Bio-Electronics and RFIC (BEaR) Lab — PI: V. Leung, PhD.
Journals and Conferences
2024
[50] C. M. Thomas, M. Abderezai, L. Dong and V. Leung, “An All-Digital Synthesizer Enabled by a Convolutional Neural Network ,” 2024 IEEE/MTT-S International Microwave Symposium – IMS 2024 , Washington, DC, USA, 2024, pp. 94-97.
[49] Lee, J., Lee, AH., Leung, V ., Laiwalla F., Lopez-Gordo M. A., Larson L., Nurmikko A. An asynchronous wireless network for capturing event-driven data from large populations of autonomous sensors . Nature Electronics (2024).
[48] Abbasi, S.; Alluri, S.; Leung, V. ; Asbeck, P.; Makale, M.T. Design and Validation of Miniaturized Repetitive Transcranial Magnetic Stimulation (rTMS) Head Coils . Sensors 2024, 24 , 1584.
[47] S. Alluri, V. Leung and P. Asbeck, “A compact 27 dBm triple-stack power amplifier for 13 GHz operation in CMOS-SOI ,” 2024 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) , San Antonio, TX, USA, 2024, pp. 13-16.
2023
[46] V. W. Leung , A. Lee, J. Lee, S. Alluri, J. Alonzo, L. Mello, B. Beyer, D. Durfee, W. A. Lau, P. Asbeck, L. Larson, F. Laiwalla, A. Nurmikko, “Improving Wireless Power Transfer Efficiency for Distributed Brain Implants Using Auto-Tune OVP ,” 2023 IEEE Biomedical Circuits and Systems Conference (BioCAS) , Toronto, ON, Canada, 2023, pp. 1-5.
[45] A. Lee, J. Lee, V. W. Leung , S. Cash, A. Nurmikko, “Minimally Invasive Subdermal Wireless EEG Sensor Arrays for Home Monitoring of Epilepsy ,” 2023 IEEE Biomedical Circuits and Systems Conference (BioCAS) , Toronto, ON, Canada, 2023, pp. 1-5.
[44] J. Lee, A. Lee, V. W. Leung , F. Laiwalla, M. Lopez-Gordo, L. Larson, A. Nurmikko, “Asynchronous Wireless Network for Transmission of Neural Data from Thousands of Autonomous Microimplants ,” 2023 IEEE Biomedical Circuits and Systems Conference (BioCAS) , Toronto, ON, Canada, 2023, pp. 1-5.
[43] A.-H. Lee, J. Lee, V. Leung , A. Nurmikko, “Versatile On-Chip Programming of Circuit Hardware for Wearable and Implantable Biomedical Microdevices ,” Adv. Sci. 2023, 2306111.
[42] P. M. Asbeck, S. Alluri, V. Leung , S. Abbasi and M. T. Makale, “An Efficient Circuit for Pulsed Magnetic Neural Stimulation,” in IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology , June 2023.
[41] S. Abbasi, B. Joray, K. Rudnicki, V. Leung , P. Asbeck and M. Makale, “Coil Size and Current Pulse Optimization through Multi-Scale Modeling for Repetitive Transcranial Magnetic Stimulation (rTMS),” 2023 11th International IEEE/EMBS Conference on Neural Engineering (NER) , Apr. 2023.
[40] R. Zhao, K. Wang, K. Zheng, X. Zhang and V. Leung , “SlimWiFi: Ultra-Low-Power IoT Radio Architecture Enabled by Asymmetric Communication,” 20th USENIX Symp. on Networked Systems Design and Implementation (NSDI 23) , Apr. 2023.
2022
[39] K. Wang, S. Alluri, X. Zhang and V. W. Leung , “A Sub-100μW 2GHz OOK PA for IoT Applications,” 2022 IEEE Texas Symposium on Wireless and Microwave Circuits and Systems (WMCS) , Apr. 2022.
