TFBAR filters for 2 GHz wireless applications

Author

Kim, K.W. ; Yook, J.G. ; Gu, M.G. ; Song, W.Y. ; Yoon, Y.J. ; Park, H.K.

Author_Institution

Dept. of Electr. & Electr. Eng, Yonsei Univ., Seoul, South Korea

Volume

2

fYear

2002

fDate

2-7 June 2002

Firstpage

1181

Abstract

Thin film bulk acoustic resonators (TFBAR) using AlN with two electrodes have been used in the design of band pass filters at 2 GHz frequency bands. Both membrane and air-gap are used to suppress the over-mode phenomenon. Resonator modeling was performed based on measured frequency response of a single resonator with modified Butterworth-Van Dyke (MBVD) model. Electric coupling coefficient, k, is 0.2075 (4.3%) and Q is 577.18 for a single TFBAR. Additional TFBAR is used to improve out of band rejection In the conventional ladder topology and each contributes -3 dB suppression improvement at stop-band. Four different types of ladder filters were fabricated and modelled and revealed only -2 to -3 dB insertion loss for all the cases with bandwidth of around 52 MHz.

Keywords

Q-factor; UHF filters; acoustic resonator filters; band-pass filters; ladder filters; thin film devices; -2 to -3 dB; 2 GHz; 52 MHz; AlN; AlN electrode; Butterworth-Van Dyke model; Q-factor; TFBAR filter; air gap; band rejection; band-pass filter; electric coupling coefficient; frequency response; insertion loss; ladder filter; membrane; over-mode suppression; thin film bulk acoustic resonator; wireless communication; Acoustic measurements; Air gaps; Band pass filters; Biomembranes; Electrodes; Film bulk acoustic resonators; Frequency; Performance evaluation; Resonator filters; Transistors;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 2002 IEEE MTT-S International

Conference_Location

Seattle, WA, USA

ISSN

0149-645X

Print_ISBN

0-7803-7239-5

Type

conf

DOI

10.1109/MWSYM.2002.1011861

Filename

1011861