Publications and Presentations

First Author Papers/Conference Proceedings:

1. J. Kramer, R. Lu, "A generalized acoustic framework for multilayer piezoelectric platforms", IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2025

2. J. Kramer, B. T. Bosworth, L. Matto, N. R. Jungwirth, O. Barrera, F. Bergmann, S. Cho, V. Chulukhadze, M. Goorsky, N. D. Orloff, R. Lu, "Acoustic resonators above 100 GHz", Applied Physics Letters, July 2025

3. J. Kramer, O. Barrera, S. Cho, V. Chulukhadze, T.-H. Hsu, R. Lu, “Experimental Study of Periodically Poled Piezoelectric Film Lithium Niobate Resonator at Cryogenic Temperatures”, IEEE International Microwave Symposium (IMS), June 2024.

4. J. Kramer, T.-H. Hsu, J. Campbell, R. Lu, “Ultra-Wideband Tapered Transducers in Thin-Film Lithium Niobate on Silicon Carbide”, Hilton Head Workshop, June 2024.

5. J. Kramer, K. Huynh, R. Tetro, L. Matto, O. Barrera, V. Chulukhadze, D. Luccioni, L. Colombo, M. Goorsky and R. Lu, “Trilayer Periodically Poled Piezoelectric Film Lithium Niobate Resonator”, IEEE International Ultrasonics Symposium (IUS), September 2023.

6. J. Kramer, M. E. Liao, S. Cho, K. Huynh, O. Barrera, L. Matto, M. Goorsky, and R. Lu, “Study of Acoustic Loss at Millimeter-Wave in Thin Film Lithium Niobate,” IEEE International Microwave Symposium (IMS), June 2023.

7. Jack Kramer, Vakhtang Chulukhadze, Kenny Huynh, Omar Barrera, Michael Liao, Sinwoo Cho, Lezli Matto, Mark S. Goorsky and Ruochen Lu, “Thin-Film Lithium Niobate Acoustic Resonator with High Q of 237 and k2 of 5.1% at 50.74 GHz,” IEEE International Frequency Control Symposium (IFCS), May 2023. (Best Student Paper Award)

8. J. Kramer, M. E. Liao, S. Cho, K. Huynh, O. Barrera, L. Matto, M. Goorsky, and R. Lu, “57 GHz Acoustic Resonator with k2 of 7.3% and Q of 56 in Thin-Film Lithium Niobate,” IEEE International Electron Devices Meeting (IEDM), December 2022.

9. J. Kramer, D. Lee, S. Cho, S. Jahanbani, K. Lai, and R. Lu, “Acoustic Wave Focusing Lens at Radio Frequencies in Thin-Film Lithium Niobate,” International Conference on Microwave Acoustics & Mechanics (IC-MAM), July 2022. (Best Student Paper Award)

Coauthored Author Papers/Conference Proceedings: 

1. V Chulukhadze, Y Wang, I Anderson, J Kramer, S Cho, R Lu, "Miniature High-Coupling Lithium Niobate Thin Film Bulk Acoustic Wave Resonators at 10-30 GHz", IEEE/MTT-S International Microwave Symposium-IMS 2025 

2. O Barrera, T Anusorn, S Cho, J Kramer, V Chulukhadze, TH Hsu, J. Campbell, I. Anderson, R. Lu, "Frequency and Bandwidth Design Toward Millimeter-Wave Thin-Film Lithium Niobate Acoustic Filters", IEEE Microwave and Wireless Technology Letters, May 2025

3. I. Anderson, O. Barrera, N. Ravi, L. Matto, K. Saha, S. Dasgupta, J. Campbell, J. Kramer, E. Kwon, T.-H. Hsu, S. Cho, P. Simeoni, J. Hou, M. Rinaldi, M. S Goorsky, R. Lu, "Solidly Mounted Scandium Aluminum Nitride on Acoustic Bragg Reflector Platforms at 14-20 GHz", IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, March 2025

4. SY Huang, ZQ Lee, TH Hsu, J Campbell, J Kramer, R Lu, MH Li, "A 4.3 GHZ Lithium Niobate on Insulator Wideband Surface Acoustic Wave Delay Line with Multi-Mode Composition"

5. Z.Q. Lee, S.Y. Huang, T.H. Hsu, J. Campbell, J. Kramer, R. Lu, M.H. Li, "6 GHz Lithium Niobate on Insulator Low-Loss Saw Delay Line Adapting Non-Leaky Composite Waveguide Mode" 2025 IEEE 38th International Conference on Micro Electro Mechanical Systems (MEMS) 2025

6. J Campbell, TH Hsu, L Matto, N Ahmed, M Chaudhari, Z Du, I Anderson, J. Kramer, V. Chulukhadze, K. Chow, M.-H. Li, M. S Goorsky, R. Lu, "52 GHz surface acoustic wave resonators in thin film lithium niobate on silicon carbide", IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, December 2024

7. O. Barrera, N. Ravi, K. Saha, S. Dasgupta, J. Campbell, J. Kramer, E. Kwon, T.-H. Hsu, S. Cho, I. Anderson, P. Simeoni, J. Hou, M. Rinaldi, M. S Goorsky, R. Lu, “18 GHz Solidly Mounted Resonator in Scandium Aluminum Nitride on SiO2/Ta2O5 Bragg Reflector”, IEEE Journal of Micro-Electromechanical Systems (JMEMS), October 2024.

8. T. Zhang, Y.-W. Chang, O. Barrera, N. Ahmed, J. Kramer, and R. Lu, “Acoustic and Electromagnetic Co-Modeling of Piezoelectric Devices at Millimeter Wave”, IEEE Journal of Micro-Electromechanical Systems (JMEMS).

