Selection of the surface impedance boundary conditions for a given problem

It is well-known that the surface impedance boundary conditions (SDBCs) are classified by their order of approximation. In the present paper, universal relationships between characteristic values of the problem are proposed considering the order of approximation so that the SIBCs, best suited to a given problem, can be easily selected. The methodology is applicable to the time-frequency domain linear and nonlinear SIBCs. Numerical examples are included to illustrate the methodology.