: Grant
    Filed: December 3, 1985
    Date of Patent: February 17, 1987
    Assignee: Com Dev. Ltd.
    Inventors: Wai-Cheung Tang, Joseph Frenna, David Siu