Misalignment Resilient Anchor-Shaped Antennas in Near-Field Wireless Power Transfer Using Electric and Magnetic Coupling Modes

In this article, we propose a new antenna geometry for near-field magnetoelectric wireless power transfer (ME-WPT) application, where the antenna geometry is found to be resilient to misalignment between the receiving and the transmitting antennas. The proposed geometry is simple to fabricate and is planar, and therefore it can be easily integrated with various platforms suitable for wearable applications. The proposed structure is demonstrated to show improved WPT efficiency under different forms of misalignment between the transmitting and receiving antennas by the virtue of miniaturization and the fringing fields. Specifically, a central bar structure is added in the traditional loop antenna to provide dipole-like and miniaturized performance. Concurrently, a discontinuity in the loop is introduced to enable fringing fields beyond the aperture of the antenna. Investigations are conducted to conclude that a superiority in the performance is associated with these fringing fields. Design-optimization, simulation, and measurement investigations are conducted to estimate the WPT performance under various forms of misalignment. Notably, the proposed structure shows an increase as high as 65% in power transfer efficiency within the range of misalignment considered in this work.