A5052194021- Acoustic Wave Resonator Technologies
- Ferroelectric and Piezoelectric Materials
- Microwave Engineering and Waveguides
- Mechanical and Optical Resonators
- GaN-based semiconductor devices and materials
- Ultrasonics and Acoustic Wave Propagation
- Photorefractive and Nonlinear Optics
- Microwave and Dielectric Measurement Techniques
- Millimeter-Wave Propagation and Modeling
- Optical and Acousto-Optic Technologies
- Advanced MEMS and NEMS Technologies
The University of Texas at Austin
2022-2025
Summary This work reports a 50.74 GHz lithium niobate (LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) acoustic resonator with high quality factor (Q) of 237 and an electromechanical coupling (k <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 5.17% resulting in figure merit (FoM, Q•k 12.2. The LiNbO employs novel bilayer periodically poled piezoelectric film (P3F) 128º Y-cut on amorphous silicon (a-Si) sapphire stack to...
Piezoelectric resonators are a common building block for signal processing because of their miniature size, low insertion loss, and high quality factor. As consumer electronics push to millimeter waves frequencies, designers must increase the operating frequency resonator. The current state-of-the-art approach is decrease thickness piezoelectric film shorten acoustic wavelength or use higher order modes. Unfortunately, maintaining crystal typically requires thicker layers. Thinner layers...
This paper reports an acoustic resonator at 57 GHz with a high electromechanical coupling $(k^{2})$ of 7.3% and 3-dB quality factor (Q) 56, collectively enabling record-breaking Figure merit $(\mathrm{F}\mathrm{o}\mathrm{M},\ Q\cdot k^{2})$ 4.1, order magnitude higher than the state-of-the-art resonators. The device leverages third-order antisymmetric (A3) Lamb mode in 110 nm 128°Y-cut lithium niobate (LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML"...
This work reports an acoustic filter at 23.5 GHz with a low insertion loss (IL) of 2.38 dB and 3-dB fractional bandwidth (FBW) 18.2%, significantly surpassing the state-of-the-art. The device leverages electrically coupled resonators in 100 nm 128° Y-cut lithium niobate (LiNbO3) piezoelectric thin film, operating first-order antisymmetric (A1) mode. A new film stack, namely transferred thin-film LiNbO3 on silicon (Si) substrate intermediate amorphous (a-Si) layer, facilitates record-breaking...
This paper reports the first piezoelectric acoustic filter in periodically poled film (P3F) lithium niobate (LiNbO3) at 23.8 GHz with low insertion loss (IL) of 1.52 dB and 3-dB fractional bandwidth (FBW) 19.4%. The features a compact footprint 0.64 mm2. third-order ladder is implemented electrically coupled resonators 150 nm bi-layer P3F 128 rotated Y-cut LiNbO3 thin film, operating second-order symmetric (S2) Lamb mode. record-breaking performance enabled by platform, where films...
This work reports a millimeter wave (mmWave) thin-film bulk acoustic resonator (FBAR) in sputtered scandium aluminum nitride (ScAlN). paper identifies challenges of frequency scaling ScAlN into mmWave and proposes stack new fabrication procedure with Sc0.3 Al0.7 N on Al Si carrier wafer. The achieves electromechanical coupling ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${k} ^{2}$...
This work presents the first demonstration of a three layer periodically poled piezoelectric film (P3F) lithium niobate resonator. The proposed platform allows for high series 3dB quality factor (Q) resonances, including Q up to 811 at 12.98 GHz. trilayer stack employs use layers with alternating orientations on an intermediate amorphous bonding and sapphire substrate. enables order Lamb modes thanks comparatively large thickness when compared monolayer counterparts. shows ultra $f\dot Q$...
This study describes a sputtered scandium aluminum nitride (ScAlN) thin-film bulk acoustic resonator (FBAR) at 55.4 GHz. The leverages the third-order symmetric (S3) mode in 37 nm Al on 85 Sc <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.3</inf> xmlns:xlink="http://www.w3.org/1999/xlink">0.7</inf> N film stack, enabled by new fabrication procedure. GHz S3 tone achieves electromechanical coupling (k <sup...
This paper reports the first high-performance acoustic filters toward millimeter wave (mmWave) bands using transferred single-crystal thin film lithium niobate (LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ). By transferring LiNbO on top of silicon (Si) and sapphire (Al xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O ) substrates with an intermediate amorphous Si (aSi) bonding sacrificial layer, we demonstrate compact...
