Super high frequency lithium niobate surface acoustic wave transducers up to 14 GHz

We report lithium niobate (LiNbO
₃
) surface acoustic wave (SAW) transducers with the smallest linewidth and the highest resonant frequency. A record 30 nm wide, 200 nm period (λ
₀
) nanofabricated metallic structure on non-conductive LiNbO
₃
enables a frequency exceeding 14 GHz. At higher frequencies, greater data throughputs and improved sensor sensitivity are enabled. A systematic study of SAW devices from λ
₀
=200-800 nm is presented taking into account crystal orientation, device design, patterning strategies, and resonant modes. The device performance metrics such as frequency, g-factor, insertion loss, and coupling coefficient are measured in detail and these metrics are also found to exceed the results of other recent state-of-the-art devices, when compared.