A Circuit for Simultaneous Reception of Data and Power Using a Solar Cell

Abstract

This paper presents a circuit for simultaneous reception of optical power and data using a solar cell. The circuit employs a switched-inductor boost DC-DC converter for energy harvesting and a low-power thresholding receiver for data reception. The thresholding data receiver comprises a current-sense resistor that monitors the current output of the solar cell, an instrumentation amplifier, a band-pass filter and a comparator. A system-level analysis of an optical communication system employing the proposed circuit is presented along with a circuit-level analysis and implementation. As a proof-of-concept, the proposed circuit for simultaneous power and data reception is implemented using off-the-shelf components and tested using a custom-built test setup. Measurement results, including harvested power, electronic noise and bit error rate (BER), are reported for a GaAs solar cell and a red LED light source. Results show that 223 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> of power are harvested by the DC-DC converter at a distance of 32.5 cm and a radiated power of 9.3 mW. At a modulation depth of 50% and a transmission speed of 2.5 kbps, a BER of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.008\times 10^{-3}$ </tex-math></inline-formula> is achieved. Measurement results reveal that the proposed solution exhibits a trade-off between harvested power, transmission speed and BER.