The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 14, 1997
Filed:
Sep. 11, 1995
Koichi Sakai, Tsurugashima, JP;
Ken Kasahara, Tsurugashima, JP;
Hajime Yokoyama, Tsurugashima, JP;
Noboru Takada, Tsurugashima, JP;
Yukio Suzuki, Tsurugashima, JP;
Toko Kabushiki Kaisha, Tokyo-to, JP;
Abstract
An electronic tuning circuit for an AM radio receiver in which a signal of a specific frequency is selected from the input signal from an antenna is provided, this tuning circuit having a tuning transformer with a first winding and a second winding, the number of turns on the first winding being greater than the number of turns on said second winding, the input from the antenna being applied to the second winding of the tuning transformer, and further having two varactor diodes, each of which is connected in series with a DC-blocking capacitor, these series-connected varactor-capacitor combinations being connected in parallel with the first winding of the tuning transformer such that the polarities of the varactor diodes are mutually opposing.