ABSTRACT This study presents a novel omnidirectional wireless power transfer (WPT) system based on a tri‐frequency orthogonal coil structure. The intensities of these magnetic fields can be independently controlled by adjusting the coil turn geometries. After optimization, the receiving coils selectively couple with designated magnetic fields without mutual interference. The system utilizes custom‐designed mutual inductances to maintain high efficiency regardless of the receiver's spatial position and orientation, thereby eliminating the need for active tuning or control circuitry. A square coil structure is chosen for the coupling coils due to its inherent stability and high mutual inductance. The transmitter assembly comprises three orthogonally arranged transmitting coils (Txs), while the receiver includes three mutually decoupled receiving coils (Rxs) along with a load coil (Lx) positioned on the same plane. Experimental validation confirms that the tri‐frequency channels enable interference‐free power transfer independent of the receiver's position and orientation. These results demonstrate that the proposed tri‐frequency coil design is well suited for various WPT applications.
Guo et al. (Mon,) studied this question.