An analysis and improvement of balanced-type SAW filters

Author

Nakamura, Hiroyuki ; Tsuzuki, Shigeru ; Yamada, Toru ; Ishizaki, Toshio

Author_Institution

Matsushita Electr. Ind. Co. Ltd., Osaka, Japan

Volume

1

fYear

2002

fDate

8-11 Oct. 2002

Firstpage

163

Abstract

The degradation mechanism of balance performance for balanced-type SAW filters was analyzed. The authors have confirmed that the parasitic coupling between input and output IDTs makes the balance characteristics degrade. The measurement results show good agreement with simulations by assuming the parasitic capacitances. The balance characteristics can be improved by decreasing the parasitic capacitances. Further, the much better performance can be obtained by connecting inductors between input and output IDTs. Parallel resonance circuit with additional inductor and the parasitic capacitance can solve the problem successfully. The experimental balanced-type SAW filter shows an excellent performance. These values satisfy the system requirements.

Keywords

interdigital transducers; surface acoustic wave filters; IDT; balance performance degradation mechanism; balanced-type SAW filters; parallel resonance circuit; parasitic capacitance; parasitic coupling; Capacitance measurement; Circuit simulation; Degradation; Inductors; Joining processes; Parasitic capacitance; Performance analysis; RLC circuits; Resonance; SAW filters;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE

ISSN

1051-0117

Print_ISBN

0-7803-7582-3

Type

conf

DOI

10.1109/ULTSYM.2002.1193376

Filename

1193376