Spectral Leakage and Windowing Effects in Real DSP Measurements
Introduction FFT-based spectral analysis assumes signals are periodic within observation windows. Real signals rarely satisfy this assumption. The result is spectral leakage — energy spreading across frequency bins. Window functions reduce leakage but introduce their own distortions. This article explains how leakage and windowing effects shape real DSP measurements and why engineers must account for them. Why Leakage Occurs When signal periods do not align with FFT window boundaries: discontinuities occur at segment edges frequency content spreads across bins This produces: ...