Abstract
The transition bandwidth of 20 MHz between the transmission (Tx: 1850–1910 MHz) and the receiving (Rx: 1930–1990 MHz) bands of personal communication service (PCS) handy phones in the United States (US) is very narrow compared with those of other systems. We have already realized surface acoustic wave (SAW) duplexers with sizes of 5.0×5.0×1.7 and 3.0×2.5×1.2 mm3 for PCS handy phones in the US with an excellent temperature coefficient of frequency (TCF) by using a shear horizontal (SH) wave on a flattened SiO2/Cu electrode/36–48° YX-LiTaO3 structure and a Rayleigh wave on a SiO2/Cu electrode/120–128° YX-LiNbO3 structure. Although the surface of the above-mentioned structures is flattened SiO2, we have also studied the shape of the SiO2 surface. As a result, in addition to increasing the stop-band width, which corresponds to the reflection coefficient, the TCF and power durability have been improved by forming convex portions on the surface of the SiO2 over the interdigital transducer (IDT) gaps.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
