% Author: Dr. Matthias Jung, DL9MJ
% Year: 2020
\begin{tikzpicture}
    \pgfplotsset{samples=200}
    \begin{axis}[
        axis on top,
        axis lines=middle,
        height=6cm,
        scale only axis,
        width=\linewidth*\getDarcImageFactor,
        ticks=none,
        axis line style={-Triangle},
        xticklabel style={/pgf/number format/.cd,fixed,precision=1,use comma,fixed,fixed zerofill},
        xmin =  0,
        ymin = -2.5,
        xmax =  9,
        ymax =  3,
        domain = 0:6.75,
        thick,
        smooth,
        no markers]
        \addplot+[name path=A,ultra thick, black] { 0.75*sin(deg(x)-180)+1.5};
        \addplot+[name path=B,ultra thick, black] {-0.75*sin(deg(x)-180)-1.5};
        \addplot[gray] fill between[of=A and B];

        \draw[dashed] (axis cs: -0.25,1.50) -- (axis cs: 8,1.5);
        \draw[dashed] (axis cs: 3*0.5*3.14,2.25) -- (axis cs: 8,2.25);

        % Bemaßung zeichnen:
        \draw(axis cs: 3*0.5*3.14,0) coordinate(start);
        \draw(axis cs: 3*0.5*3.14,1.5) coordinate(end);
        \draw($(start)!0.5!(end)$) coordinate(middle);
        \node[anchor=west] (text) at (middle) {$\hat U_\mathrm{T}$};
        \draw[Triangle-] (start) -- (middle);
        \draw[Triangle-] (end) -- (middle);
        %
        \draw(axis cs: 6.5,1.5) coordinate(start);
        \draw(axis cs: 6.5,2.25) coordinate(end);
        \draw($(start)!0.5!(end)$) coordinate(middle);
        \node[anchor=west] (text) at (middle) {$\hat U_\mathrm{mod}$};
        \draw[Triangle-] (start) -- (middle);
        \draw[Triangle-] (end) -- (middle);
    \end{axis}
\end{tikzpicture}