Near-field beamforming planar loop array for misaligned wireless power transfer

This paper presents a near-field beamforming loop array for misaligned wireless power transfer. The 1×4 loop array and the 4×4 loop array are introduced. By controlling each capacitance of array, the magnitude and phase of loop currents are optimized and, thus, it is possible to transfer power to a receiver placed orthogonally from the array. The comparison of power transfer efficiency between the array and the one large loop which has the same size as the array is performed. The one large loop has a higher efficiency than the loop array when a receiver is placed in parallel. However, when a receiver is placed orthogonally, the one large loop has zero efficiency while the loop array still has high efficiency. The experimental results agree with the theoretical results.