Generation, propagation, and attenuation of 10 GHz-range SAW in LiNbO3

10 GHz-range SAW properties are very important in the field of the physical acoustics and the application of SAW devices. The temperature dependence of the propagation attenuation in the 10 GHz-range is measured using the 3-interdigital transducers (IDT) system with electrode width of below 0.1 μm. The results show that the attenuation at room temperature is about 1.5 dB/100 λ at 10 GHz. Nanometer fabrication processing for GHz SAW devices with various types of fine lithography technology for electrode fabrication and low-loss filters using unidirectional transducers are described. The lift-off lithography techniques for 10 GHz SAW IDT on 128° Y-X LiNbO₃ using direct electron beam writing are shown. Most of the insertion loss of the filter is caused by the resistivity of IDT due to the very thin and narrow metal electrodes. The insertion loss of the temperature dependence using Al-IDT and superconducting Nb-IDT is investigated experimentally. The results for Nb-IDT electrode showed a dramatic decreasing insertion loss change around the superconducting temperature. We have also found an insertion loss of about 8 dB at 8 GHz at low temperature