3. Wireless Energy Management Integrated Circuits

This chapter delves into a comprehensive range of rectification architectures and adaptive energy reception techniques, offering insight into both fundamental and state-of-the-art solutions. First, this chapter begins with passive rectifiers, introducing conventional diode-bridge and cross-coupled topologies, and progresses toward enhanced efficiency through threshold voltage-reduction and active diode implementations. Building upon this, we explore active rectifiers that leverage high-speed comparators and offset-controlled feedback for precision switching, significantly improving power conversion efficiency (PCE) at high operating frequencies. The concept of active voltage doublers and multipliers further extends voltage conversion capabilities while addressing startup and timing challenges. To support modern system-on-chip (SoC) applications, we present single- and multi-output resonant regulating rectifiers (R³), including dual- and three-output designs that efficiently manage power distribution across varying voltage domains. Adaptive rectifier structures, including reconfigurable and optimal-tracking converters, are also covered, demonstrating real-time adjustment to dynamic load and link conditions. Finally, this chapter introduces resonant-mode energy receivers, including time-interleaved and non-residual designs, which enable efficient long-range power delivery by capturing and transferring maximum energy without losses. Together, this chapter provides a foundation and roadmap for designing next-generation AC-DC converters and energy receivers in WPT systems, emphasizing efficiency, adaptability, and integration.