Plane wave excitation for frequency domain electromagnetic problems by means of impedance boundary condition

This paper presents how a plane wave excitation could be modeled in the context of the discrete geometric approach (DGA) by means of an impedance boundary condition, a capability that DGA was lacking. A methodology for the construction of an equivalent model of an anechoic wall is then presented as an application of the developed theory. The advantages of the resulting model are twofold: considering all the geometric details of the anechoic material requires more computational resources; in addition when an entire anechoic chamber is to be modeled, it is easier to deal with a flat wall rather than one covered with cones and ferrite tiles. The proposed equivalent model allows for a great simplification, while maintaining a good degree of accuracy.