Optimization of Edges in Short Square Pulses in Order to Reduce Shape Distortion

摘要

This paper addresses nanosecond square pulses transmitted by lossy transmission line on conventional printed circuit board. The pulse source is assumed to produce real square pulses with nonzero rise and fall times. Influence of parasitics on the shape is also taken into consideration. Shape distortion of transmitted pulses with duration from 0.1 ns to 10 ns is compared based on the measured transfer function of straight 25 cm long transmission line. For pulses with linear edges, distortion can be reduced using balanced relationship between the rise and fall times. Achievable reduction depends on the duration of the pulse; it is most effective for pulses of 2 ns to 5 ns. The results can be usable in signal processing where we know how much shape distortion can be tolerated.