This paper describes several models which have been developed at Georgia Tech for the analysis of antennas, EMC, and biological effects. These models include algorithms based upon the plane-wave-spectrum scattering-matrix analysis, the geometrical theory of diffraction, and the method of moments. In addition, statistical models for antenna coupling, for out-of-band antenna performance, and for scattering by complex structures are discussed. In each case, the model results are compared with measured data to assess the accuracy of the modeling technique.