P2H-5 Small 3x2.5mm² Sized Surface Acoustic Wave Duplexer for US-PCS with Excellent Temperature and Frequency Characteristics

Using flattened-SiO 2 /Cu-electrode/36~48deg LiTaO 3 structure, small size (5 x5mm 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 2 /Cu- electrode/126~128degYX-LiNbO 3 , which has larger cou pling factor than above-mentioned substrate, a smaller sized (3x2.5mm 2 ) SAW duplexer with a good TCF has been realized.