Reflections and Signal Quality
Signal reflections are one of the most common and problematic phenomena affecting signal quality in high-speed digital systems. When a signal encounters an impedance discontinuity along its transmission path, a portion of the signal energy reflects back toward the source while the remainder continues forward. These reflections can cause voltage overshoots, undershoots, ringing, and intersymbol interference that degrade signal integrity and lead to timing errors or complete system failure.
Understanding the mechanisms that create reflections, how they propagate through transmission systems, and techniques for analyzing and mitigating them is essential for successful high-speed design. This section explores the theoretical foundations of reflections, practical analysis techniques, and design methodologies for maintaining signal quality in modern electronic systems.