Justin B. King, Gian Piero Gibiino
©SHUTTERSTOCK.COM/ANDREY_POPOV
The first IEEE Young Professional Workshop on Modeling and Optimization for Active Devices took place on 25 October 2022, as a virtual event on Zoom.
This workshop, supported by the Technical Committee 2 (TC-2) on Design Automation, was endorsed by the IEEE Microwave Theory and Technology Society (MTT-S) and the IEEE Young Professionals (YPs). Trinity College Dublin, Ireland, and the University of Bologna, Italy, provided organizational support.
The event was primarily targeted at YPs and Ph.D./early-career stage researchers from academia or industry. The aim of the workshop was to provide a platform for the discussion of recent and prospective trends in the field of RF active device modeling and related optimization techniques. These research themes are identified by TC-2 as key to this field, as recently outlined in [1]. The workshop was promoted through social media channels (see Figure 1 for the advertisement banner used). To gain access to the workshop, online registration was required, with participation free of charge.
Figure 1. The workshop advertisement banner.
The workshop was divided into two live presentation sessions, one in the morning (10:00–12:00 UTC) and one in the afternoon (14:00–16:00 UTC). Each session consisted of four presentations, delivered by invited YP speakers, with a duration of 25 min per presentation, including a Q&A immediately following each presentation.
The YP speakers were invited based on their research activity on relevant topics (as outlined in the references). The morning session focused primarily on transistor-level modeling, with the initial presentations, by Ph.D. student Petros Beleniotis (Brandenburg University of Technology, Germany) and Dr. Luis Nunes (University of Aveiro, Portugal), focusing on the modeling of trapping effects in gallium nitride (GaN) HEMTs [2], [3]. The final two presentations, by Dr. Sachin Yadav (imec, Belgium) and Dr. Nicholas C. Miller (Air Force Research Laboratory, USA), were dedicated to process technology developments and technology computed aided design (TCAD)-based modeling techniques [4], [5].
The afternoon session focused on system-level nonlinear modeling techniques, specifically targeting power amplifiers (PAs). The first presentation, given by master’s student Xiaoqiang Tang (Hangzhou Dianzi University, China), provided an overview of behavioral modeling approaches, and the second presentation, by Dr. Lida Kouhalvandi (Dogus University, Turkey), addressed model-based optimization methods for power amplifier (PA) design [6]. The final two presentations, given by Ph.D. students Mattia Mengozzi (University of Bologna, Italy) and Wantao Li (Universitat Politècnica de Catalunya, Spain), covered digital predistortion and optimization-based techniques tailored to multiple-input PAs [7], [8].
Questions for the Roundtable Technical Discussion
In between the presentation sessions were two live and interactive panel sessions, with the panel formed by seven experts from the MTT-S community. (See “Expert Panelists.”)
Expert Panelists
The first of these sessions involved a roundtable discussion with three topical questions put to the panel, as shown in “Questions for the Roundtable Technical Discussion.”
This session generated several interesting discussions, with a consensus that many developments are to come in modeling, optimization, and active devices, although it is too early to be certain about future dominant device technologies. The panel was excited about the developments in artificial intelligence/machine learning (AI/ML), although a word of caution was provided on applying ML techniques to situations where alternative, robust, and reliable models already exist that can provide useful insight that many AI/ML-based models cannot.
The second panel session took the form of a career advice platform for YPs. The following questions were posed to the panel. (See “Questions for the Career Advice Panel.”)
Questions for the Career Advice Panel
The main advice from the panel to YPs was to get involved in the MTT-S community. This could take the form of attending conferences regularly as well as seeking collaboration. One specific piece of advice focused on finding your own path through the research landscape and to not be too concerned with following the latest trends.
In total, there were more than 200 registrants with a peak of approximately 70 simultaneous active participants throughout the course of the workshop. A snapshot of attendees is provided in Figure 2. Despite the different time zones, a Zoom-based poll showed that the meeting consisted of participants from all over the world, including, in order of decreasing number, Europe, the United States/Canada, and Asia. Most attendees responding to the poll were at the master’s/Ph.D. stage of their careers (48%), followed by university professors (28%), professionals in industry (17%), and finally, research assistants (7%).