[38] S. Alluri, N. Rostomyan, V. Leung and P. Asbeck, “A Ka Band Power Amplifier with Varactor-Based Analog Predistortion in pMOS-SOI,” 2022 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) , Apr. 2022.
2021
[37] P. Asbeck, S. Alluri, V. Leung , M. Stambaugh, S. Abbasi, M. Makale, “A compact circuit for boosting electric field intensity in repetitive magnetic stimulation (rTMS),” Int. Conf. of the IEEE Engineering in Medicine & Biology Society (EMBC) , Nov. 2021.
[36] J. Lee, V. Leung , A. Lee, J. Huang, P. Asbeck, P. Mercier, S. Shellhammer, L. Larson, F. Faiwalla, A. Nurmikko, “Neural recording and stimulation using wireless networks of microimplants,” Nature Electronics , Aug. 2021.
[35] A. Huang, W. Connacher, M. Stambaugh, N. Zhang, S. Zhang, J. Mei, A. Jain, S. Alluri, V. Leung , A. Rajapaksa, J. Friends, “Practical microcircuits for handheld acoustofluidics,” Lab on a Chip , January 2021.
2020 (Pre-Baylor)
[34] Lee, A.-H.; Lee, J.; Laiwalla, F.; Leung, V .; Huang, J.; Nurmikko, A.; Song, Y.-K. “A scalable and low Stress Post-CMOS Processing Technique for Implantable Microsensors ,” Micromachines, Oct. 2020.
[33] K. Wang, L. Yao, M. Jahon, J. Liu, M. Gonzalez, P. Liu, V. Leung , X. Zhang, T. N. Ng, “Ion-exchange separators suppressing self-discharge in polymeric supercapacitors ,” ACS Energy Letters, Sept, 2020.
[32] V. Leung , M. Stambaugh, S. Abbasi, P. Asbeck, D. Gough, M. Makale, K. T. Murphy, “A compact battery-powered rTMS prototype ,” Int. Conf. of the IEEE Engineering in Medicine & Biology Society (EMBC) , July 2020.
[31] F. Laiwalla, J. Lee, A. Lee, E. Mok, V. Leung , S. Shellhammer, Y. Song, L. Larson and A. Nurmikko, “A distributed wireless network of implantable sub-mm cortical microstimulators for brain-computer interfaces ”, Int. Conf. of IEEE Engineering in Medicine and Biology Conference (EMBC) , July 2019.
[30] V. Leung , L. Cui, S. Alluri, J. Lee, J. Huang, E. Mok, S. Shellhammer, R. Rao, P. Asbeck, P. Mercier, L. Larson, A. Nurmikko, F. Laiwalla, “Distributed microscale brain implants with wireless power transfer and Mbps bi-directional networked communications”, IEEE Custom Integrated Circuits Conf. (CICC ), April 2019.
[29] J. Lee, E. Mok, J. Huang, L. Cui, A. Lee, V. Leung , P. Mercier, S. Shellhammer, L. Larson, P. Asbeck, R. Rao. Y. Song, A. Nurmikko, F. Laiwalla, “An implantable wireless network of distributed microscale sensors for neural applications,” Int. IEEE EMBS Conf. on Neural Engineering (NER) , Mar. 2019.
[28] J. Jeong, F. Laiwalla, J. Lee, R. Ritasalo, M. Oudas, L. Larson, V. Leung , A. Nurmikko, “Conformal hermetic sealing of wireless microelectronic implantable chiplets by multilayered atomic layer deposition (ALD)”, Advanced Functional Materials , vol. 29, issue 5, Dec. 2018.
[27] J. Lee, F. Laiwalla, J. Jeong, C. Kilfoyle, L. Larson, A. Nurmikko, S. Li, S. Yu, V. Leung , “Wireless power and data link for ensembles of sub-mm scale implantable sensors near 1GHz ,” IEEE Biomedical Circuits and Systems Conference (BioCAS) , Oct. 2018.
