From MHz to mmWaves: A Review of Application-Driven UK-Based Wireless Power Research

The deployment of the Internet of Things (IoT) has driven research in sustainable battery alternatives, including energy harvesting and wireless power solutions [1], [2], [3], [4], [5]. Wireless power transfer (WPT) and harvesting, ranging from near-field to short-range and km-range far-field solutions, have been extensively studied, with applications ranging from biomedical systems to pervasive ambient environmental monitoring. In this article, we review the recent contributions over the last decade, with a focus on R&D activities carried out in the United Kingdom. Key contributions in the field of WPT were demonstrated by U.K.-based teams, including the first large-scale ambient power surveys, through high-sensitivity and -efficiency millimeter-wave (mmWave) and simultaneous wireless information and power transfer (SWIPT) rectennas to near-field high-power systems and power electronics and applications in soft, wearable, and flexible electronics. Future research directions and challenges are also identified by a diverse range of active WPT research groups.