Analysis of Electromagnetic Radiation of LCD Monitor with DisplayPort Interface

The present paper aims is to analyze the electromagnetic radiation (EMR) of a monitor with a DisplayPort interface and, based on the information obtained, to propose methods for detecting spectral components of informative interfaces and determining the effective frequency band. An automated workplace with a single monitor and, accordingly, a specification for a single-threaded video signal transmission mode is considered as the computer processed information under study. When conducting a research of the interface architecture components affecting the distribution of EMR energy in the spectrum, it was determined that the noise immunity of the main channel lines depends on the configuration settings of the DisplayPort. This dependence makes it possible to change the configuration by software and thus significantly affect the quality of testing. An experiment was performed, the results of which showed that the power distribution of the EMR depends on the applied modulation transformation. Based on the results of the experiment, a method for detecting spectral components for LVDS, RSDS and DisplayPort interfaces using an R&S FSW 13 spectrum analyzer and an anechoic chamber is proposed. Based on the analysis of the spectrum envelope and the specification of the DisplayPort interface, it was determined that the reason for the continuous power distribution of the signals of the interfaces is the use of SSFM for the DisplayPort interface and linear frequency modulation for the LVDS and RSDS interfaces. Based on the results of the research, methods for determining their effective signal bandwidth are proposed.