The Applied Computational Electromagnetics – Signal Power Integrity (ACEM-SPI) Group

Research Statement:

• Professor Zadehgol’s research interests include theoretical, applied, and computational electromagnetics, with a special focus on the advancement of computational algorithms and methods for the efficient (accurate, fast, and stable) modeling of arbitrary structures (media and geometries) including electrical devices, circuits, systems, and networks. In parallel, his research pursues the advancement of modeling and simulation methods in signal/power integrity (SPI) and electromagnetic compatibility (EMC) across the frequency spectrum, from optical (100s of THz), to µ-waves and mm-waves (100s of MHz to 100s of GHz), to quasi-statics (10s of Hz). His past research includes development of methodologies for modeling of disparately multi-scaled and stochastic systems, with emphasis on: computational electromagnetics (CEM); model-order-reduction (MOR); system identification, passivity/causality/stability analysis, and autonomous equivalent circuit synthesis; and modeling aided by artificial intelligence (AI) and machine learning (ML) methods. A recent interest of his group has been pursuing the advancement of modeling around quantum science and engineering, including quantum electrodynamics, quantum computing, and photonics.

Research areas:

• Electromagnetics, optics, and opto-electronics

• Microelectronics

• Signals and Systems

Research Interests:

• Theoretical, applied, and computational electromagnetics (FDTD, FEM) [1-3].

•  Algorithms and methods for modeling disparately multi-scaled and stochastic systems (e.g., stochastic collocation) [4, 5].

• Model order reduction (SAPOR, ENOR) [6, 7].

• Machine Learning and Neural Network modeling (Deep Neural Networks) [8-11].

• System identification (Vector Fitting, PRESS) [12, 13].

• Signal & power integrity (including passivity, causality, and stability) modeling and simulation of high-performance (high-speed, ultra-thin, low-power/energy, and dense) microelectronics (chip + package + system) [14-17].

• Parallelization (GPU, CPU) [18, 19].

•  Electromagnetic scattering, remote sensing, and imaging.

• Thermo-electric modeling and simulation, and thermal sensing.

• Modeling and simulation of multi-physics phenomena.

Selected past projects, by frequency spectrum:

•  100s of THz: Optical nano-scale dielectric waveguides with structural uncertainty [19-27].

•  100s of MHz to 100s of GHz: (1) µ-electronic packages [18, 21, 28, 29], (2) µ-wave and mm-wave transmission lines [8, 30], (3) EM band-gap structures [1, 31], and (4) Antennas [32-34].

• 10s of Hz: Power system reactors [35, 36].

Future research directions:

• We are currently expanding our capabilities to tackle research projects on Quantum science and engineering, e.g., Quantum Electrodynamics, Quantum Computing, and Photonics.

References

[1]     A. Zadehgol, "Probabilistic Finite-Difference Time-Domain Simulations Using Stochastic Electromagnetic Macro-Models," Ph.D., Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Illinois, 2011. [Online]. Available: http://hdl.handle.net/2142/29732

[2]     A. Zadehgol, A. C. Cangellaris, and P. L. Chapman, "A model for the quantitative electromagnetic analysis of an infinitely long solenoid with a laminated core," International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, vol. 24, no. 3, pp. 244-256, 2011.

[3]     A. Zadehgol and A. C. Cangellaris, "Isotropic Spatial Filters for Suppression of Spurious Noise Waves in Sub-Gridded FDTD Simulation," IEEE T Antenn Propag, vol. 59, no. 9, pp. 3272-3279, 2011.

[4]     A. Zadehgol, "Stochastic Reduced-Order Electromagnetic Macromodels in FDTD," IEEE T Antenn Propag, vol. 64, no. 8, pp. 3496-3508, 2016.

[5]     A. Zadehgol, "Complex s-Plane Modeling and 2D Characterization of the Stochastic Scattering Loss in Symmetric Dielectric Slab Waveguides Exhibiting Ergodic Surface-Roughness with an Exponential Autocorrelation Function," IEEE Access, pp. 1-1, 2021, doi: 10.1109/access.2021.3092635.

[6]     A. Zadehgol, "Deterministic Reduced-Order Macromodels for Computing the Broadband Radiation-Field Pattern of Antenna Arrays in FDTD," IEEE T Antenn Propag, vol. 64, no. 6, pp. 2418-2430, 2016.

