% Author: Dr. Matthias Jung, DL9MJ
% Year: 2021
\begin{circuitikz}
    %\tikzstyle{help lines}=[blue!50];
    %\draw[style=help lines] (-2,-2) grid (18,8);
    \draw (0,0) coordinate(start)
        to [TL, name={foo}, bipoles/tline/width=2, o-] ++(-3.5,0)
        |- (foo.top right)
        to [short,-*] ++ (0,0);
    \draw[dashed] (foo.west) -- ++(foo.east); 
    \draw(start) to [open, name={bar}] ++(0,-1) coordinate(end);
    \draw(end)
        node[ocirc]{}
        -| (foo.top left)
        to [short,-*] ++ (0,0);
    \draw(bar) node[](){a};
    \draw(foo.north) node [anchor=north]{$Z=\qty{50}{\ohm}$};
\end{circuitikz}