P2M-2 Acoustic Losses in Busbars

Radiation of acoustic waves from the contact electrodes (busbars) of surface acoustic wave (SAW) devices on high-coupling piezoelectric substrates, such as 42deg-LiTaO₃, is demonstrated both with finite-element-method (FEM) simulations and with experimental data. This acoustic radiation, as well as resistive losses, significantly decrease the Q-value of the busbars. Experimental measurements on test structures show Q-values as low as about 10