Portal de Periódicos da CAPES

Super Low Velocity/Piezoelectric Substrate Structure with High Reflections and Applications for Surface Acoustic Wave Wide Band Resonators and Low-Loss Unidirectional Transducer Filters

2007; Institute of Physics; Volume: 46; Issue: 7S Linguagem: Inglês

10.1143/jjap.46.4739

1347-4065

Yusuke Satoh, Kazuhiko Yamanouchi,

Mechanical and Optical Resonators

In this paper, the propagation characteristics and reflectivities of TeO2 grating/128° Y–X LiNbO3, 36° Y–X LiTaO3, and 5° Y–X LiNbO3 are analyzed and applied to resonators and, conventional and dispersive unidirectional transducers. Theoretical results of thin film gratings show the large impedance ratio, for example, thin film grating shows r=0.96 at a thickness of H/λ=0.01, for 128° Y–X LiNbO3. The experimental results for an interdigital transducer (IDT) resonator of thin film/Al/128° Y–X LiNbO3 with N=100,W=20λ,H/λ=0.01 show an admittance of 1.0 S. The experimental unidirectional transducer filter using thin film TeO2 (H/λ=0.015)/Al/128° Y–X LiNbO3 show a 1.6 dB insertion loss at 500 MHz without matching. Moreover filters with the phase linear, flat wide band, and low loss characteristics are developed using dispersive unidirectional IDT.