“…Interestingly, in the case of linear timeinvariant systems, these concepts are intimately related to the notion of Positive Real (PR) or of Strictly Positive Real (SPR) systems, which has been deeply explored not only in control but also in circuit theory, [2], [31], [32], [40]. In [18] a generalization of the Feedback Positive Real (FPR) design, introduced in [25], is discussed and subsequently extended to the setting of switching systems in [19]. The construction relies upon an observer-based state feedback control and on the circle criterion, thus increasing the realm of applicability of the solution proposed in [30], which yields a synthesis strategy in terms of a state feedback under the assumption that the underlying system is minimum-phase and possesses relative degree one.…”