“…The analysis of periodic metasurfaces using the homogenization theory became classical in electromagnetism [2,11,12,13,14], acoustics [15,16], elastodynamics [17,18] and water waves [19,20] and it results in effective jump (or "transition") conditions of the fields instead of their usual continuity relations (see Figure 1); the transition also involve effective parameters that may be known explicitly or given by the resolution of simple elementary static problems. In electromagnetism, the general structure of the jumps are given by the so-called Generalized Sheet Transition Conditions (GSTCs) and the effective parameters can be casted within tensors named surface susceptibility tensors.…”