plotting – Why are my polar grid lines limited by the maximum radial value?

I am wondering why the displayed polar grid lines are limited by the maximum plotted value (see minimal example below) – is it possible to show polar grid lines beyond the largest radial value?

Thanks and Best,
Tim

{ListPolarPlot({{(Pi)/4, 0.5}}, PlotRange -> {{-1, 1}, {-1, 1}}, 
  PolarGridLines -> {Range(0, 2 (Pi), 2 (Pi)/24), Range(0, 1, 0.1)}),
 ListPolarPlot({{(Pi)/4, 0.8}}, PlotRange -> {{-1, 1}, {-1, 1}}, 
  PolarGridLines -> {Range(0, 2 (Pi), 2 (Pi)/24), 
    Range(0, 1, 0.1)})}