Title :
High performance balanced type SAW filters in the range of 900 MHz and 1.9 GHz
Author :
Endoh, G. ; Ueda, M. ; Kawachi, O. ; Fujiwara, Y.
Author_Institution :
Fujitsu Labs. Ltd., Kawasaki, Japan
Abstract :
This paper describes balanced SAW filters with low insertion loss and high stopband rejection, which are applicable to 900 MHz and 1.9 GHz range portable telephone. The longitudinal coupled type double mode SAW design is suitable for balanced filter design. The 42 degree Y-X LiTaO 3 substrate is chosen to get low insertion loss and high Q factor performances. The design and evaluation method are studied and the effect of phase difference between balanced terminal signals is shown. The new filter design makes it possible to convert input/output impedance in order to match to an IC impedance
Keywords :
Q-factor; UHF filters; cellular radio; lithium compounds; losses; surface acoustic wave filters; 900 MHz to 1.9 GHz; IC impedance; LiTaO3; LiTaO3 substrate; balanced SAW filters; balanced filter design; balanced terminal signals; filter design; high Q factor; high performance balanced type SAW filters; high stopband rejection; input/output impedance; longitudinal coupled type double mode SAW design; low insertion loss; phase difference; portable telephone; Circuits; GSM; Impedance; Insertion loss; Personal communication networks; Q factor; SAW filters; Signal design; Surface acoustic waves; Ultrasonic variables measurement;
Conference_Titel :
Ultrasonics Symposium, 1997. Proceedings., 1997 IEEE
Conference_Location :
Toronto, Ont.
Print_ISBN :
0-7803-4153-8
DOI :
10.1109/ULTSYM.1997.662976
