The following table lists software packages with their own article on Wikipedia that are nominal EM (electromagnetic) simulators;

Name License Windows Linux 3D GUI Convergence detector Mesher Algorithm Area of application NEC open source In some distributions manual MoM Antenna modeling, especially in Amateur Radio. Widely used as the basis for many GUI-based programs on many platforms. Version 2 is open source, but Versions 3 and 4 are commercially licensed. Momentum commercial equidistant MoM For passive planar elements development, integrated into Keysight EEsof Advanced Design System. Ansys HFSS commercial Automatic adaptive FEM, FDTD, PO, Hybrid FEBI, MoM, and Eigenmode expansion (EME). For antenna/filter/IC packages, Radome, RFIC, MMIC, Antenna Placement, Waveguide (radio frequency), EMI, Frequency selective surfaces (FSS), Electromagnetic metamaterials, Composite Material, RCS-Mono and Bi development. XFdtd commercial Automatic (project optimized) FDTD RF and microwave antennas, components, and systems, including mobile devices. MRI coils, radar, waveguides, SAR validation. AWR AxiemcommercialAutomatic, HybridMoMPCBs, multi-layer PCBs, LTCC, HTCC, on-chip passives, printed antennas. Integrated into Microwave Office. AWR AnalystcommercialAutomatic and adaptiveFEM3D structurers (including 3D antennas), waveguides, 3D filters, PCBs, multi-layer PCBs, LTCC, HTCC, on-chip Passives, printed antennas. Integrated into Microwave Office. JCMsuite commercial Automatic, error-controlled FEM Nano- and micro-photonic applications (light scattering, waveguide modes, optical resonances). QuickFieldcommercial and free editions Automatic or ManualFEMGeneral purpose for research, engineering and educational use, includes AC, DC and Transient Magnetics, Electrostatics, AC and DC Conduction, Transient Electrics, Heat Transfer and multiphysics COMSOL Multiphysicscommercial AutomaticFEM, MoM, BPM, ray tracingGeneral purpose FEKO commercial Automatic or manual; adaptive MoM, FEM FDTD MLFMM PO RL-GO UTD For antenna analysis, antenna placement, windscreen antennas, microstrip circuits, waveguide structures, radomes, EMI, cable coupling, FSS, metamaterials, periodic structures, RFID Elmer FEMopen source (GPL) manual, or can import other mesh formatsFEMGeneral purpose, includes 2D and 3D magnetics solvers, both static and harmonic. 3D solver is based on the Whitney AV formulation of Maxwell's equations. VSimEMCommercial Automatic, variable meshFDTD, PIC, finite volumeSimulating electromagnetics, and electrostatics in complex dielectric and metallic environments. Phased array antenna systems, radar equipment, and photonics. Meep open source (GPL) manual FDTD, FDFD Optics and photonics (nanophotonics, photonic crystals, plasmonics, silicon photonics, metamaterials)CST Studio SuitecommercialAutomatic, adaptiveFDTD/FIT, FEM, MLFMM, MoM, SBR, PICGeneral purpose – statics, low-frequency, microwaves and RF, terahertz, photonics, particle accelerators, electronics MPB open source (GPL) manual PWEM For band diagram and modal analysis of periodic structures (photonic crystals and metamaterials)

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