Equivalent representation of multiport circuits by the use of scattering parameters is of fundamental importance, especially in the mi- crowave circuits area. However, in most cases, only a few pages of textbooks are devoted to this topic; based on the author’s experience, the students find it somehow difficult to understand the physical meaning of scattering pa- rameters (while they find other representations, like Z, Y, hybrid, or trans- mission parameters, easy to understand). For this reason, the contribution given by Sadiku (IEEE Trans. Educ., Vol. 46, no. 3, Aug. 2003, pp. 399–404) is very important. Furthermore, in Sadiku’s paper, three nontrivial exam- ples are reported, through which the students can gain understanding of this fundamental tool. In two of the three examples, some points are un- clear; this correspondence analyzes this lack of clarity.