Solving an electromagnetic problem can be handled in two phases. These are modelling the setup and carrying out the numeric evaluations. Throughout this study, the structure is modelled by Bezier surfaces and the antenna used is meshed with triangular patches. For the calculation part, the method of moments and physical optics (MoM-PO) hybrid method is implemented. While the calculations related with antenna are actualized by using MoM equations, the ones related with structure are obtained by using PO equations. Modified Ludwig's Algorithm is applied to calculate the current integral for the PO-region. This gives the ability to obtain successful results when the antenna is both close and far from the structure. Overall the stated modelling and calculation technique gives accurate results and saves time and memory in comparison with MoM.