9. T.-H. Hsu, J. Campbell, J. Kramer, S. Cho, M.-H. Li, R. Lu, “C-Band Lithium Niobate on Silicon Carbide Surface Acoustic Wave Resonator with Figure-of-Merit of 124 at 6.5 GHz”, IEEE Journal of Micro-Electromechanical Systems (JMEMS), July 2024.

10. V. Chulukhadze, J. Kramer, T.-H. Hsu, O. Barrera, I. Anderson, S. Cho, J. Campbell, R. Lu, “2 to 16 GHz Fundamental Symmetric Mode Acoustic Resonators in Piezoelectric Thin-Film Lithium Niobate”, Hilton Head Workshop, June 2024.

11. T.-H. Hsu, J. Campbell, J. Kramer, S. Cho, Z.-Q. Lee, M.-H. Li, R. Lu, “Thin-film Lithium Niobate on Insulator Surface Acoustic Wave Devices for 6G Centimeter Bands”, IEEE International Conference on Microwave Acoustics & Mechanics (IC-MAM), May 2024.

12. S. Cho, O. Barrera, J. Kramer, V. Chulukhadze, T.-H. Hsu, J. Campbell, I. Anderson, R. Lu, “23.8-GHz acoustic filter in periodically poled piezoelectric film lithium niobate with 1.52-dB IL and 19.4% FBW”, IEEE Microwave and Wireless Technology Letters, March 2024.

13. O. Barrera, S. Cho, J. Kramer, V. Chulukhadze, J. Campbell, R. Lu, “38.7 GHz thin film lithium niobate acoustic filter”, 2024 IEEE International Microwave Filter Workshop (IMFW), February 2024.

14. O. Barrera, S. Cho, K. Hyunh, J. Kramer, M. Liao, V. Chulukhadze, L. Matto, M. S. Goorsky, R. Lu, “Transferred thin film lithium niobate as millimeter wave acoustic filter platforms”, IEEE International Conference on Micro Electro Mechanical Systems (MEMS), January 2024.

15. S. Cho, O. Barrera, P. Simeoni, E. Y. Wang, J. Kramer, V. Chulukhadze, J. Campbell, M. Rinaldi, R. Lu , “Millimeter wave thin-film bulk acoustic resonator in sputtered scandium aluminum nitride using platinum electrodes”, IEEE International Conference on Micro Electro Mechanical Systems (MEMS), January 2024.

16. S. Cho, O. Barrera, P. Simeoni, E. N. Marshall, J. Kramer, K. Motoki, T.-H. Hsu, V. Chulukhadze, M. Rinaldi, W. A. Doolittle, R. Lu, “Millimeter wave thin-film bulk acoustic resonator in sputtered scandium aluminum nitride” IEEE Journal of Micro-Electromechanical Systems (JMEMS), December 2023.

17. O. Barrera, S. Cho, L. Matto, J. Kramer, K. Huynh, V. Chulukhadze, Y.-W. Chang, M. S. Goorsky, R. Lu, “Thin-Film Lithium Niobate Acoustic Filter at 23.5 GHz with 2.38 dB IL and 18.2% FBW”, IEEE Journal of Micro-Electromechanical Systems (JMEMS), September 2023.

18. S. Cho, O. Barrera, P. Simeoni, E. N. Marshall, J. Kramer, K. Motoki, T.-H. Hsu, V. Chulukhadze, M. Rinaldi, W. A. Doolittle, R. Lu, “Millimeter Wave Thin-Film Bulk Acoustic Resonator in Sputtered Scandium Aluminum Nitride”, IEEE Journal of Micro-Electromechanical Systems (JMEMS), September 2023.

19. O. Barrera, J. Kramer, R. Tetro, S. Cho, V. Chulukhadze, L. Colombo and R. Lu, “Fundamental Antisymmetric Mode Acoustic Resonator in Periodically Poled Piezoelectric Film Lithium Niobate”, IEEE International Ultrasonics Symposium (IUS), September 2023.

20. V. Chulukhadze, J. Kramer, N. Ahmed, O. Barrera, S. Cho, and Ruochen Lu, “Frequency Tuning of Suspended Millimeter Wave Lithium Niobate Acoustic Resonators by Ion Beam Assisted Argon Gas Cluster Trimming”, IEEE International Ultrasonics Symposium (IUS), September 2023.

21. S. Cho, O. Barrera, P. Simeoni, J. Kramer, V. Chulukhadze, W. Zhao, and R. Lu, “28.4 GHz Bulk Acoustic Resonator in Thin-Film Scandium Aluminum Nitride,” IEEE International Ultrasonic Symposium (IUS), 2023.

22. V. Chulukhadze, K. Huynh, J. Kramer, M. Liao, S. Cho, L. Matto, O.  Barrera, C. Cui, M. Goorsky, and R. Lu, “Frequency Scaling Millimeter Wave Acoustic Devices in Thin Film Lithium Niobate,” IEEE International Frequency Control Symposium (IFCS), May 2023.

23. S. Cho, J. Guida, J. Kramer, O. Barrera, V. Chulukhadze, C. Cui, S. Ghosh, and R. Lu, “Analysis of 5-10 GHz Higher Order Lamb Acoustic Waves in Thin Film Scandium Aluminum Nitride,” IEEE International Frequency Control Symposium (IFCS), May 2023.

24. D. Lee, S. Jahanbani, J. Kramer, R. Lu, K. Lai, “Nanoscale Imaging of Super-high-frequency Microelectromechanical Resonators with Femtometer Sensitivity,” Nature Communications, March 2023.

25. S. Cho, Y. Wang, J. Kramer, K. Nguyen, and R. Lu, “Acoustic Delay Lines in Thin-Film Lithium Niobate on Silicon Carbide,” IEEE International Microwave Symposium (IMS), June 2022.