WIRELESS CHARGING COIL ASSEMBLY

The disclosed technology provides an electronic device including a metal casing surrounding the electronic device. The metal casing has a first aperture including at least two sub-apertures connected by a channel. The metal casing also has a first surface on a charging target side of the metal casing and a second surface on a charging source side of the metal casing. The electronic device also includes a wireless charging coil located on the charging source side of the metal casing of the electronic device. The wireless charging coil is supplied with current from a power source. The current flowing through the wireless charging coil induces a surface current in the metal casing surrounding the electronic device. The current flowing through the wireless charging coil and the surface current cause a combined magnetic field.