Described herein are techniques related to near field communication and wireless power transfers. A portable device may include a modular antenna that offers consistent characteristics independent of integration environment. The modular antenna may include a continuous loop of coil antenna and a ferrite material that are encapsulated by a shield. The shield may form a “U” shape configuration to encapsulate the top layer coil antenna and the middle layer ferrite material in all three sides, which are defined by a bottom portion, an outer wall, and an inner wall. Furthermore, the shield may include an outer rim and an inner rim to maintain the same coil antenna characteristics in the modular antenna.