Design and fabrication process of 800 MHz band low loss SAW filter

Author

Sakamoto, Nobuyoshi ; Huor, Ou Hok ; Kasagi, Masakatsu ; Shibata, Susumu ; Nihei, Koji

Author_Institution

OKI Electr. Ind. Co. Ltd., Tokyo, Japan

fYear

1988

Firstpage

93

Lastpage

97

Abstract

The design technique, fabrication, and breakdown-test results are described of a low-loss SAW (surface acoustic wave) filter for use in mobile telephone equipment. A multitransducer structure was adopted to get a low-loss SAW filter composed of 13 transducers (seven unapodized and six withdrawal) formed on a 36 degrees YX-LiTaO/sub 3/ substrate. As a result, the pass band loss was from 1.8 dB to 2.2 dB. Because the filter was for use in the UHF band (800 MHz band), the fingers of each transducer were required to be of a hyperfine line width. To form such a transducer on the substrate, it is useful to use lift-off technology using deep-UV exposure.<>

Keywords

passive filters; radiofrequency filters; surface acoustic wave devices; ultrasonic transducers; 1.8 to 2.2 dB; 800 MHz; LiTaO/sub 3/; UHF band; breakdown-test results; deep-UV exposure; hyperfine line width; lift-off technology; low loss SAW filter; mobile telephone equipment; multitransducer structure; pass band loss; unapodized; withdrawal; Diffraction; Electric breakdown; Fabrication; Fingers; Frequency; Mass production; Process design; SAW filters; Surface acoustic waves; Transducers;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Manufacturing Technology Symposium, 1988, Design-to-Manufacturing Transfer Cycle. Fifth IEEE/CHMT International

Conference_Location

Lake Buena Vista, FL, USA

Type

conf

DOI

10.1109/EMTS.1988.16156

Filename

16156