Here's a paper that shows reflections (Fig. 3, "S11") and insertion loss (Fig. 4, "S12") on coplanar waveguides, when using a sharp 90° bend, a 90° bend with a champfer and the case where the bend is replaced by two successive 45° turns ("final design").
The frequency scale spans 10..90 GHz.
http://tentzeris.ece.gatech.edu/ECTC09_Rida.pdf