% Author: Dr. Matthias Jung, DL9MJ
% Year: 2026
\begin{circuitikz}
    \draw[-Triangle](0,0) -- (5.0,0.0) 
        node[anchor=north east] () {$f$};
    \draw[-Triangle](0.0,0.0) -- (0.0,3.0)
        node[rotate=90, anchor=south east] () {$U_\text{A}$~~bzw. Verstärkung};

    \draw[rounded corners=3mm, thick, black, DARCblue] 
    (0,2.5) -- ++(3.7,0) -- ++(0.6,-2.5) -- ++(0.6,0);

    \draw [dashed, gray] (3.875,0) node[anchor=north](){$f_\text{g}$} -- ++(0,3) node[near start, anchor=north, rotate=-90] () {Grenzfrequenz};
\end{circuitikz}