Study on a Receiver Circuit for Simultaneous Lightwave Information and Power Transfer

【Objective】The two functions of Energy Harvesting (EH) and Information Transmission (IT) are mutually restricted in the Simultaneous Lightwave Information and Power Transfer (SLIPT) system. In order to make the SLIPT system work more efficiently, it is necessary to regulate these two functions.【Methods】The article firstly tests the commonly used receiver circuit in SLIPT system to optimize the receiver. The receiver circuit designed in this article consists of three circuits: decoupling, energy harvesting and signal processing. The decoupling circuit consists of three branches, including Energy Harvesting Branch (EHB), Current Regulation Branch (CRB) and Information Transmission Branch (ITB), which is used to separate and regulate the output current of the optoelectronic converter. The EH circuit consists of three parts: boost circuit, energy management circuit and voltage stabilizing circuit, which is used for EH management and output. The signal processing circuit consists of a two-stage low-pass filtered non-inverting amplifier circuit and a threshold comparison circuit, which is used for signal filtering, amplifying and shaping. Finally, the receiving circuit is applied in a SLIPT system that uses Light-Emitting Diodes (LEDs) and Photovoltaic cells (PV) as optical/electrical conversion devices, and a microcontroller as the processor. The constraints and control methods between the two functions of EH and IT are summarized.【Results】Experiment results show that the SLIPT system based on the as-designed circuit can be controlled to work in the EH mode, IT mode, or information-energy simultaneous transmission mode. By adjusting the parameters of the receiving circuit, the PV output current distribution can be regulated, thereby controlling the power input to the EHB and the Signal-to-Interference Ratio (SIR) of the ITB. This enables efficient energy harvesting and stable information transmission. The corresponding energy storage power and communication rate can be balanced and regulated by the decoupling circuit.【Conclusion】The receiving circuit can operate without an external power supply and features maximum power point tracking, low power consumption, and adjustable operating modes.