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:
Jul. 28, 2020
Filed:
Dec. 20, 2018
Tdk Corporation, Tokyo, JP;
Yuta Ashida, Tokyo, JP;
Shigemitsu Tomaki, Tokyo, JP;
Yousuke Futamata, Tokyo, JP;
Shin Takane, Tokyo, JP;
Yasuharu Miyauchi, Tokyo, JP;
Kazunari Kimura, Tokyo, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
A dielectric filter includes a plurality of dielectric resonators. The dielectric filter also includes: a plurality of resonator body portions each formed of a first dielectric and respectively corresponding to the plurality of dielectric resonators, the first dielectric having a first relative permittivity; a peripheral dielectric portion formed of a second dielectric and lying around the plurality of resonator body portions, the second dielectric having a second relative permittivity lower than the first relative permittivity; and a shield portion formed of a conductor. Either one of a temperature coefficient of resonant frequency of the first dielectric at 25° C. to 85° C. and a temperature coefficient of resonant frequency of the second dielectric at 25° C. to 85° C. has a positive value and the other has a negative value.