Surface Wave and Lamb Wave Acoustic Devices on Heterogenous Substrate for 5G Front-Ends

Abstract

We demonstrate groups of surface wave (SH0 mode) and Lamb wave (S0 mode) acoustic devices on lithium niobate thin films on silicon carbide (LNOSiC) heterogeneous substrate. The 4-inch LNOSiC with an excellent thermal transport property is prepared by ion-cutting process. The fabricated acoustic resonators on the LNOSiC substrate show scalable resonances from 2.0 to 4.72 GHz, in which the SH0 (S0) mode resonator shows a $k_t^2$ of 24.1% (15.5%) and a maximum Bode-Q of 976 (577) at 2.54 (3.56) GHz. Moreover, the phase velocity (Vp) of the SH0 (S0) mode is greater than 5000 (6400) m/s, which is about 1.25 (1.6) times higher than that of the conventional SAWs, so as the operating frequency. The filter with a center frequency of 2.62 GHz, an insertion loss (IL) of 1.06 dB, and a 3-dB fractional bandwidth (FBW) of 12.6% (three times larger than that of the conventional SAWs) is also achieved. The acoustic devices on heterogeneous substrate are very promising for high frequency, wideband and high power 5G front-ends.