Design of a visible light communication transmitter for the evaluation of a wide range of modulation techniques

In this paper, we describe the development of a dedicated transmitter to be used in Visible Light Communication applications. The transmitter has a high power efficiency, so the communication functionality does not lead to significant power consumption. For this reason, a Trans-Conductance Amplifier (TCA) was designed making use of a class AB amplifier. The final design has an electrical bandwidth from 20 kHz until 25 MHz and is able to power LEDs with a driving current up to 700 mA. Results show that the bandwidth of the driver electronics is much larger than the bandwidth of the commonly used power LEDs that are designed for illumination purposes. Because the transmitter has the ability to implement different modulation techniques, as well digital as analogues in nature, it can be used in a wide range of applications depending on the needs of data rate and bandwidth.