Radio frequency (RF) filters in high frequency surface acoustic wave (SAW) such as MediaFLOTM, Division Synchronous Code Division Multiple Access (TDSCDMA) China handy phone system, and global positioning (GPS) in cars require a narrow bandwidth. So, the substrates for their RF filters are also required to have very excellent temperature coefficient of frequency (TCF) and electro-mechanical coupling factor. Rayleigh wave on ZnO film/Al-electrode/ quartz structures and shear horizontal (SH) type of leaky SAW (LSAW) on a flattened SiO2/high metal electrodes/36°-48°YX-LiTaOSiO 3 one have good TCF suitable coupling factor to realize them. On the other , large reflection coefficient is required to realize the multimode filter. Though the latter has the large reflection , the farmer has small one. So, in the case of the former , authors also attempted to apply a high density metal such as Au electrode instead of Al electrode to realize large reflection coefficient. As the result, the multi-mode filters composed of a ZnO/high density electrode/quartz a flattened SiO2/high density electrode/LiTaO3 with good for the RF range have been realized for the first time.
|ジャーナル||Proceedings - IEEE Ultrasonics Symposium|
|出版ステータス||Published - 2008 12 1|
|イベント||2008 IEEE International Ultrasonics Symposium, IUS 2008 - Beijing, China|
継続期間: 2008 11 2 → 2008 11 5
ASJC Scopus subject areas