[7]     A. Zadehgol, "An Impedance Transfer Function Formulation for Reduced-Order Macromodels of Subgridded Regions in FDTD," IEEE T Antenn Propag, vol. 65, no. 1, pp. 401-404, 2017.

[8]     S. Newberry and A. Zadehgol, "A Deep Neural Network Modeling Methodology for Extraction of RLGC Parameters in µ-wave and mm-wave Transmission Lines," presented at the 2022 IEEE International Symposium on Electromagnetic Compatibility & Signal/Power Integrity (EMC-SI), 2022.

[9]     B. Guiana, "Class project for ECE 504 entitled Machine Learning for Electromagnetics", taught by Prof. Zadehgol at University of Idaho, Moscow, ID, in Spring 2022," ed, 2022.

[10]   B. Guiana and A. Zadehgol, "Machine Learning for Rectangular Waveguide Mode Identification, Using 2D Modal Field Patterns," presented at the 2023 United States National Committee of URSI National Radio Science Meeting (USNC-URSINRSM), Boulder, CO, 2023.

[11]   R. Choupanzadeh and A. Zadehgol, "A Deep Neural Network Modeling Methodology for Efficient EMC Assessment of Shielding Enclosures using MECA-Generated RCS Training Data," IEEE Transactions on Electromagnetic Compatibility, 2023.

[12]   V. Avula and A. Zadehgol, "Pole Residue Equivalent System Solver (PRESS)," presented at the 2016 IEEE 20th Workshop on Signal and Power Integrity (SPI), 2016.

[13]   V. Avula and A. Zadehgol, "Coarse-to-fine malleable Pole/Residue Equivalent System Solver (COMPRESS)," in 2016 IEEE Electrical Design of Advanced Packaging and Systems (EDAPS), 2016, pp. 91-93.

[14]   A. Zadehgol, "A semi-analytic and cellular approach to rational system characterization through equivalent circuits," International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, vol. 29, no. 4, pp. 637-652, 2016.

[15]   R. Choupanzadeh and A. Zadehgol, "Stability, Causality, and Passivity Analysis of Canonical Equivalent Circuits of Improper Rational Transfer Functions with Real Poles and Residues," IEEE Access, vol. 8, pp. 125149-125162, 2020, doi: 10.1109/ACCESS.2020.3007854.

[16]   A. Zadehgol, "Passivity Considerations for Sub-Gridded FDTD with Discrete Complex Wave Impedance," 2016 International Symposium on Electromagnetic Compatibility - EMC Europe, pp. 72-74, 2016.

[17]   R. Choupanzadeh and A. Zadehgol, "Stability, Causality, and Passivity of Canonical Equivalent Circuits for Improper Rational Transfer Functions, Part II: with Complex-Conjugate Poles and Residues," IEEE Access, pp. 1-1, 2023, doi: 10.1109/ACCESS.2023.3321631.

[18]   V. Avula, P. Mahanta, and A. Zadehgol, "Parallel, Optimized, Error Maxima-Agnostic, Pole Residue Equivalent System Solver," IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 8, no. 1, pp. 5-12, 2018.

[19]   B. Guiana. "Optical Interconnect Designer Tool (OIDT)." https://github.com/bmguiana/OIDT (accessed September 15, 2022.

[20]   A. Zadehgol, "SHF: SMALL: A Novel Algorithm for Automated Synthesis of Passive, Causal, and Stable Models for Optical Interconnects; Award #1816542," ed: National Science Foundation (NSF), 2018-2021, extended to 09/2022.

[21]   A. Zadehgol, "Signal and Power Integrity Modeling of Microelectronic Packages," ed: Micron Technology Inc., 2015-2018.

[22]   B. Guiana and A. Zadehgol, "Characterizing THz Scattering Loss in Nano-Scale SOI Waveguides Exhibiting Stochastic Surface Roughness with Exponential Autocorrelation," Electronics, vol. 11, no. 3, 2022, doi: 10.3390/electronics11030307.

[23]   B. Guiana and A. Zadehgol, "S-Parameter Extraction Methodology in FDTD for Nano-Scale Optical Interconnects," presented at the 15th International Conference on Advanced Technologies, Systems and Services in Telecommunications (TELSIKS), Nis, Serbia, 2021.