This paper reports the first groups of low-loss acoustic solidly mounted resonators (SMR) and delay lines (ADL) at 14-20 GHz. Bulk waves (BAW) are confined in thin-film scandium aluminum nitride (ScAlN) on top dielectric Bragg reflectors, consisting alternating silicon dioxide with tantalum pentoxide (Ta2O5/SiO2) or niobium (Nb2O5/SiO2) Si carrier wafers. Stack material parameters extracted via high-resolution X-ray diffraction (HRXRD) reflectivity (XRR). The simulation experiment show...
This work describes sputtered scandium aluminum nitride (ScAlN) thin-film bulk acoustic resonators (FBAR) at millimeter wave (mmWave) with high quality factor (Q) using platinum (Pt) electrodes. FBARs combinations of Pt and (Al) electrodes, i.e., Al top – bottom, are built to study the impact The FBAR bottom achieves electromechanical coupling (k <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) 1.8% Q 94 for third-order symmetric (S3)...
As 5G connectivity proliferates, signal processing applications at 6G centimeter bands have gained attention for urban wireless capacity expansion. At sub-5 GHz, acoustic resonators operating in the fundamental symmetric (S0) Lamb mode hold significant promise if frequency scaled to bands. Concurrently, lateral wavelength dependency and traveling wave nature of S0 enable monolithic multi-frequency fabrication, transversal filters, correlators, other compact components. In this work, we...
This paper reports the characterization of acoustic loss at millimeter-wave (mm-wave) in high-order bulk Lamb waves using delay lines (ADL). Using periodically poled piezoelectric film (P3F) lithium niobate (LiNbO3) ADL testbeds, propagation loss, group velocity, and quality factor (Q) thin-film are extracted up to 30 GHz. work also demonstrates viability employing modes for enabling frequency scaling devices without relying on ultra-thin films or fine lateral feature size. An resonator is...
This paper explores the feasibility and impact of frequency tuning suspended acoustic resonators through ion beam assisted argon gas cluster etching. To do so, groups first-order anti-symmetric (A1) mode laterally excited were first fabricated in 65.2 nm thick 128° Y-cut lithium niobate (LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) then trimmed equivalent time intervals. The resulting film thicknesses 57.0 nm, 49.6 41.7 nm....
Radio frequency (RF) acoustic resonators have long been used for signal processing and sensing. Devices that integrate benefit from their slow phase velocity (v <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> ), in the order of 3 to 10 km/s, which allows miniaturization device. Regarding subject small form factor, operate at so-called fundamental antisymmetric mode (A0), feature even slower v (1 km/s), smaller devices. This work reports...
This work reports a 50.74 GHz lithium niobate (LiNbO3) acoustic resonator with high quality factor (Q) of 237 and an electromechanical coupling (k2) 5.17% resulting in figure merit (FoM, Q x k2) 12.2. The LiNbO3 employs novel bilayer periodically poled piezoelectric film (P3F) 128 Y-cut on amorphous silicon (a-Si) sapphire stack to achieve low losses at millimeter wave (mm-wave). device also shows 159, k2 65.06%, FoM 103.4 for the 16.99 tone. result promising prospects P3F towards mm-wave...
In this work, a 38.7 GHz acoustic wave ladder filter exhibiting insertion loss (IL) of 5.63 dB and 3-dB fractional bandwidth (FBW) 17.6% is demonstrated, pushing the frequency limits thin-film piezoelectric technology. The achieves operating up to 5G millimeter (mmWave) range 2 (FR2) bands, by thinning LiNbO3 resonators sub-50 nm thickness. high electromechanical coupling (k2) quality factor (Q) first-order antisymmetric (A1) mode in 128 Y-cut lithium niobate (LiNbO3) collectively enable...
This letter reports the first piezoelectric acoustic filter in periodically poled film (P3F) lithium niobate (LiNbO3) at 23.8 GHz with low insertion loss (IL) of 1.52- and 3-dB fractional bandwidth (FBW) 19.4%. The features a compact footprint 0.64 mm2. third-order ladder is implemented electrically coupled resonators 150 nm bi-layer P3F 128° rotated <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Y$...
This work reports the first study of periodically poled piezoelectric film (P3F) lithium niobate (LiNbO3) resonators at cryogenic temperatures. We experimentally investigate temperature dependency resonant frequencies and quality factor (Q) higher-order Lamb modes up to 20 GHz between 80{\deg}K 297{\deg}K, using a tri-layer P3F LiNbO3 as experimental platform. The supported thickness-shear second-order symmetric (S2) eleventh-order antisymmetric (A11) show coefficients frequency (TCF)...