An exact radiation boundary condition for the finite-element solution of electromagnetic scattering on an open domain

A major difficulty in applying the finite-element method (FEM) to electromagnetic scattering problems is the lack of a means to truncate the solution domain to lie within a finite boundary on which a condition is enforced, thus ensuring that the fields will obey the Sommerfeld radiation condition at distances asymptotically far from the object. An exact radiation boundary condition (RBC) that embodies the Sommerfeld radiation condition exactly is discussed. The price paid for exactness is that the exact RBC operator is global on the exterior boundary.>