Efficient amplitude modulator and ripple canceller for visible light communication

Power loss is an important design factor for Visible Light Communication (VLC). Dissipating only a few percent of the illumination power can still result into a few watts of heat generation which requires additional provisions for cooling the modulator circuit. We show that a transistor in series with LED can be used in linear operation to apply amplitude modulation which only marginally sacrifices efficiency. Yet, this requires a novel active control loop. We report its performance and frequency response for VLC modulation. We show that the modulator also effectively cancels mains ripple. Based on our experimental experience, we also propose a model to quantify the power losses and verify these for pulse amplitude modulation

Efficient amplitude modulator and ripple canceller for visible light communication

Power loss is an important design factor for Visible Light Communication (VLC). Dissipating only a few percent of the illumination power can still result into a few watts of heat generation which requires additional provisions for cooling the modulator circuit. We show that a transistor in series with LED can be used in linear operation to apply amplitude modulation which only marginally sacrifices efficiency. Yet, this requires a novel active control loop. We report its performance and frequency response for VLC modulation. We show that the modulator also effectively cancels mains ripple. Based on our experimental experience, we also propose a model to quantify the power losses and verify these for pulse amplitude modulation