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:
Jun. 08, 2021
Filed:
Oct. 02, 2019
Acoustic wave filter device, duplexer, radio frequency front end circuit and communication apparatus
Murata Manufacturing Co., Ltd., Kyoto, JP;
Koji Nosaka, Kyoto, JP;
MURATA MANUFACTURING CO., LTD., Kyoto, JP;
Abstract
The acoustic wave filter (A) includes a parallel-arm resonant circuit (). The parallel-arm resonant circuit () includes a parallel-arm resonator (p) and a frequency variable circuit () that are connected in parallel. The frequency variable circuit () includes a parallel-arm resonator (p) that has a resonant frequency higher than that of the parallel-arm resonator (p) and a switch (SW) element. A frequency difference between a resonant frequency on a higher frequency side of the parallel-arm resonant circuit () in a case where the switch (SW) is OFF and a resonant frequency on a higher frequency side of the parallel-arm resonant circuit () in a case where the switch (SW) is ON is equal to or more than a frequency difference between a low frequency end frequency of the second attenuation band and a low frequency end frequency of the first attenuation band.