Transmission Line Synthesis Approach to Extending the Bandwidth of LEDs for Visible Light Communication

This paper proposes, for the first time, a transmission line synthesis approach to extending the bandwidth of light- emitting diodes (LEDs) in the context of high capacity visible light communications links. As opposed to the more traditional pre-distortion, amplitude equalisation or driver circuitry based approaches, the extension in bandwidth is achieved by incorporating the LED diffusion capacitance into a pseudo-artificial transmission line (p-ATL) cell with significantly improved transmission and cut-off properties. With the proposed technique, we show the possibility of achieving close to 400% improvement in bandwidth with studies based on a verified LED equivalent model. It is envisaged that the proposed approach will enable bespoke driver circuits based on the individual characteristics of LEDs, while combination with existing bandwidth extension schemes can lead to further improvement.