ESTIMATING THE REDUCTION OF RADIATED EMISSIONS FROM TFT-LCD PANEL USING NETWORK ANALYZER WITH A BULK CURRENT INJECTION PROBE

A network analyzer with a bulk current injection (BCI) probe is proposed to measure the common-mode conversion coefficient for DC supply loops on a driver PCB of thin film transistor-liquid crystal display (TFT-LCD) panel. The proposed technique is used to predict the common-mode radiated emission caused by the DC supply loops, which highly correlates with the radiated emission measurements obtained for the TFT-LCD panel in a fully anechoic chamber (FAC). The proposed technique is also successful to estimate the reduction of a specific peak in the radiated emission spectrum by shielding the DC supply loops on a driver PCB of TFT-LCD panel. Electromagnetic simulation and equivalent-circuit modeling approaches are developed to confirm the common-mode radiation mechanism in this study.