A planar aerial comprising a plurality of radiating plates (PR) connected by lines (LV, LH, LSV, LSH) having sufficient lengths for summing the signals at two points (H, V). On line H D G V the signal having a clockwise circularly polarised wave is present at D, and the signal having a counterclockwise...http://www.google.com/patents/US5233361?utm_source=gb-gplus-sharePatent US5233361 - Planar high-frequency aerial for circular polarization
