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. 12, 1999
Filed:
May. 24, 1996
Yoshiaki Terashima, Yokosuka, JP;
Hisashi Yoshino, Tokyo, JP;
Hiroyuki Kayano, Kawasaki, JP;
Tadahiko Maeda, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A first electrically conductive layer whose thickness is equal to or smaller than the skin depth of the radio wave used for communication, a dielectric layer whose permittivity is changed by application of electric field, and a second electrically conductive layer whose thickness is equal to or smaller than the skin depth of the radio wave used for communication are sequentially stacked near a resonance element which is formed on the front surface of a dielectric substrate having a ground layer formed on the rear surface thereof. The effective permittivity of the dielectric layer is changed in a wide range by changing a voltage applied between the first and second electrically conductive layers to change the electric field applied to the dielectric layer. As a result, the impedance of the resonance element is changed, and when a plurality of resonance elements are arranged closely to each other to construct a filter, the coupling degree between the resonance elements is changed. Therefore, characteristics such as the resonance frequency of the resonator and the pass-band frequency of the filter are controlled by controlling a voltage to be applied.