% Author: Dr. Matthias Jung, DL9MJ
% Year: 2021
\begin{tikzpicture}
    \pgfplotsset{
        compat=1.10,
        width=\getDarcImageFactor * 16cm,
      standard/.style={
        axis x line=middle,
        axis y line=left,
        ticklabel style={fill=white},
        set layers=tick labels on top% use layers and choose the new layer set
      },
      layers/tick labels on top/.define layer set=% define the new layer set based on the standard one
      {axis background,axis grid,axis ticks,axis lines,main,%
        axis tick labels,% <- tick labels before main
        axis descriptions,axis foreground}
      {/pgfplots/layers/standard},
      clip=false
    }
  \begin{polaraxis}[
    /pgf/number format/.cd,
    use comma,
    domain=-180:180,
    ymin=-0.2,
    ymax=1.05,
    xmin=-45,
    xmax=45,
    axis line style={draw=none},
    ytick={0.4,0.5,0.6,0.7,0.8,0.9,1},
    yticklabels={,,},
    xtick={-40,-30,-20,-10,0,10,20,30,40},
    xticklabel={$\pgfmathprintnumber{\tick}^{\circ}$},
    xticklabel style={
      inner sep=6pt
    },
    xticklabels={$320^{\circ}$,$330^{\circ}$,$340^{\circ}$,$350^{\circ}$,$~~0^{\circ}$,$10^{\circ}$,$20^{\circ}$,$30^{\circ}$,$40^{\circ}$},
    ]
    
    \draw[very thick] plot[
      variable=\t,
      domain=0:360,
      smooth,samples=101
    ] 
    ({40*sin(\t)}:{129*pow(0.95*sin(\t/2),5)});
    
    \draw[very thick] plot[
      variable=\t,
      domain=0:360,
      smooth,samples=101
    ] 
    ({180+40*sin(\t)}:{12*pow(sin(\t/2),9)});
    
    \draw[anchor=base] (0,0) node[](origin){};
    
    \path[every node/.style={fill=white, below}]
      (0:40) node {0{,}4}
      (0:60) node {0{,}6}
      (0:80) node {0{,}8}
      (0:100) node {1};

    \path[every node/.style={fill=white, above}]
      (0:100) node {a}
      (0:85) node {b}
      (0:70) node {c}
      (0:50) node {d};

    \draw[thick, -Triangle] (180:20) -- (0:110);

    \path (0:110) node[below] {\footnotesize$\dfrac{E}{E_\mathrm{max}}$};
  \end{polaraxis}

  \draw[very thick]
    (origin) ++(0,-0.8) -- +(0, 1.6)
    (origin) ++(0.3,-0.7) -- +(0.0, 1.4)
    (origin) ++(0.6,-.6) -- +(0.0, 1.2)
    (origin) ++(0.9,-.5) -- +(0.0, 1)
    (origin) ++(1.2,-.4) -- +(0.0, 0.8)
    (origin) ++(1.5,-.3) -- +(0.0, 0.6);
\end{tikzpicture}