Ground plane (GP) size drives total performance, for example: the optimal minimum GP length for loaded GPS PIFA is about 80-90mm, while the optimal minimum GP length for Loaded WIFI PIFA is about 50-60mm. Performance depends slightly on board materials, such as the loss tangent and dielectric constant, board shape and layer structure, as well as grounding schemes. An electrically long board is usually OK; it enables asymmetric placement of antenna without loss of efficiency. An electrically short board causes a drop in total radiated efficiency due to reduced radiation from board.