4. Conclusion

In this article, we have successively seen a quadrupole representation in the form of a transfer matrix, a scattering matrix and a transmission matrix. The first and third representations are equivalent in that they allow us to present the waves reflected and transmitted by a device in electromagnetism and optics. Various examples of applications of these models have been given to make it easier for the reader to grasp these concepts. In the last part of this article, the case of surfaces and artificial materials was discussed, with examples of applications of these methods. Finally, the last example showed that it is relatively easy to obtain a complete mapping, as a function of incidence and frequency, of the electromagnetic parameters of these structures (reflection, transmission, input impedance, etc.).

Many manufacturers have implemented these methods to rapidly...