Patents by Inventor Tsuyoshi Momiyama

Tsuyoshi Momiyama 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).

  • Piezoelectric ceramic filter circuit and piezoelectric ceramic filter
    Patent number: 5850166
    Abstract: Multiple piezoelectric ceramic filter elements have different center frequencies from each other and are cascade connected together. The piezoelectric ceramic filter elements satisfy the condition 0<.vertline.dF.sub.0 .vertline./BW.sub.3 <0.8; where .vertline.dF.sub.0 .vertline. is the absolute value of the frequency difference dF.sub.0 between the center frequencies, and BW.sub.3 is the band width of each piezoelectric ceramic filter element in which the amplitude loss is 3 dB or less. A low insertion loss and an improvement in the group delay characteristics are compatible at the same time.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: December 15, 1998
    Assignee: TDK Corporation
    Inventors: Ikuo Katoh, Tsuyoshi Momiyama