Design of low loss surface acoustic wave filter with three interdigital transducers

Author

Jiang, Xin ; Shi, Yu ; Wang, Hua-lei ; Zhao, Bao-lin ; Du, Bo

Author_Institution

State Key Lab. of Electron. Thin Films & Integrated Devices, Univ. of Electron. Sci. & Technol. of China, Chengdu

fYear

2008

fDate

5-8 Dec. 2008

Firstpage

300

Lastpage

303

Abstract

A structure of low loss surface acoustic wave filter with Single-Phase Unidirectional Transducers (SPUDTS) is described in this paper. In this structure, two single-phase unidirectional transducers are placed at both sides of one apodized transducer. The loss has caused by bidirectional acoustic wave can be canceled by unidirectional characteristic of SPUDTS. Moreover the frequency response of the filter can be designed by changing weighting function of the apodized transducer. The simulation of this filter is based on Coupled-of-Mode, which can exactly calculate inner reflection of transducers. The transducers should be divided into so-called building blocks, and then calculate their P-matrixes, finally the response can be achieved by cascading P-matrixes. The center frequency of 110 MHz SAW filter is fabricated on YX-128deg LiNbO₃. Its 3 dB bandwidth is 1.7 MHz, and insertion loss is -5.6 dB.

Keywords

coupled mode analysis; frequency response; interdigital transducers; surface acoustic wave filters; surface acoustic wave transducers; SAW filter; apodized transducer; bandwidth 1.7 MHz; bidirectional acoustic wave; coupled-of-mode simulation; frequency 110 MHz; frequency response; interdigital transducers; loss -5.6 dB; low loss surface acoustic wave filter; single-phase unidirectional transducers; weighting function; Acoustic reflection; Acoustic transducers; Acoustic waves; Electronic mail; Frequency response; Laboratories; SAW filters; Surface acoustic wave devices; Surface acoustic waves; Thin film devices; SAW Filter; coupled-of-mode; low loss; single-phase unidirectional transducers;

fLanguage

English

Publisher

ieee

Conference_Titel

Piezoelectricity, Acoustic Waves, and Device Applications, 2008. SPAWDA 2008. Symposium on

Conference_Location

Nanjing

Print_ISBN

978-1-4244-2891-5

Type

conf

DOI

10.1109/SPAWDA.2008.4775796

Filename

4775796