Title:
SURFACE ACOUSTIC WAVE DEVICE
Document Type and Number:
Japanese Patent JP3175581
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To suppress the deterioration of insertion loss via a simple circuit constitution by inserting a single terminal paired SAW(surface acoustic wave) resonator and a capacitor in series between the connection point of two parallel SAW filters and a 1st SAW filter.
SOLUTION: A capacitor 25 and a single terminal paired SAW resonator 26 are connected between a 1st SAW filter 22 and a connection point 24. The capacitor 25 has its impedance larger than 1/4 terminal impedance of an SAW device 21, and the resonator 26 has its anti-resonance frequency that is higher than the pass band of the filter 22. In such a constitution, it is possible to suppress the increase of insertion loss of the filter 22 and also the deterioration of VSWR in a pass band when the impedance must be increased in the pass band of a 2nd SAW filter 23.
Inventors:
Katsuhiro Raft
Eiji Ieki
Eiji Ieki
Application Number:
JP5803696A
Publication Date:
June 11, 2001
Filing Date:
March 14, 1996
Export Citation:
Assignee:
MURATA MANUFACTURING CO.,LTD.
International Classes:
H03H9/145; H03H9/25; H03H9/72; (IPC1-7): H03H9/72
Domestic Patent References:
| JP4253414A | ||||
| JP5167388A | ||||
| JP9284093A |
Attorney, Agent or Firm:
Miya Saki Main tax (1 person outside)