Investigation of Hardware Equalizer Based on a Bridged-T Network for High-Speed VLC

This paper comprehensively investigates a bridged-T pre-equalizer circuit (BTEC) designed for a high-speed visible light communication (VLC) system. The circuit is intended to mitigate the bandwidth limitation of light-emitting diodes (LEDs) in the VLC system. We integrate the advanced design system and MATLAB to analyze the BTEC using scattering parameters
$S11, S12, S21$
, and
$S22$
. The BTEC is fabricated using standard flame-retardant type-4 printed circuit boards (PCBs) with a 4.5×1.5 mm
²
size. The measurement shows that the pre-equalizer centre frequency is similar at 654 MHz for all test sets but with varying dynamic magnitude gains in the range of -9.49 to -33.4 dB. The designed BTEC demonstrates that the bandwidth of LED can be extended to provide a solid foundation for future investigations into this area.