{ArcCosh[w/wc] + I*Pi/2, w \[GreaterSlantEqual] wc}} ] gain[w_] := 1/ E^Re[gam[w]]; Plot[ Table[ gain[w]^k, {k, {1, 2, 3, 4, 5, 10, 20}}], {w, 0, 2}, PlotRange...