4. Conclusion

In this article, we have first discussed the various methods for modeling random, more or less loaded composite materials, starting with the oldest (Maxwell-Garnett, Bruggeman) and ending with the most recent (Robin). The list of methods presented here is only partial, and we have endeavored to give their general principles. Specialized works exist, which are far more exhaustive. A number of them are referenced here.

Next, we presented the new concepts of 1D, 2D and 3D periodic artificial materials currently being developed, mainly in the microwave field. Photonic crystals, metamaterials, high-impedance surfaces and metasurfaces were presented. These materials are of great interest in many microwave applications, particularly in telecommunications, transport, security and defense.

We hope that this presentation has aroused the reader's interest...