Synthesis of narrowband AlN Lamb wave ladder-type filters based on overhang adjustment

Author

Yen, Ting-Ta ; Lin, Chih-Ming ; Hopcroft, Matthew A. ; Kuypers, Jan H. ; Senesky, Debbie G. ; Pisano, Albert P.

Author_Institution

Berkeley Sensor & Actuator Center, Univ. of California at Berkeley, Berkeley, CA, USA

fYear

2010

fDate

11-14 Oct. 2010

Firstpage

970

Lastpage

973

Abstract

By adjusting the aluminum nitride (AlN) "overhang" dimension, OH, measured from the center of the outermost electrode to the edge of AlN plate, independently of the interdigital transducer (IDT) pitch, AlN Lamb wave mode resonators (LWRs) with 0.25% relative frequency control were demonstrated. Unlike adjusting electrode number, NE, device length, L, and electrode coverage, η, all of which affect device parameters such as Q, R_m, C₀, and k_t², overhang frequency selection technique can linearly shift the center frequency up to 2.5% with no influence on other resonator parameters. Preliminary results of narrowband ladder filters using these finely spaced AlN LWRs as building blocks were fabricated and measured. Fine tuning of bandwidth and center frequency were studied.

Keywords

aluminium compounds; interdigital transducers; ladder filters; surface acoustic waves; AlN; AlN Lamb wave mode resonators; aluminum nitride; interdigital transducer pitch; narrowband AlN Lamb wave ladder-type filters; overhang adjustment; overhang frequency selection technique; Electrodes; Filter banks; Frequency control; Narrowband; Resonant frequency; Resonator filters; Aluminum nitride (AlN); Lamb wave mode resonator (LWR); channel-select; filter bank; ladder-type filter; narrowband;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium (IUS), 2010 IEEE

Conference_Location

San Diego, CA

ISSN

1948-5719

Print_ISBN

978-1-4577-0382-9

Type

conf

DOI

10.1109/ULTSYM.2010.5935975

Filename

5935975