A hybrid DGTD-FDTD method for RCS calculations

The Discontinuous Galerkin Time-Domain (DGTD) method is becoming a useful alternative to the classical Finite Difference Time-Domain (FDTD) method in order to overcome the inaccuracies of the latter when handling arbitrarily shaped geometries. DGTD takes advantage of a formulation very similar to that of the Finite Elements in Time Domain (FETD) with the same geometrical versatility. The main difference between both methods is that DGTD allows the solution to be discontinuous across contiguous elements, while FETD does not. This degree of freedom overcomes the fully implicit nature of FETD and significantly reduces computer requirements with a very low loss of accuracy. In this work, we first describe the fundamentals of DGTD. Then, we show some preliminary studies comparing the accuracy of DGTD and FETD in simple problems. Finally, we show a hybrid combination of FDTD and DGTD employing DGTD only to accurately model the geometric details of curved objects, while maintaining the simplicity of FDTD for the surrounding space. Radar Cross Section (RCS) results are used for validation.