Antenna Toolbox uses the method of moments (MoM) to compute port properties such as impedance, surface properties such as current and charge distribution, and field properties such as the near-field and far-field radiation pattern. You can visualize antenna geometry and analysis results in 2D and 3D.
Refer to the documentation on Method of Moments Solver for Metal and Dielectric Structures and Method of Moments Solver for Metal Structures for further details