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:
Aug. 11, 2015
Filed:
Jul. 21, 2011
Shigemitsu Tomaki, Tokyo, JP;
Yoshikazu Tsuya, Tokyo, JP;
Masamichi Tanaka, Tokyo, JP;
Isao Abe, Tokyo, JP;
Shigemitsu Tomaki, Tokyo, JP;
Yoshikazu Tsuya, Tokyo, JP;
Masamichi Tanaka, Tokyo, JP;
Isao Abe, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A bandpass filter module includes a mounting board and a BPF chip mounted on a surface thereof. The BPF chip includes three or more resonators; a first-stage resonator located closest to an input terminal, a final-stage resonator located closest to an output terminal, and a middle-stage resonator connected between the first-stage and the final-stage resonators and located in a chip middle zone. The mounting board includes an area overlapping with the chip middle zone, viewed in plan, defining a ground-free space in which no ground electrode is disposed. The ground-free space is formed at least from the surface of the mounting board to a depth position at which a topmost internal wiring layer is located. The middle-stage resonator is prevented from being coupled to ground electrodes on the mounting board and from a lower Q-value and increased insertion loss.