US Patent 10124687 Hybrid foreign object detection (FOD) loop array board

Techniques for detecting a presence of a metallic and/or a ferromagnetic object over a region for wirelessly transferring power to charge an electric vehicle are presented. An example apparatus includes one or more foreign object detection (FOD) loops arranged in an array over a charging area, at least a portion of the FOD loops being in a first configuration and at least a portion of the FOD loops being second configuration different than the first configuration based on a value indicative of an amount of magnetic coupling between the charging area and a respective one the FOD loops within a corresponding area of the array.