A Combined Subdomain Method of Moments and Asymptotic Waveform Evaluation for Fast Wideband Bistatic Radar Cross Section Prediction

A hybrid scheme combining subdomain method of moment (SMoM) and asymptotic waveform evaluation (AWE) technique is presented for fast wideband bistatic radar cross section (BCS) prediction of arbitrary shaped 3-D targets. To deal with the multiscale problems, the target can be divided into several subdomains, and each subdomain can be properly meshed and handled. To achieve fast frequency sweeping, the initial moments of Taylor coefficients on each subdomain are solved by the standard AWE, and then, the new moments can be updated by expanding the complex excitation vectors into a Taylor series since the couplings among these subdomains should be considered. Moreover, the moments of Taylor coefficients on the virtual surfaces are also needed to be updated by enforcing the boundary conditions on the interfaces between adjacent subdomains to ensure the current continuity. To obtain a better bandwidth, the Padé approximation is applied in the proposed SMoM-AWE approach. Numerical results show that the SMoM-AWE approach exhibits excellent performances in terms of computational efficiency compared with the traditional method of moment (MoM) and SMoM.