Thin Film bulk acoustic wave devices have the advantages of low loss, low temperature coefficient of the resonant frequency, and high power handling. These excellent characteristics are suitable for the applications on high frequency communication systems.
In this study, thin film bulk acoustic wave filters using the ladder-type filter and stacked crystal filter configurations were investigated. Platinum was chosen as the top and bottom electrodes. To improve the platinum adhesion on SiNx/SiO2/Si substrates, a seeding layer of titanium is used. Highly c-axis oriented piezoelectric zinc oxide thin films were deposited by two-step deposition method under room temperature.
As resonant area decreases, the band rejection of ladder-type filter will increase. Because the resonant area decreased, the distance between signal and ground will increase the results in an increased insertion loss. On the other hand, stacked crystal filters have larger band rejection and less 3dB bandwidth, which are suitable for the application of narrow band filters.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0815108-154514 |
| Date | 15 August 2008 |
| Creators | Tsai, Tzung-ru |
| Contributors | S. J. Chang, J.L. Huang, Mau-Phon Houng, R. S. Guo, Ying-Chung Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0815108-154514 |
| Rights | not_available, Copyright information available at source archive |
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