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:
May. 21, 1985
Filed:
Feb. 12, 1982
Kazutaka Hidaka, Yokohama, JP;
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Abstract
The invention is directed to a tunable loop antenna design which provides impedance matching between the loop antenna and a feed line despite variations of the resonant frequency f.sub.o over a wide range of frequencies. The antenna has a maximum length of one tenth of the wavelength, and comprises a loop conductor and a variable capacitor connected in series with the conductor for providing a resonant circuit. The loop area of the conductor, the circumferential length and equivalent radius thereof are adjusted so that the ratio of the resonant frequency f.sub.o of the antenna and the resonant frequency f.sub.m, at which the input admittance is a minimum, is within the range: