Ruochen Lu
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View article: Practical Demonstrations of FR3-Band Thin-Film Lithium Niobate Acoustic Filter Design
Practical Demonstrations of FR3-Band Thin-Film Lithium Niobate Acoustic Filter Design Open
This article presents an approach to control the operating frequency and fractional bandwidth (FBW) of miniature acoustic filters in thin-film lithium niobate (TFLN). More specifically, we used first-order antisymmetric (A1) mode lateral-f…
View article: 62.6 GHz ScAlN Solidly Mounted Acoustic Resonators
62.6 GHz ScAlN Solidly Mounted Acoustic Resonators Open
We demonstrate a record-high 62.6 GHz solidly mounted acoustic resonator (SMR) incorporating a 67.6 nm scandium aluminum nitride (Sc0.3Al0.7N) piezoelectric layer on a 40 nm buried platinum (Pt) bottom electrode, positioned above an acoust…
View article: Thermal Endurance of Suspended Thin-Film Lithium Niobate up to 800 °C
Thermal Endurance of Suspended Thin-Film Lithium Niobate up to 800 °C Open
The need for high-temperature piezoelectric microelectromechanical systems (MEMS) requires pushing piezoelectric platforms to their thermal limits. In harsh thermal environments, piezoelectric MEMS devices are expected to sustain severe da…
View article: An 11.7-GHz ScAlN FBAR Filter: Case Study on Scaling Limits and Challenges
An 11.7-GHz ScAlN FBAR Filter: Case Study on Scaling Limits and Challenges Open
This paper reports an 11.7 GHz compact 50 ohm ladder filter based on single layer Scandium Aluminum Nitride (ScAlN) film bulk acoustic resonators (FBARs) with platinum (Pt) electrodes, and uses it as a quantitative case study of the limits…
View article: Bimorph Lithium Niobate Piezoelectric Micromachined Ultrasonic Transducer
Bimorph Lithium Niobate Piezoelectric Micromachined Ultrasonic Transducer Open
This work demonstrates a prototype bi-layer piezoelectric micromachined ultrasonic transducer (PMUT) based on transferred periodically poled piezoelectric film (P3F) X-cut lithium niobate (LN). Opposite in-plane polarizations in the piezoe…
View article: High-Q Millimeter-Wave Acoustic Resonators in Thin-Film Lithium Niobate Using Higher-Order Antisymmetric Modes
High-Q Millimeter-Wave Acoustic Resonators in Thin-Film Lithium Niobate Using Higher-Order Antisymmetric Modes Open
This letter presents miniature millimeter wave (mmWave, above 30 GHz) acoustic resonators based on a single-layer thin-film lithium niobate (LN) platform. More specifically, we present high performance third-order antisymmetric (A3) mode l…
View article: Thermal Resilience of Suspended Thin-Film Lithium Niobate Acoustic Resonators up to 550 °C
Thermal Resilience of Suspended Thin-Film Lithium Niobate Acoustic Resonators up to 550 °C Open
This paper reports a suspended thin-film lithium niobate (LN) piezoelectric resonator platform surviving high annealing temperatures of 550 °C, among the highest temperature at which the thermal resilience of suspended LN resonators is stu…
View article: Ku-Band Alscn-on-Diamond SAW Resonators with Phase Velocity Above 8600 M/S
Ku-Band Alscn-on-Diamond SAW Resonators with Phase Velocity Above 8600 M/S Open
In this work, an Aluminum Scandium Nitride (AlScN) on Diamond Sezawa-mode surface acoustic wave (SAW) platform for RF filtering at Ku-band (12-18 GHz) is demonstrated. Thanks to the high acoustic velocity and low-loss diamond substrate, th…
View article: Lithium Tantalate Bulk Acoustic Resonator for Piezoelectric Power Conversion
Lithium Tantalate Bulk Acoustic Resonator for Piezoelectric Power Conversion Open
We present the first lithium tantalate (LT) thickness-extensional (TE) mode bulk acoustic resonators designed for piezoelectric power conversion, showcasing a low temperature coefficient of frequency (TCF) of -13.56 ppm/K. These resonators…
View article: 50 GHz Piezoelectric Acoustic Filter
50 GHz Piezoelectric Acoustic Filter Open
This paper presents significant frequency scaling of acoustic filter technology to 50 GHz. This achievement is enabled by the P3F LiNbO3 multilayer stack, in which piezoelectric thin-films of alternating orientations are transferred in seq…
View article: 19.3 GHz Acoustic Filter with High Close-in Rejection in Tri-layer Thin-Film Lithium Niobate
19.3 GHz Acoustic Filter with High Close-in Rejection in Tri-layer Thin-Film Lithium Niobate Open
Acoustic filters are preferred front-end solutions at sub-6 GHz due to their superior frequency selectivity compared to electromagnetic (EM) counterparts. With the ongoing development of 5G and the evolution toward 6G, there is a growing n…
View article: General Synthesis Methodology for Acoustic Wave Ladder Filters in the Bandpass Domain
General Synthesis Methodology for Acoustic Wave Ladder Filters in the Bandpass Domain Open
Altres ajuts: acords transformatius de la UAB
View article: Acoustic resonators above 100 GHz
Acoustic resonators above 100 GHz Open
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 …
View article: Lithium Niobate Resonators for Power Conversion: Spurious Mode Suppression Via an Active Ring
Lithium Niobate Resonators for Power Conversion: Spurious Mode Suppression Via an Active Ring Open
In an effort to shift the paradigm of power conversion, acoustic resonators pose as compact alternatives for lossy magnetic inductors. Currently, the acoustic resonator's restricted inductive region between its series and parallel resonanc…
View article: Low-Loss Higher-Order Cross-Sectional Lamé Mode SAW Devices in 10-20 GHz Range
Low-Loss Higher-Order Cross-Sectional Lamé Mode SAW Devices in 10-20 GHz Range Open
This paper presents surface acoustic wave (SAW) acoustic delay lines (ADL) for studying propagation loss mechanisms in Lithium Niobate (LN). Devices were fabricated by depositing 50 nm aluminum patterns on 600 nm X-Cut LN on amorphous sili…
View article: C-Band Lithium Niobate on Silicon Carbide SAW Resonator With Figure-of-Merit of 124 at 6.5 GHz
C-Band Lithium Niobate on Silicon Carbide SAW Resonator With Figure-of-Merit of 124 at 6.5 GHz Open
In this work, we demonstrate a C-band shear-horizontal surface acoustic wave\n(SH-SAW) resonator with high electromechanical coupling (kt2) of 22% and a\nquality factor (Q) of 565 based on a thin-film lithium niobate (LN) on silicon\ncarbi…
View article: 18 GHz Solidly Mounted Resonator in Scandium Aluminum Nitride on SiO2/Ta2O5 Bragg Reflector
18 GHz Solidly Mounted Resonator in Scandium Aluminum Nitride on SiO2/Ta2O5 Bragg Reflector Open
This work reports an acoustic solidly mounted resonator (SMR) at 18.64 GHz, among the highest operating frequencies reported. The device is built in scandium aluminum nitride (ScAlN) on top of silicon dioxide (SiO2) and tantalum pentoxide …
View article: Acoustic and Electromagnetic Co-Modeling of Piezoelectric Devices at Millimeter Wave
Acoustic and Electromagnetic Co-Modeling of Piezoelectric Devices at Millimeter Wave Open
This work reports the procedure for modeling piezoelectric acoustic resonators and filters at millimeter wave (mmWave). Different from conventional methods for lower frequency piezoelectric devices, we include both acoustic and electromagn…
View article: 2 to 16 GHz Fundamental Symmetric Mode Acoustic Resonators in Piezoelectric Thin-Film Lithium Niobate
2 to 16 GHz Fundamental Symmetric Mode Acoustic Resonators in Piezoelectric Thin-Film Lithium Niobate Open
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 hol…
View article: Ultra-Wideband Tapered Transducers in Thin-Film Lithium Niobate on Silicon Carbide
Ultra-Wideband Tapered Transducers in Thin-Film Lithium Niobate on Silicon Carbide Open
Acoustic devices offer significant advantages in size and loss, making them ubiquitous for mobile radio frequency signal processing. However, the usable bandwidth is often limited to the achievable electromechanical coupling, setting a har…
View article: Thin-Film Lithium Niobate on Insulator Surface Acoustic Wave Devices for 6G Centimeter Bands
Thin-Film Lithium Niobate on Insulator Surface Acoustic Wave Devices for 6G Centimeter Bands Open
In this work, we investigate the frequency scaling of shear-horizontal (S.H.)\nsurface acoustic wave (SAW) resonators based on a lithium niobate on insulator\n(LNOI) substrate into the centimeter bands for 6G wireless systems. Prototyped\n…
View article: Experimental Study of Periodically Poled Piezoelectric Film Lithium Niobate Resonator at Cryogenic Temperatures
Experimental Study of Periodically Poled Piezoelectric Film Lithium Niobate Resonator at Cryogenic Temperatures Open
This work reports the first study of periodically poled piezoelectric film (P3F) lithium niobate (LiNbO3) resonators at cryogenic temperatures. We experimentally investigate the temperature dependency of resonant frequencies and quality fa…
View article: 23.8-GHz Acoustic Filter in Periodically Poled Piezoelectric Film Lithium Niobate With 1.52-dB IL and 19.4% FBW
23.8-GHz Acoustic Filter in Periodically Poled Piezoelectric Film Lithium Niobate With 1.52-dB IL and 19.4% FBW Open
This paper reports the first piezoelectric acoustic filter in periodically\npoled piezoelectric film (P3F) lithium niobate (LiNbO3) at 23.8 GHz with low\ninsertion loss (IL) of 1.52 dB and 3-dB fractional bandwidth (FBW) of 19.4%.\nThe fil…
View article: A Stacked Piezoelectric Converter Using a Segmented IDT Lithium Niobate Resonator
A Stacked Piezoelectric Converter Using a Segmented IDT Lithium Niobate Resonator Open
Piezoelectric resonators promise to increase dc-dc converter power density by replacing inductive components. However, piezoelectric resonators are not direct circuit level replacements for inductors, requiring new topologies. In this pape…
View article: Millimeter Wave Thin-Film Bulk Acoustic Resonator in Sputtered Scandium Aluminum Nitride Using Platinum Electrodes
Millimeter Wave Thin-Film Bulk Acoustic Resonator in Sputtered Scandium Aluminum Nitride Using Platinum Electrodes Open
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 with combinations of Pt and aluminum (…
View article: Transferred Thin Film Lithium Niobate as Millimeter Wave Acoustic Filter Platforms
Transferred Thin Film Lithium Niobate as Millimeter Wave Acoustic Filter Platforms Open
This paper reports the first high-performance acoustic filters toward millimeter wave (mmWave) bands using transferred single-crystal thin film lithium niobate (LiNbO3). By transferring LiNbO3 on the top of silicon (Si) and sapphire (Al2O3…
View article: 38.7 GHz Thin Film Lithium Niobate Acoustic Filter
38.7 GHz Thin Film Lithium Niobate Acoustic Filter Open
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) of 17.6% is demonstrated, pushing the frequency limits of thin-film piezoelectric acoustic filter technology…
View article: Thin-Film Lithium Niobate Acoustic Filter at 23.5 GHz With 2.38 dB IL and 18.2% FBW
Thin-Film Lithium Niobate Acoustic Filter at 23.5 GHz With 2.38 dB IL and 18.2% FBW Open
This work reports an acoustic filter at 23.5 GHz with a low insertion loss (IL) of 2.38 dB and a 3-dB fractional bandwidth (FBW) of 18.2%, significantly surpassing the state-of-the-art. The device leverages electrically coupled acoustic re…
View article: Millimeter Wave Thin-Film Bulk Acoustic Resonator in Sputtered Scandium Aluminum Nitride
Millimeter Wave Thin-Film Bulk Acoustic Resonator in Sputtered Scandium Aluminum Nitride Open
This work reports a millimeter wave (mmWave) thin-film bulk acoustic resonator (FBAR) in sputtered scandium aluminum nitride (ScAlN). This paper identifies challenges of frequency scaling sputtered ScAlN into mmWave and proposes a stack an…