Title :
Theoretical and experimental study of surface acoustic wave substrates with super high couplings
Author :
Yamanouchi, Kazuhiko ; Odagawa, Hiroyuki
Author_Institution :
Tohoku Inst. of Technol., Sendai, Japan
Abstract :
The properties of SAW device mainly depend on the choice of piezoelectric substrate materials. The important properties required for SAW substrates are large electromechanical coupling coefficient (k2 ), small temperature coefficient of delay (TCD), low propagation loss, etc. Especially, super high coupling substrates are very important for fabricating the wideband SAW filters, wideband VCO and delay lines with small insertion loss. KNbO3 single crystal has extremely large electromechanical coupling coefficient (K2=53%) and zero TCD around room temperature and single crystal growth technologies with a large size are now investigating. In this paper, the propagation characteristics of surface acoustic waves (SAW) in PZNT and KTP substrates are investigated experimentally in order to obtain the higher coupling substrates than those of the KNbO3. The experimental results show that the substrates have the large k2. Also, theoretical SAW propagation characteristics with the k2 of about 100% will be analyzed and the physical phenomena of those will be discussed
Keywords :
lead compounds; piezoelectric materials; potassium compounds; surface acoustic waves; titanium compounds; KTP; KTiOPO4; PZNT; Pb(ZnNb)O3-PbTiO3; electromechanical coupling coefficient; piezoelectric substrate; propagation loss; surface acoustic wave propagation; temperature coefficient of delay; Acoustic propagation; Acoustic waves; Piezoelectric materials; Propagation delay; Propagation losses; SAW filters; Surface acoustic wave devices; Surface acoustic waves; Temperature; Wideband;
Conference_Titel :
Ultrasonics Symposium, 2000 IEEE
Conference_Location :
San Juan
Print_ISBN :
0-7803-6365-5
DOI :
10.1109/ULTSYM.2000.922567
