LaTeX Forum

\documentclass{scrreprt}
\usepackage{tikz}
\usepackage{pgfplotstable}
\usepackage[locale=DE]{siunitx}
\usepgfplotslibrary{units}
\pgfplotsset{compat=newest,width=.9\textwidth}

\begin{document}
\begin{figure}[h]
    \begin{tikzpicture}
        \pgfplotsset{set layers},
        \begin{axis}[
                width=0.78\textwidth,
                scale only axis,
                axis y line*=left,
                xmode=log,
                xmin=1, xmax=10000,
                ymin=0, ymax=40,
                xticklabels={\qty{1}{\mW}, \qty{10}{\mW}, \qty{100}{\mW}, \qty{1}{\W}, \qty{10}{\W}},
                log ticks with fixed point, x tick label style={/pgf/number format/1000 sep=\,},
                domain=1:10000,
                grid=both
            ]
            \addplot [very thick] {10*log10(x)};
        \end{axis}
        \begin{axis}[
                width=0.78\textwidth,
                scale only axis,
                xlabel={Watt [\unit{\W}]},
                ylabel={Dezibel [\unit{dB\m}]},
                axis y line*=left,
                axis x line*=none,
                xmode=log,
                xmin=1, xmax=10000,
                ymin=-40, ymax=0,
                xticklabels={\qty{100}{\nW}, \qty{1}{\uW}, \qty{10}{\uW}, \qty{100}{\uW}, \qty{1}{\mW}},
                log ticks with fixed point, x tick label style={/pgf/number format/1000 sep=\,},
                grid=both,
                axis line shift=10mm
            ]
        \end{axis}
    \end{tikzpicture}
    \caption{Leistung in Dezibelmeter [dBm]}
    \label{fig:leistung-in-dezibelmeter}
\end{figure}
\end{document}