I. Introduction
Wireless Power Transfer (WPT) is gradually gaining acceptance by users and is regarded as a convenient and efficient technology for transferring power across relatively large airgaps. Due to the reliability, safety and environment inertness, etc., wireless power has become a promising energy transfer technology for numerous applications [1]–[5], such as biological implantation charging [2], portable devices charging [3], autonomous underwater vehicle (AUV) charging [4] and electric vehicles (EVs) stationary and dynamic charging [5]. Wireless power transfer technology has shown great potential in high power efficiency, unaffected by water, and maintenance free. With the advent of the 5G era, wireless charging can significantly improve users' experience for devices such as the Internet of Things (IoT). For example, an unmanned electric motorcycle, which can be widely used around campus and industrial zones, urgently requires dynamic WPT systems operating at kilowatts power level. However, charging with perfect alignment would negatively impact on the acceptance of the wireless charging technology. As a result, the development of a low-cost and reliable WPT circuit with high misalignment tolerance that can be used for both stationary and dynamic charging has become an urgent need in the design of practical wireless charging systems.