Interception of EM Leakage Arising from the CRT of Computer

This research investigates the experiment to intercept and retrieve the electromagnetic (EM) leakage of video information arising from the cathode ray tube (CRT) of a computer. After the EM leakage signal is intercepted by an antenna, it is filtered, amplified and phase locked in the receiver. Then, the EM leakage signal is sampled via an A/D card and the digital data are sent to a software program. Further, the method to retrieve the available information from EM leakage is presented using techniques such as synchronization method, average filter, matched filter and wavelet transform etc. At last, the recovered Chinese characters from EM leakage are given as an image format.