Digital Filter

What Does Digital Filter Mean?

A digital filter is a system that performs mathematical operations on a discrete and sampled time signal,
so as to enhance or reduce certain aspects of that particular signal as may be
necessary. It is largely used in signal processing and differs from an analog
filter, which is an electronic circuit working with continuous signals. Digital
filters are expensive compared to analog ones, but they can turn many impractical or impossible designs into possibilities. In everyday life, they can
be found in devices like cell phones, radios and audio/video receivers.


Techopedia Explains Digital Filter

A digital filter contains an
analog-to-digital converter (ADC), which samples the signal coming in as
input, a microprocessor and some other components for storing filter
coefficients and data. There is also a digital-to-analog converter that is
present just before the output stage. The software that runs on the
microprocessor implements a digital filter by acting on a number from
the ADC and performing mathematical operations. It can perform several effects
such as amplification and delay on the sample signal.

The behavior of a
digital filter is also important. Different mathematical approaches are
used for understanding the reactions. The simplest way is to analyze the
response when a simple input is passed to the filter, for example an impulse.
Then based on the result, complex inputs can also be analyzed.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.