Your observations are consistent with the scattering matrix of the branchline hybrid coupler;
<math> [S] = \frac{-1}{\sqrt{2}} \left[ \begin{array}{ccc}0 & j & 1 & 0 \\j & 0 & 0 & 1 \\1 & 0 & 0 & j \\0 & 1 & j & 0 \end{array} \right] </math>
== Exploring the Rat-Race Hybrid Coupler==