X-Cut Lithium Niobate-Based Shear Horizontal Resonators for Radio Frequency Applications

RF acoustic microsystems based on suspended lithium niobate thin films: advances and outlook

“…A well-established approach for quantifying acoustic damping is to compare resonators with the highest Q. The survey of the reported high k 2 resonators in thinfilm LiNbO 3 is shown in figure 9 [118], including SH0 [17,22,23,[27][28][29][30][31][32], S0 [13][14][15][16][17][18], and A1 mode devices [35, 36, 39-41, 48, 69, 119, 120], sorted by operating frequencies and film thickness. It is clear from figure 9(a) that devices at higher frequencies show higher damping, consistent with that measured in bulk LiNbO 3 [117].…”

“…This can be intuitively explained as the thin-film better confines both the acoustic and electric fields within a smaller volume, leading to stronger interaction through piezoelectricity. The commonly used modes include fundamental symmetric (S0) [13][14][15][16][17][18][19][20][21], fundamental shear horizontal (SH0) [22][23][24][25][26][27][28][29][30][31][32][33][34], 1st-order antisymmetric (A1) [35][36][37][38][39][40][41][42][43][44][45][46], thickness-shear (TS) [47-50], thicknessextensional (TE) [51][52][53][54][55], and higher-order Lamb modes [53,[56][57][58][59]. Studies on thin-film LiNbO 3 growth date back to the sputtering deposition in the 1960s [60].…”

Topology optimization of MEMS resonators with target eigenfrequencies and modes

“…They are key components that are extensively employed in many of the aforementioned applications, such as frequency selection (e.g. MEMS radio-frequency (RF) and intermediate-frequency (IF) filters [1,2,3]), timing (i.e. MEMS oscillators [4,5,6]), inertial detection (i.e.…”

Acoustic Loss of GHz Higher-Order Lamb Waves in Thin-Film Lithium Niobate: A Comparative Study

“…One promising frequency scaling scheme is using higher-order modes in piezoelectric thin films, e.g., lithium niobate (LiNbO 3 ) [10]- [15] and aluminum/scandium aluminum nitride (AlN/ScAlN) [16]- [23]. Different from fundamental modes, e.g., fundamental symmetric (S0) [24]- [27] and shear horizontal (SH0) [28]- [31] modes, higher-order Lamb modes have displacement nodes in the thickness direction, e.g., first-order antisymmetric (A1) [10], [32] first-order symmetrical (S1) [11], [33], and even higher-order Lamb modes [34], [35]. The operating frequencies of such modes are collectively determined by lateral and thickness dimensions [36], higher than fundamental modes in the same film stack with the same lateral wavelength.…”