Filter Basics

Filtering is the oldest and most common type of signal processing, usually in the form of frequency selectivity or phase shaping, or both. Some examples of filter applications:

• Extracting a desired signal from other signals,
• Separating signals from noise,
• Anti-aliasing in analog-to-digital converters or smoothing in digital-to-analog converters,
• Phase equalization, and
• Limiting amplifier bandwidths for reducing noise, etc.