Highly Tunable Piezoelectric Resonators Using Al0.7Sc0.3N

We report a frequency tunable Lamb wave piezoelectric resonator using an Al0.7Sc0.3 N thin film. The frequency tuning of the resonator is demonstrated by its stiffness manipulation which is achieved by terminating the tuning electrodes (TE) with a variable capacitor. Resonators with 2, 3, 4, and 5 TE were fabricated and characterized. The highest tuning range of 24,694 ppm was achieved for the resonator with 5 TE. Whereas the best insertion loss of approximately −6 dB was demonstrated by the resonator with 2 TE. The tunning range (17,783
$\sim $
24,694 ppm) achieved by the Al0.7Sc0.3 N resonators is higher than zero power demonstrations in prior studies. The resonators are fabricated using a commercial XBAW
$^{\mathrm {TM}}$
process making it suitable for mass production without any needed exotic processing steps or materials. The resonators are promising for miniaturization of modern wireless communications system by providing a platform to process multi-channel frequencies with reduced components. [2023-0193]