Acoustic Losses in Busbars

Radiation of acoustic waves from the contact elec- trodes (busbars) of surface acoustic wave (SAW) devices on high-coupling piezoelectric substrates, such as 42 ◦ -LiTaO3 ,i s demonstrated both with Finite-Element-Method (FEM) simula- tions 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.