AN IN-BODY TRANSMITTER AND ON-BODY RECEIVER USING BODY COUPLED COMMUNICATION

Abstract

This dissertation presents a TX/RX pair using I2O-BCC for ULP miniaturized implanted applications. To miniaturize the implanted device and reduce the power, we propose: 1) the galvanic coupling for low-loss transmission, 2) the IL-F2A conversion based demodulator to eliminate the need for accurate clock reference in TX, and 3) a system partitioning strategy through I2O-BCC.

We characterized the I2O-BCC characteristic through a specialized measurement setup. The I2O-BCC demonstrates low-loss communication within a wide band. The proposed IL-F2A based demodulator allows the FSK demodulation under significant TX frequency variation, enables the TX miniaturization by eliminating the need of off-chip clock reference. Integrated with an on-chip PMU, the operation hour of the implanted device is prolonged while using micro-battery.

The fabricated demodulator in RX can handle > ±10% frequency variations exhibited in the TX FSK signals. The packaged in-body TX is only 7×7×2 mm^3. The TX radio consumes 8.6 µW at 500 kb/s, while the on-body RX consumes 591.5 µW to recover the data and clock for the WBAN. The radio power are 8× lower than previous.