Superimposition transmitter for protecting against reception/decoding of compromising PCs/monitor emissions emits signal restricted to compromising emission carrier spectral range

摘要

The device emits a superimposition signal restricted to the spectral region of the carrier of compromising emissions instead of broadband white noise. The monitor signals are received at the loop-connected monitor via electrical, inductive or capacitive coupling. The fundamental of the pixel clock frequency is detected as the basis of the superimposed protection signal.