Hybrid Transmission Line Matrix (TLM) and multipole expansion method for time-domain modeling of radiating structures

To model radiating electromagnetic structures a hybrid method is introduced, where within a spherical region complex electromagnetic structures are modeled with the TLM method. Outside the spherical region the field is expanded into spherical waves. At the boundaries of the spherical region the TLM solution is matched to the multipole expansion of the field in the outer region. This yields a potentially exact modeling of the radiating boundary conditions.