Title :
IIDT type low-loss SAW filters with improved stopband rejection in the range of 1 to 2 GHz
Author :
Yatsuda, Hiromi ; Inaoka, T. ; Takeuchi, Y. ; Horishima, T.
Author_Institution :
Japan Radio Co. Ltd., Saitama, Japan
Abstract :
Interdigitated interdigital transducer (IIDT)-type surface acoustic wave (SAW) filters with suppressed sidelobes and reduced insertion losses are described. The filters are composed of multiple withdrawal-weighted IDTs in different withdrawal positions. An 878-MHz filter composed of 13 IDTs was designed by this method. This filter has a minimum insertion loss of 1.6 dB and a stopband rejection of about 30 dB. Three filters with center frequencies of 0.9 GHz, 1.5 GHz, and 1.9 GHz were fabricated using the lift-off process. Their frequency responses are almost the same, and the insertion losses are less than 3 dB
Keywords :
acoustic microwave devices; frequency response; microwave filters; radiofrequency filters; surface acoustic wave filters; ultrasonic transducers; 0.9 to 1.9 GHz; 1.6 dB; 2 dB; 878 MHz; AlCu-Ti-LiTaO3; IIDT; LiTaO3; frequency responses; lift-off process; low-loss SAW filters; minimum insertion loss; multiple withdrawal-weighted IDTs; stopband rejection; suppressed sidelobes; Degradation; Design methodology; Electrodes; Frequency response; Insertion loss; Passband; Resonator filters; SAW filters; Telephony; Transducers;
Conference_Titel :
Ultrasonics Symposium, 1992. Proceedings., IEEE 1992
Conference_Location :
Tucson, AZ
Print_ISBN :
0-7803-0562-0
DOI :
10.1109/ULTSYM.1992.276062
