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. 05, 2017
Filed:
Nov. 06, 2015
Murata Manufacturing Co., Ltd., Nagaokakyo-shi, Kyoto-fu, JP;
Michio Kadota, Nagaokakyo, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A tunable filter is a ladder circuit tunable filter including serial arm resonators and a parallel arm resonator. The serial arm resonators and the parallel arm resonator include elastic wave resonators. Variable capacitors are connected in series to the serial arm resonators, a variable capacitor is connected in parallel to the parallel arm resonator, and first inductors are connected in series to the serial arm resonators. When an impedance at a resonant frequency of the serial arm resonators is Zrs and an impedance at a resonant frequency of the parallel arm resonator is Zrp, a ratio Zrs/Zrp is not greater than 1.