A variable surface acoustic wave delay line utilizing a voltage controlled air gap

Abstract

A surface acoustic wave (SAW) delay line is demonstrated which is variable and employs interaction between the SAW on a piezoelectric substrate and an adjacent electrically conductive film. With this structure, a tunability of 2.7×10−3 has been achieved by electrically controlling an air gap between a gold film and a (YZ)LiNbO3 substrate. Improvements in the air-gap fabrication techniques could increase the tunability up to ∼10−2.