% Author: Dr. Matthias Jung, DL9MJ
% Year: 2021
\begin{circuitikz}
    \draw[-Triangle](0.0,0.0) -- (5.0,0.0) node[anchor=north] () {$f$};
    \draw[-Triangle](0.0,0.0) -- (0.0,3.0) node[anchor=east] () {$U$} ;
    \draw [thick, rotate=180, xshift=-142.0*\getDarcImageFactor, yshift=-80*\getDarcImageFactor] plot [smooth, tension=1] coordinates {
        (0.80,0.1)
        (1.80,0.8)
        (2.50,2.7)
        (3.20,0.8)
        (4.20,0.1)
    };
    \draw [dashed] (2.5,0) -- (2.5,3);
\end{circuitikz}