Extracting maximum efficiency of wireless power transfer in endoscopic capsule applications

In this paper, a maximum efficiency extracting technique is presented for endoscopic capsule's Wireless Power Transfer (WPT). Instead of conventional regulators, a DC-DC Bulk LTC3129-1 with Maximum Power Point Control (MPPC) capability is adopted to boost the power conversion efficiency of the WPT receiver (including RF-DC rectifier and DC-DC Converter) up to 60%. Measurements validate that DC-DC Bulk LTC3129-1 outperforms the LDO over the operational power ranges from 22.5dBm to 25dBm. The presented WPT receiver system with DC-DC Bulk is practical for the maximum efficiency extraction of WPT in endoscopic capsule applications.