Software and hardware for studying electromagnetic radiation generated by computing equipment in household electric network

Solution of the urgent scientific and technical problem in the field of information security – the problem of detecting electromagnetic radiation generated by computing aids – has been considered as part of studying radiation in the household electrical network. Developing an interface for coordination of a program-defined radio system with a household electrical network has been shown and a methodology for estimating the volume of the studied radiation in it has been proposed. Two matching units have been made: the first unit allocates a differential variable of the high-frequency component. The second unit distributes a cophased variable. To separate a low-frequency component and cut off the high low-frequency voltage, high-voltage ceramic capacitors were used. To protect the input from possible high-voltage pulses and noises, as well as half of the mains voltage, matching transformers on high-frequency ferrite were used. The components of the matching units are located inside the network plugs, and the SMA output slots are used to connect the receiver. A bandpass filter with a bandwidth of 50–500 MHz was developed as an additional mechanism for protecting the input circuits of the receiver. This range overlapped the necessary frequency range with a margin. Using the filter made it possible to additionally protect the SDR input of the receiver from high-voltage and broadband network interference, as well as to reduce the influence of the unwanted radiation on the receiver's ADC. The algorithm and methodology of registration, measurement and comparison of some quantitative parameters of electromagnetic radiation generated by computer technology are proposed. The revealed regularities indicate that weak signals of the studied radiation broadcast into the air are a potentially less energy-armed threat to the information security than electromagnetic emissions entering the electrical networks.