An Intra-Body Power Transfer System with>1-mW Power Delivered to the Load and 3.3-V DC Output at 160-cm of on-Body Distance

Hyungjoo Cho, Ji Hoon Suh, Chul Kim, Sohmyung Ha, Minkyu Je

Research output: Contribution to journalArticlepeer-review


This paper presents an intra-body power transfer (IBPT) system that can deliver power greater than 1 mW across an on-body distance of 160 cm. A system simulation model is built for the characterization of the channel and optimization of the power transfer. Our system analysis and experimental validation demonstrate that 1 MHz is an optimal carrier frequency for IBPT in terms of power delivered to the load (PDL) and power efficiency (PE). Prototype TX and RX boards were built, and an IC was fabricated in a 180-nm CMOS process for the RX. The proposed RX IC consists of a voltage doubler (VD) and a charge pump (CP) to obtain a sufficiently high voltage conversion ratio (VCR). Among various rectifier topologies, the VD is the optimal topology for the power receiver front-end because the parasitic ground coupling capacitances, which inevitably exist in the IBPT system, act as an inherent input-coupling capacitance for the VD. The implemented VD utilizes a dynamic V{TH} compensation (DVC) for its diode components. Compared to the conventional static V{TH} compensation (SVC), DVC in the VD reduces the reverse leakage current of the diode, thus maximizing the power conversion efficiency (PCE) and VCR. In addition, the PDL is enhanced by inserting an inductor on the TX board. It reduces the backward-path impedance without increasing the RX volume, boosting the PDL by up to 9.9 times compared to the PDL without the inductor insertion. The proposed IBPT system delivers up to 178.8 \muW of power at 11.7% of maximum power efficiency with 3.3-V DC output voltage and even 1.385 mW of power with the inductor insertion, supporting various biomedical wearable sensors, such as ECG sensor modules.

Original languageEnglish (US)
Pages (from-to)852-866
Number of pages15
JournalIEEE Transactions on Biomedical Circuits and Systems
Issue number5
StatePublished - Oct 1 2022


  • AC-DC converter
  • Body-area network (BAN)
  • body-channel communication (BCC)
  • body-channel model
  • energy harvesting (EH)
  • intra-body power transfer (IBPT)
  • power delivered to the load (PDL)
  • power efficiency (PE)
  • voltage doubler
  • wearable devices
  • wireless power transfer (WPT)

ASJC Scopus subject areas

  • Biomedical Engineering
  • Electrical and Electronic Engineering


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