Adaptive Compensation Loop Control Method for Dynamic Range Wireless Power Transfer in Endoscopic Capsules Applications

摘要

In this paper, an adaptive compensation loop control method is presented for dynamic range wireless power transfer (WPT) based wireless endoscopic capsules (WEC) applications. Rather than a fixed external resistor feedback network utilized in the DC-DC converter with maximum power point control (MPPC) capability, an enhanced nMOSFET based adaptive compensation loop is introduced to extract maximum power transfer from the RF-DC rectifier within overall operational power range of the WEC system. Simulation in ADS and measurement among three rectifiers with an LDO, a fixed external resistor feedback network and an adaptive compensation loop control are performed respectively to achieve a steady 3.3V on a resistive load of 100 Omega, which validates that the proposed adaptive compensation loop control method realizes an extended dynamic power range with a lower limit of 21.5dBm to realize a minimum 100mW load DC power delivery for the IPT enabled WEC system.