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We present high-performance shear horizontal surface acoustic wave (SH-SAW) and longitudinal leaky SAW (LL-SAW) devices using lithium tantalate (LiTaO3) thin films on silicon carbide (SiC) substrate. The 4-in LiTaO3-on-SiC (LTOSiC) hetero-substrate was prepared by an ion-slicing process. Instead of the Si-based piezo-on-insulator substrates, generally embedded with functional dielectric layers (e. g. , SiO2), LTOSiC with a simple structure has achieved exciting results on device frequency, quality factor (Q), temperature coefficient of frequency (TCF), and thermal transport properties. The demonstrated resonators show the scalable resonances of 1. 19–4. 91 GHz, in which the gigahertz SH-SAW resonator exhibits an ultrahigh Bode- Q of 8100 and an excellent TCF of −4. 3 ppm/K, while the LL-SAW resonator presents a high Bode- Q of 1000 and an improved TCF of −25. 4 ppm/K at 5. 0 GHz. Besides, the demonstrated filters show the center frequencies (f₂) of 2. 74–4. 26 GHz, the insertion loss (IL) below 1. 26 dB, and an out-of-band (OoB) rejection of 10–45 dB. The SH-SAW-based filter shows a f₂ of 3. 36 GHz, an IL of 0. 78 dB, and a 3-dB bandwidth of 180 MHz, while the LL-SAW-based filter shows a f₂ of 3. 85 GHz and an IL of 0. 85 dB. Overall, LTOSiC may serve as an advanced material platform of acoustic devices for 5G-frequency range 1 (5G-FR1) bands.
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