RFID/NFC technology is widely used in various aspects of production and life, medical care, and so on. As the tag becomes smaller, the uncertainty in its orientation becomes more pronounced, especially for biomedical patches. To avoid the non-detection area for the tags and enhance the possibility of tag detection in RFID/NFC systems, a new type of 3D structure of the reader coil is designed and connected with R-C components in this paper to realize orthogonal currents in two perpendicular coils. Therefore, a rotating magnetic field is generated by tuning separately the 3D cube coils thanks to the mutual inductance auto-cancelling property of such structure.