A wireless electronic device is disclosed that includes one or more ground planes and an antenna electrically coupled to the one or more ground planes. The antenna is positioned adjacent to a portion of the one or more ground planes. The wireless electronic device includes a material placed in a position and having a dielectric constant selected to increase an effective electrical size of the one or more ground planes relative to the effective electrical size of the one or more ground planes without the material. Other wireless electronic devices and methods for forming the same are also disclosed.