Title :
SAW substrate for Duplexer with Excellent Temperature Characteristics and Large Reflection Coefficient realized by using Flattened SiO2 Film and Thick Heavy Metal Film
Author :
Kadota, Michio ; Nakao, Takeshi ; Taniguchi, Norio ; Takata, Eiichi ; Mimura, Masakazu ; Nishiyama, Kenji ; Hada, Takuo ; Komura, Tomohisa
Author_Institution :
Murata MFG Co.Ltd., Nagaokakyo
Abstract :
Authors previously proposed a SAW PCS-duplexer with an excellent temperature coefficient of frequency (TCF) and a good frequency characteristic composed of a thick-SiO2/thin-Au-electrodes/LiTaO3 structure. However, a sheet resistance of thin Au electrode is large, compared with thick Al-electrode, so thin Au-electrode is not suitable for filters requiring low loss. Authors tried to use thick Cu electrodes with small resistance. By flattening large convex portions on the SiO2 surface, a SAW substrate suitable for US-PCS duplexer with low insertion loss and an excellent TCF was realized
Keywords :
electrodes; gold; lithium compounds; multiplexing equipment; silicon compounds; surface acoustic wave filters; tantalum compounds; thin films; SAW PCS-duplexer; SAW substrate; SiO2-Au-LiTaO3; US-PCS duplexer; flattened SiO2 film; heavy metal film; insertion loss; reflection coefficient; sheet resistance; thick Al-electrode; thick Cu electrodes; thin Au electrode; Electrodes; Filters; Frequency; Gold; Optical films; Reflection; Substrates; Surface acoustic waves; Surface resistance; Temperature; Cu electrode; Excellent TCF; LiTaO3; duplexer; flattened SiO2;
Conference_Titel :
Microwave Symposium Digest, 2006. IEEE MTT-S International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-9541-7
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2006.249550
