Study of Electrode Configuration for Downsizing of SAW Resonators on Low-Cut Lithium Niobate

This paper discusses the electrode configuration preferable for downsizing of SAW resonators. Here, use of heavy metal electrodes on low-cut LiNbO
3
(LN) substrate is considered. First, variation of the SH-SAW velocity
$V_{p}$
and electromechanical coupling factor
$k^{2}$
is investigated with the electrode material choice. It is shown that heavy and stiff materials such as W is preferable for the purpose. Then, choice of the LN cut angle is also discussed for the Rayleigh-SAW suppression. Furthermore, use of double-layered electrode structure is discussed for reduction of electrode resistance. It is shown that use of soft, light and highly conductive material such as Al is preferable as the top layer in combination with the W bottom layer for minimizing
$k^{2}$
deterioration.