There is patch antenna image (i taken it from **broken link removed**)
Usually patch arrays have feeding line coming from one side. For example, all feeding lines can come from bottom side. But on this image we can see that feeding lines also come from top of patches, and have additional phase shift. What is the purpose of this phase shift? I thought it is additional 180 degree phase shift to make E-field vector look similar on patches with top and bottom field. But still unsure about that. Please comment