A portable electronic device includes a circuit board and an antenna coil installed on the circuit board. The antenna coil includes a magnetic core and a coil wound at either side of an unwound portion. The winding direction of the coil is changed at either side of the unwound portion. When the length...http://www.google.de/patents/US20070247387?utm_source=gb-gplus-sharePatent US20070247387 - Portable Electronic Device
