Electronic filter

Electronic filters are a type of signal processing in the form of electronic circuits. Electronic filters remove unwanted frequencies from an applied signal, enhance wanted ones, or both.

Electronic filters can be:

• Passive or active,
• Analogue or digital,
• High-pass, low-pass, band-pass, band-stop (notch) or all-pass,
• and linear or non-linear;

With the filter operating in:

• Discreet-time (sampled) or continuous-time,
• and infinite impulse response (IIR) or finite impulse response (FIR).

The most common type of electronic filters are linear filters, regardless of other aspects of their design.