Analog filters, composed of electrical components such as resistors, capacitors and op amps, have been used historically to filter continuous-time signals. In this lesson you will learn how a signal-processing system consisting of sampling, discrete-time filtering, and reconstruction is equivalent to an analog filter.
Sampling, discrete-time filtering, and reconstruction are often used in place of analog filters in many modern applications. The discrete-time approach is much more complex than an analog filter, but the relative cost is much less due to the inexpensive nature of digital electronics. Digital electronics also are much less sensitive to parameter drift, temperature, and other factors that affect the performance of analog filters.