Acoustic Attenuation of a Single-Domain Lithium Niobate Crystal at Microwave Frequencies

The pulse echo technique is employed to measure the acoustic wave attenuation along the c axis of a single-domain lithium niobate crystal at room temperature up to c band frequencies. Initial experiments show that the frequency dependence of the attenuation is nearly quadratic as predicted by theory. Approximately 13 dB of loss per μsec of time delay is observed at 5.5 GHz. The relatively low-loss characteristics, coupled with the self-transduction properties, make lithium niobate a leading candidate for microwave room-temperature delay line applications.