An Intrabody Power Transfer System With Continuous Maximum Resonant Power Tracking

In this letter, we present an intrabody-power-transfer (IBPT) system that delivers power greater than
$100~\mu \text{W}$
even across a 150-cm on-body distance. The proposed IBPT TX employs an FLL-based maximum-resonant-power-tracking (MRPT), which runs in the background to maximize the power delivered to the load (PDL). The proposed technique does not require any RX-to-TX back telemetry or searching phase, thus enabling uninterrupted power delivery. The PDL and power transfer efficiency are further improved by inducing parallel resonance at RX. Fabricated in a 180-nm BCD process, the proposed IBPT system achieves 136-
$\mathrm {\mu }\text{W}$
PDL at 1.8-V dc output with 8.83% end-to-end power efficiency.