Patents by Inventor Eijiro Oshitani

Eijiro Oshitani 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: 4403347
    Abstract: An improved antenna tuning circuit for a long and a medium wave AM radio receiver is disclosed. The antenna tuning circuit of the present invention comprises a tuning coil wound around a ferrite core, a variable capacitor connected in parallel with the tuning coil, and a field effect transistor. One end of the tuning coil is connected to the gate electrode directly or through an impedance means, while the other end of the tuning coil is grounded. The output signal of the antenna tuning circuit is taken out from a selected one of the source or drain electrode of the field effect transistor, whereby the signal to noise ratio may be remarkably improved.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: September 6, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Yoshimi Iso, Eijiro Oshitani, Shin-ichi Ohashi, Shigeki Inoue