Title:
IMPROVEMENT OF FREQUENCY TEMPERATURE COEFFICIENT IN FILTER TRANSITION BAND WHILE MAINTAINING PASS BANDWIDTH
Document Type and Number:
Japanese Patent JP2019195166
Kind Code:
A
Abstract:
To improve a TCF in a filter transition band without sacrificing pass bandwidth in a remote communication system that has a narrow band gap between a transmission band and a reception band, and a wide pass band.SOLUTION: An electronic filter includes: a plurality of serial arm acoustic wave resonators R1, R3A, R5, R7, and R9 that are disposed on a piezoelectric substrate 105 and electrically connected in series between an input port and an output port; a plurality of parallel arm acoustic wave resonators R2, R4, R6, and R8 that are electrically connected in parallel, whose first side is electrically connected between each of the serial arm acoustic wave resonators, and whose second side is electrically connected with a ground; and at least one additional acoustic wave resonator R3B that is electrically connected in parallel to one of one of the plurality of serial arm acoustic wave resonators and one of the plurality of parallel arm acoustic wave resonators and whose frequency temperature coefficient (TCF) is lower than the TCF of the electrically parallel connected acoustic wave resonator.SELECTED DRAWING: Figure 1A
Inventors:
KOMATSU TOMOYA
FUJIWARA SHIROJI
FUJIWARA SHIROJI
Application Number:
JP2019082847A
Publication Date:
November 07, 2019
Filing Date:
April 24, 2019
Export Citation:
Assignee:
SKYWORKS SOLUTIONS INC
International Classes:
H03H9/64; H03H3/02; H03H3/08; H03H9/145; H03H9/17; H03H9/54; H03H9/70; H03H9/72
Attorney, Agent or Firm:
Hidekazu Miyoshi
Masakazu Ito
Yuko Hara
Masakazu Ito
Yuko Hara