High-Fidelity Near-Field mmWave MIMO Radar Simulation via Polarized Path Tracing

Hofmann N, Wirth V, Gutsche F, Ullmann I, Weyrich T, Vossiek M, Stamminger M (2026)

Publication Type: Journal article

Publication year: 2026

Journal

IEEE Journal of Microwaves IEEE

Original Authors: Nikolai Hofmann, Vanessa Wirth, Florian Gutsche, Ingrid Ullmann, Tim Weyrich, Martin Vossiek, Marc Stamminger

Pages Range: 1-16

DOI: 10.1109/JMW.2026.3719794

Abstract

Accurate simulation of near-field millimeter-wave (mmWave) multiple-input multiple-output (MIMO) radars is essential for developing and validating high-resolution imaging systems, yet remains challenging due to large virtual apertures, multi-path propagation, and polarization effects that invalidate conventional far-field assumptions. We present a Shooting and Bouncing Rays (SBR) simulation framework that formulates radar signal transport analogously to physically based rendering, replacing far-field radar cross section approximations with spatially varying bidirectional reflectance distribution functions (BRDFs) to accurately model near-field scattering. Path tracing enables tractable multi-bounce simulation, while importance sampling over antenna gain patterns and BRDFs, combined with next-event estimation for TX–RX connections, significantly improves convergence. Polarization is incorporated via a three-dimensional Jones vector formulation, enabling correct modeling of polarization-dependent scattering across multi-bounce ray paths. Quantitative and qualitative evaluation against real measurements from a 72–82 GHz high-resolution MIMO imaging radar demonstrates faithful reproduction of real radar returns, including challenging corner reflector scenes dominated by multi-bounce returns. Ablation studies confirm that multi-path modeling, polarization, and BRDF importance sampling are each essential for high-fidelity radar simulation.

Authors with CRIS profile

Nikolai Hofmann Chair of Visual Computing (LGDV) Vanessa Wirth Chair of Visual Computing (LGDV) Florian Gutsche Chair of Visual Computing (LGDV) Ingrid Ullmann Department Elektrotechnik-Elektronik-Informationstechnik (EEI) Tim Weyrich Lehrstuhl für Informatik 15 (Digital Reality) Martin Vossiek Lehrstuhl für Hochfrequenztechnik (LHFT) Marc Stamminger Chair of Visual Computing (LGDV)

How to cite

APA:

Hofmann, N., Wirth, V., Gutsche, F., Ullmann, I., Weyrich, T., Vossiek, M., & Stamminger, M. (2026). High-Fidelity Near-Field mmWave MIMO Radar Simulation via Polarized Path Tracing. IEEE Journal of Microwaves, 1-16. https://doi.org/10.1109/JMW.2026.3719794

MLA:

Hofmann, Nikolai, et al. "High-Fidelity Near-Field mmWave MIMO Radar Simulation via Polarized Path Tracing." IEEE Journal of Microwaves (2026): 1-16.

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