[26] H. Cai, M. Lokhandwala, J. Zhu, C. Kilfoyle, L. Larson, A. Nurmikko, F. Laiwalla, V. Leung , “Demo: A software-defined radio for wireless brain implants networks ,” Proc. Int. Conf. on Mobile Computing and Networking (MobiCom ’18) , ACM, Oct. 2018.
[25] V. Leung , J. Lee, S. Li, S. Yu, C. Kilfoyle, L. Larson, A. Nurmikko, F. Laiwalla, “A CMOS distributed sensor system for high-density wireless neural implants for brain-machine interfaces ,” IEEE European Solid-State Circuits Conf. (ESSCIRC) , Sept. 2018.
[24] J. Huang, F. Laiwalla, J. Lee, L. Cui, V. Leung , A. Nurmikko, P. Mercier, “A 0.01mm2 mostly digital capacitor-less AFE for distributed autonomous neural sensor nodes”, IEEE Solid-State Circuits Letters , vol. 1, no. 7, July 2018.
[23] H. Gheidi, T. Nakatani, V. Leung , P. Asbeck, “A 1-3 GHz delta-sigma-based closed-loop fully digital phase modulator in 45nm CMOS SOI ”, J. of Solid-State Circuits , vol. 52, May 2017.
[22] H. Gheidi, T. Nakatani, V. Leung , P. Asbeck, “A wideband delta-sigma based closed-loop fully digital phase modulator in 45nm CMOS SOI ”, IEEE RFIC Symp , May 2016.
[21] C. Thomas, V. Leung , L. Larson, “A pseudorandom clocking scheme for a CMOS N-path bandpass filter with 10-to-15 dB spurious leakage improvement,” Proc. IEEE Radio and Wireless Symp. , Jan. 2015.
[20] T. Nakatani, H. Gheidi, V. Leung , D. Kimball, P. Asbeck, “Signal generation algorithm for digital polar transmitters with reduced receive band noise ,” IEEE Topical Conf. on PA for Wireless and Radio Applications (PAWR) , Jan. 2014.
[19] M. Hassan, L. E. Larson, V. W. Leung , D. F. Kimball and P. M. Asbeck, “A Wideband CMOS/GaAs HBT Envelope Tracking Power Amplifier for 4G LTE Mobile Terminal Applications ,” in IEEE Transactions on Microwave Theory and Techniques , vol. 60, no. 5, May 2012.
[18] M. Hassan, L. Larson, V. Leung , P. Asbeck, “A combined series-parallel hybrid envelope amplifier for envelope tracking mobile terminal RF power amplifier applications ,” J. of Solid-State Circuits , vol. 47, May 2012.
[17] M. Hassan, L. E. Larson, V. W. Leung and P. M. Asbeck, “Effect of envelope amplifier nonlinearities on the output spectrum of Envelope Tracking Power Amplifiers ,” 2012 IEEE 12th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems , Santa Clara, CA, USA, 2012.
[16] M. Hassan, M. Kwak, V. Leung , C. Hsia, J. Yan, D. Kimball, L. Larson, P. Asbeck, “High efficiency envelope tracking power amplifier with very low quiescent power for 20 MHz LTE ,” RFIC Symp. Dig. of Papers ., pp. 1-4, June 2011.
[15] Y. Tang, M. Chen, W. Leung , C. Narathong, M. Ranjan, K. Godbole, G. Zhang, O. Choksi, V. Panikkath, C. Holenstein, A. Hadjichristos, K. Sahota, “A configurable multi-band multi-mode transmitter with spur cancellation through digital baseband ,” Dig. Tech. Papers Symp. of VLSI Circuits , June 2011.
[14] S. Park, V. Leung , and L. Larson, “An improved wide-dynamic range tunable RF interference suppression notch filter ,” Proc. IEEE ISCAS, May 2010.
