DSP Tech Brief : One-Pole Filters

One-pole filters are very useful and efficient techniques for filtering signals. The feedback a value can also be used to design efficient peak-hold filters in the time-domain and are also used in power spectrum analysers and can help extract features of the signals that we are analyzing.

The following equation defines the one-pole filter :

y(n) = x(n) - a * y(n-1), 0 < a < 1.0

The single coefficient defines the gain and time-constant of the filter as follows :

Time constant :

Gain :

This algorithm is included in the SigLib DSP Library.

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Numerix-DSP Libraries : http://www.numerix-dsp.com/eval/