Lossy surface acoustic wave (SAW) device with piezoelectric substrate, for GHz band - constitutes resonator, filter or delay line on substrate cut at optimal angle with respect to thickness of interdigital electrodes.

摘要

The device is formed on a theta-rotated Y-X-cut lithium tantalate or lithium niobate single crystal (11) carrying interdigital electrode patterns (R1,R1',R2,R2',R2") with a thickness amounting to 0.4 mu m or about 10% of the SAW passband wavelength. The form factor is influenced by the angle of cut which is chosen between 38 deg and 46 deg so that the minimum insertion loss is reduced to less than 1.6 dB. The electrodes are of aluminium alloy containing 1 wt.% of copper.