[13] V. Leung , J. Deng, P. Gudem and L. Larson, “Analysis of envelope signal injection for improvement of RF amplifier intermodulation distortion ,” IEEE J. of Solid-State Circuits , vol. 40, Sept. 2005.
[12] V. Leung , L. Larson and P. Gudem, “An improved digital-IF transmitter architecture for highly-integrated W-CDMA mobile terminals ,” IEEE Trans. on Vehicular Tech ., vol. 54, Jan. 2005.
[11] V. Leung , L. Larson and P. Gudem, “Digital-IF WCDMA handset transmitter IC in 0.25um SiGe BiCMOS ,” IEEE J. of Solid-State Circuits , vol. 39, Dec. 2004.
[10] V. Leung , J. Deng, P. Gudem and L. Larson, “Analysis of envelope signal injection for improvement of RF amplifier intermodulation distortion ,” Proc. IEEE Custom Integrated Circuit Conf ., Oct. 2004.
[9] V. Leung , L. Larson and P. Gudem, “Digital-IF WCDMA handset transmitter IC in 0.25um SiGe BiCMOS ,” ISSCC Dig. Tech. Papers , Feb. 2004.
[8] V. Leung , L. Larson and P. Gudem, “An improved digital-IF transmitter architecture for highly-integrated W-CDMA mobile terminals ,” Proc. IEEE 57th Vehicular Tech. Conf ., vol. 2, Apr. 2003.
[7] B. Song, V. Leung , T. Cho, D. Kang and S. Dow, “A 2.4GHz Bluetooth transceiver in 0.18um CMOS ,” Proc. 2002 IEEE Asia-Pacific Conferenceon ASIC , Aug. 2002.
[6] J. Guido, V. Leung , J. Kenney, J. Trackim, A. Agrillo, E. Zimany and R. Shariatdoust, “Analog front end IC for category I & II ADSL ,” Dig. Tech. Papers Symp. of VLSI Circuits , June 2000.
[5] J. Kenney, F. Sabouri, V. Leung , J. Guido, E. Zimany, A. Agrillo, J. Trackim, J. Khoury and R. Shariatdoust, “A 4 channel analog front end for central office ADSL modems ,” Proc. IEEE Custom IC Conf. , May 2000.
[4] V. Leung , and G. Roberts, “Effects of transistor nonidealities on high order log-domain ladder filter frequency response ,” IEEE Trans. Circuits and Syst II , vol. 47, May 2000.
[3] V. Leung and G. Roberts, “Analysis and compensation of log-domain biquadratic filter responses deviations due to transistor nonidealities ,” Int. Journal of Analog IC and Signal Processing , vol. 22, no. 2/3, Mar. 2000.
[2] M. El-Gamal, V. Leung , and G. Roberts, “Balanced log-domain filters for VHF applications,” Proc. IEEE ISCAS , June 1997.
[1] V. Leung , M. El-Gamal, and G. Roberts, “Effects of transistor nonidealities on Log-Domain Filters,” Proc. IEEE ISCAS , June 1997.
Patents
[16] K. Murphy, V. Leung , P. Asbeck, M. Stambaugh, M. Makale, D. Gough, “Compact battery-powered repetitive transcranial magnetic stimulation ”, USPTO App. 18/005,811 , 2023. (pending)
[15] P. M. Asbeck, F. Laiwalla, V. W. Leung , J. Lee, L. E. Larson, P. Mercier, A. Nurmikko, R. Rao, “High density neural implants for brain-machine interface “, USPTO App. 17/260,903 , 2021. (pending)
[14] A. Nurmikko, F. Laiwalla, J. Lee, V. W. Leung , P. Mercier, L. E. Larson, P. M. Asbeck, “Implantable wireless network of distributed microscale sensors “, USPTO App. 16/879,216 , 2020. (pending)
[13] A. Youssef, W. Leung , R. Xu, U. Fernando, K. Humnabadkar, T. Huang, L. Chang, “Multi-stage amplifier with RC network” , US Patent 9723560 , Aug. 2017.
