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:
Sep. 29, 1992
Filed:
Nov. 15, 1990
Kazuhiko Nakase, Tokyo, JP;
Moriyoshi Kawasaki, Kanagawa, JP;
Harada Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An automobile mast antenna used in a state shorter than its resonant state including an FM compensating circuit made only of passive elements and compensating for FM signals and an AM compensating circuit made of active elements that convert high impedance into low impedance and compensating for AM signals. The FM compensating circuit is formed with a primary resonance circuit and a secondary resonance circuit, in which the primary resonance circuit resonates in FM band via impedance of an antenna mast and loading coil which is attached to the antenna mast, and the secondary resonance circuit resonates in FM band via a coil and capacitor. The primary and secondary resonance circuits are coupled by electrostatic capacitance of attachment section of the antenna mast so as to form a double-tuned circuit.