An implementation of the impedance-boundary CFIE using linear-linear basis functions and MLFMA

The results show that first-order LL linear basis functions may be successfully used to discretize the impedance boundary CFIE using an approach derived from that developed by Collino et al. The LL expansion yields lower errors in the calculated bistatic radar cross-section than that given by zero-order RWG basis functions with the same surface discretization mesh in all cases examined. However, LL basis functions require double the number of unknowns with the same mesh, and therefore a higher computation time.