[12] S. Woo, W. Leung , L. Chang, “Cross-connected cascode LNA for CA application” , US Patent 9642166 , May 2017.
[11] M. Uzunkol, R. Xu, A. Youssef, W. Leung , E. Abdel Ghany, A. He. S. Woo, L. Chang, “Spurious signal mitigation for carrier aggregation amplifier” , US Patent 9425746 , Aug. 2016.
[10] R. Xu, A. He, W. Leung , A. Youssef, E. Abdel Ghany, S. Woo, L. Chang, “Single-input-multi-output amplifiers with simultaneous multiple gain mode” , US Patent 9467104 , Oct. 2016.
[9] A. Youssef, M. Uzunkol, R. Xu, E. Abdel Ghany, W. Leung , S. Woo, A. He, L. Chang, “Inter carrier-aggregation isolation in a receiver” , US Patent 9425832 , Apr. 2016.
[8] A. Youssef, L. Chang, E. Abdel Ghany, R. Xu, W. Leung , A. He, “Routing and shielding of signal lines to improve isolation” , US Patent 9277641 , March 2016.
[7] E. Abdel Ghany, S. Woo, W. Leung , Z. Jin, L. Chang, “Area-efficient degenerative inductance for a low noise amplifier (LNA)” , US Patent 9130529 , Sept. 2015.
[6] C. Holenstein, A. Tasic, L. Chang, A. He, R. Xu, E. Abdel Ghany, W. Leung , A. Youssef, S. Woo, “Single-input multiple-output amplifiers with independent gain control per output” , US Patent 8903343 , Dec. 2014.
[5] W. Leung , Z. Yang, “Dividing a frequency by 1.5 to produce a quadrature signal” , US Patent 8803568 , Aug. 2014.
[4] P. Gudem, B. Asuri, S. Lau, W. Leung , “Reducing power consumption by in-circuit measurement of receive band attenuation and/or noise” , US Patent 8774874 , July 2014.
[3] L. Lim, D. Pehlke, J. Khoury and V. Leung , “Power control scheme for a power amplifier” , US Patent 7974596, July 2011.
[2] V. Leung , P. Gudem and L. Larson, “Adaptive bias current and method for amplifiers” , US Patent 7567123 , July 2009.
[1] V. Leung , J. Khoury and R. Shariatdoust, “Integrated analog adaptive equalizer” , US Patent 6542540 , Mar. 2003
Book Chapters & Book
Laiwalla F, Leung V , Larson L, Nurmikko A. (2023). Challenges for Large Scale Brain-Machine Interfaces . In: Thakor, N.V. (eds) The Handbook of Neural Engineering , Springer.
Laiwalla F, Leung V , Lee J, Mercier P, Asbeck P, Rao R, Larson L, Nurmikko A. (2021) Next generation Microscale Wireless Implant System for High-density, Multi-Areal, Closed-Loop Brain Computer Interfaces . In: Guger C. et al., (eds) Brain-Computer Interface Research: A State-of-the-Art Summary , Springer.
Leung V. W., Roberts G. W. (2000) Analysis and Compensation of Log-Domain Biquadratic Filter Response Deviations due to Transistor Nonidealities . In: Serdijn W.A., Mulder J. (eds) Research Perspectives on Dynamic Translinear and Log-Domain Circuits . The Springer International Series in Engineering and Computer Science (Analog Circuits and Signal Processing), vol 550. Springer..
V. Leung and G. Roberts, Design and Analysis of Integrator-Based Log-Domain Filter Circuits , Kluwer Academic Publishers, Dordrecht, the Netherlands, 2000. (280 pages. Foreword by Robert Adams, Analog Devices Fellow and inventor of log-domain filters.)