Title :
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
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;
Conference_Titel :
Electronic Manufacturing Technology Symposium, 1988, Design-to-Manufacturing Transfer Cycle. Fifth IEEE/CHMT International
Conference_Location :
Lake Buena Vista, FL, USA
DOI :
10.1109/EMTS.1988.16156
