Resonator filters using shear horizontal-type leaky surface acoustic wave consisting of heavy-metal electrode and quartz substrate |
| |
Authors: | Kadota Michio Yoneda Toshimaro Fujimoto Koji Nakao Takeshi Takata Eiichi |
| |
Affiliation: | Murata Mfg. Co. Ltd., Kyoto, Japan; |
| |
Abstract: | The authors have succeeded in exciting a new type of leaky surface acoustic wave (LSAW) having only a shear horizontal (SH) component that has a large electromechanical coupling factor, a large reflection coefficient, and excellent temperature stability, by combining interdigital transducers (IDTs) and reflectors made of heavy-metal films such as gold (Au), tantalum (Ta), and tungsten (W) on the ST-cut 90/spl deg/ X propagation (direction perpendicular to the X-axis) quartz substrate. This LSAW does not have a propagation decay. The square of the electromechanical coupling factor is 2.1-2.7 times larger than, the reflection coefficient is 30 times larger than, and the temperature characteristic is the same as those of a Rayleigh wave on an ST-cut X propagation quartz substrate. The authors applied this SH LSAW to resonators and resonator filters. As a result, we succeeded in developing the low loss and very small-sized resonators and resonator filters (1/5-1/4 of conventional device sizes) with IDTs with a small number of finger pairs and very small reflectors, for the first time. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|