Small 3×2.5mm{sup}2 sized Surface Acoustic Wave Duplexer for US-PCS with Excellent Temperature and Frequency Characteristics

摘要

Using flattened-SiO{sub}2/Cu-electrode/36～48° LiTaO{sub}3 structure, small size (5×5mm{sup}2) surface acoustic wave (SAW) duplexer with a good temperature coefficient of frequency (TCF) for US-PCS was realized by authors. However, a smaller duplexer has been strongly required. Using flip-chip bonding process of SAW chips and Rayleigh SAW propagating on the flattened-SiO{sub}2/Cu-electrode/126～128°YX-LiNbO{sub}3, which has larger coupling factor than above-mentioned substrate, a smaller sized (3×2.5mm{sup}2) SAW duplexer with a good TCF has been realized.