Figure 2. Attendees of the Workshop on Modeling and Optimization for Active Devices.
Following each contribution, the polling features of Zoom were used to gather audience feedback on the presentation. The workshop participants were asked to place their votes for each presentation on a scale of 0–5 across the following criteria:
Overall, an average of approximately 23 valid votes was received for each presentation. The winning presentation was by Dr. N. Miller, titled “Nonlinear RF modeling of GaN HEMTs With Fermi Kinetics Transport and the ASM-HEMT Compact Model,” as shown in Figure 3.
Figure 3. The Best Presentation Award.
Contact Details
Justin King, Assistant Professor, Trinity College Dublin, Ireland. justin.king@tcd.ie
Gian Piero Gibiino, Assistant Professor, University of Bologna, gianpiero.gibiino@unibo.it
As the organizers of the inaugural YP Workshop on Modeling and Optimization for Active Devices, we are pleased to report that the event was a success. There was a clear interest among YPs for online workshops that provide opportunities for informal discussions and feedback on their work, as reflected in the positive feedback received from both participants and panelists. Considering this, we are hopeful for a second edition of the workshop and are open to suggestions, topics of interest, and proposals for presentations or participation. We encourage all YPs and researchers to engage with us by reaching out to our contact information (see “Contact Details”). We would like to extend our appreciation to the TC-2 Design Automation Committee and the seven panelists for their time and expertise.
[1] G. P. Gibiino et al., “TC-2 design automation committee—On the future of RF and microwave design automation,” IEEE Microw. Mag., vol. 23, no. 11, pp. 104–105, Nov. 2022, doi: 10.1109/MMM.2022.3196416.
[2] P. Beleniotis, F. Schnieder, S. Krause, S. Haque, and M. Rudolph, “An efficient drain-lag model for microwave GaN HEMTs based on ASM-HEMT,” Int. J. Microw. Wireless Technol., vol. 14, no. 2, pp. 134–142, Mar. 2022, doi: 10.1017/S1759078721001483.
[3] J. L. Gomes et al., “The impact of long-term memory effects on the linearizability of GaN HEMT-based power amplifiers,” IEEE Trans. Microw. Theory Techn., vol. 70, no. 2, pp. 1377–1390, Feb. 2022, doi: 10.1109/TMTT.2021.3132930.
[4] P. Cardinael et al., “Time dependence of RF losses in GaN-on-Si substrates,” IEEE Microw. Wireless Compon. Lett., vol. 32, no. 6, pp. 688–691, Jun. 2022, doi: 10.1109/LMWC.2022.3162028.
[5] N. C. Miller et al., “Experimentally validated gate-lag simulations of AlGaN/GaN HEMTs using fermi kinetics transport,” IEEE Trans. Electron Devices, vol. 70, no. 2, pp. 435–442, Feb. 2023, doi: 10.1109/TED.2022.3229291.
[6] L. Kouhalvandi, O. Ceylan, and S. Ozoguz, “Multi-objective efficiency and phase distortion optimizations for automated design of power amplifiers through deep neural networks,” in Proc. IEEE MTT-S Int. Microw. Symp. (IMS), Atlanta, GA, USA, 2021, pp. 233–236, doi: 10.1109/IMS19712.2021.9574937.
[7] M. Mengozzi, A. M. Angelotti, G. P. Gibiino, C. Florian, and A. Santarelli, “Joint dual-input digital predistortion of supply-modulated RF PA by surrogate-based multi-objective optimization,” IEEE Trans. Microw. Theory Techn., vol. 70, no. 1, pp. 35–49, Jan. 2022, doi: 10.1109/TMTT.2021.3121385.
[8] W. Li, G. Montoro, and P. L. Gilabert, “Digital linearization of wideband envelope tracking power amplifiers for mobile terminals,” IEEE Trans. Microw. Theory Techn., vol. 71, no. 1, pp. 48–58, Jan. 2023, doi: 10.1109/TMTT.2022.3217842.
Digital Object Identifier 10.1109/MMM.2023.3256821