SIGNAL-TO-NOISE RATIO IN AMPLIFIERS WITH AN INPUT CABLE

The amplifier noise level is analyzed when the detector and amplifier are connected by a cable. It is shown that the input cable of the prop osed amplifier has a characteristic length that stops affecting the no ise level when exceeded. The preamplifier noise level decreases if the time of the signal formation in the filter decreases. The noise level as a function of the gain of the preamplifier input stage is given. S ome recommendations on the increase of the signal-to-noise ratio for s imilar devices are formulated. The length of the applied input cables ranges from 1 to 100 m. The minimum duration of the preamplifier outpu t signals is 200 ns.