A Planar Switching Integrated Quadrant Coil Antenna to form Widespread Switched Polarized H-field for Misalignment Resilient WPT System

Abstract

This paper presents a planar switching integrated quadrant coil antenna to mitigate lateral and angular misalignment problems in near-field wireless power transfer (WPT) applications. To allow a completely free receiver movement, both the misalignment problems are concurrently addressed by forming widespread distributions of switched polarized H-field in the receiver region. To achieve this, current circulations through the four quadrant coils composing the proposed antenna are judiciously controlled to form three orthogonal H-field components. For lateral misalignment mitigation, the widespread field distributions are obtained by using a field-forming approach for optimizing the antenna parameters. To produce the switched polarized H-field for angular misalignment mitigation, time-switching of the orthogonal H-field components is performed. This switching operation is realized by three DPDT switches inter-connecting the coils and integrated within the design for a cost-effective planar antenna solution. The fabricated prototype is measured and the experimental results are corroborated with the analysis. The results demonstrate potential of the proposed antenna to simultaneously mitigate both the misalignment problems for medium-range WPT of small devices which are allowed to freely rotate and displace such as medical implants, wireless endoscopy capsules and wearable devices etc.