[24]   B. Guiana and A. Zadehgol, "FDTD Simulation of Stochastic Scattering Loss Due to Surface Roughness in Optical Interconnects," presented at the 2022 United States National Committee of URSI National Radio Science Meeting (USNC-URSINRSM), Boulder, CO, 2022.

[25]   B. Guiana and A. Zadehgol, "Stochastic FDTD Modeling of Propagation Loss due to Random Surface Roughness in Sidewalls of Optical Interconnects," in 2021 United States National Committee of URSI National Radio Science Meeting (USNC-URSINRSM), 2021, pp. 266-267, doi: 10.23919/USNC-URSINRSM51531.2021.9336433.

[26]   B. Guiana and A. Zadehgol, "Width Confinement in 3D Dielectric Waveguides and Comparison to 2D Analytical Models," presented at the 2023 United States National Committee of URSI National Radio Science Meeting (USNC-URSINRSM), Boulder, CO, 2023.

[27]   R. Choupanzadeh. "S-parameter to Reduced-Order Passivity-Enforced Equivalent Circuit (SROPEE)." GitHub. https://github.com/RasulChoupanzadeh/SROPEE (accessed October 10, 2023.

[28]   A. Zadehgol, "Analytical Model of 3-D Helical Solenoids for Efficient Computation of Dynamic EM Fields, Complex Inductance, and Radiation Resistance," IEEE Transactions on Electromagnetic Compatibility, pp. 1-11, 2023, doi: 10.1109/TEMC.2023.3298886.

[29]   V. Avula, A. Zadehgol, A. El-Mansouri, F. Badrieh, and B. Keeth, "A novel iterative method for approximating frequency response with equivalent pole/residues," in 2016 IEEE International Symposium on Electromagnetic Compatibility (EMC), 2016, pp. 806-811, doi: 10.1109/ISEMC.2016.7571753.

[30]   A. Zadehgol and H. J. Maramis, "Apparatus, system, and method for high frequency signal distribution; Patent No. US 7,106,147 B1," USA, 2006. [Online]. Available: https://patents.google.com/patent/US7106147B1/

[31]   A. Zadehgol, "Reduced-order stochastic electromagnetic macro-Models for uncertainty characterization of 3-D band-gap structures, in FDTD," in 2017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2017, pp. 2421-2425.

[32]   J. Ziegler and A. Zadehgol, "Electrically small PCB stack hemispherical helix antenna with air core," in 2017 International Workshopon Antenna Technology: Small Antennas, Innovative Structures, and Applications (iWAT), 2017, pp. 355-358.

[33]   A. J. Khalilabadi and A. Zadehgol, "Multiband antenna for wireless applications including GSM/UMTS/LTE and 5G bands," in 2018 International Applied Computational Electromagnetics Society Symposium (ACES), 2018, pp. 1-2, doi: 10.23919/ROPACES.2018.8364167.

[34]   J. Ziegler and A. Zadehgol, "Stacked Printed Circuit Board Implementations of Three Dimensional Antennas; Patent No. US 10,347,976 B2," USA, 2019. [Online]. Available: https://patents.google.com/patent/US10347976B2/

[35]   A. Zadehgol, "A Parametric Integral Formulation to Approximate the Magneto Quasi-Static Fields of 3-D Cylindrical Solenoids With Helical Winding," IEEE T Magn, vol. 58, no. 7, pp. 1-13, 2022, doi: 10.1109/tmag.2022.3176061.

[36]   A. Zadehgol, H. Lei, and B. K. Johnson, "A Methodology for Remote Sensing Inter-Turn Fault Events in Power System Air-Core Reactors, via Simulation of Magneto Quasi-Static Fields in 2D FDTD," IEEE Access, pp. 1-1, 2020, doi: 10.1109/access.2020.3024927.

Applied Computational Electromagnetics (ACEM):

ACEM Applications:

ACEM has many important applications, including Signal and Power Integrity (SPI) for microelectronics. SPI sits at the intersection of three main areas: electromagnetics, microelectronics, and signals & systems. The below diagram attempts to show some of the applications of ACEM.