High-pass filter

A high-pass filter (HPF) is an <a href="/facts/Filter_(signal_processing)/vydJCNle">electronic filter</a> that passes <a href="/facts/Signal_(electrical_engineering)/41YqUJ8c">signals</a> with a <a href="/facts/Frequency/QUSbPaW8">frequency</a> higher than a certain <a href="/facts/Cutoff_frequency/vc8veeXp">cutoff frequency</a> and <a href="/facts/Attenuate/XP4vX360">attenuates</a> signals with frequencies lower than the cutoff frequency. The amount of <a href="/facts/Attenuation/XP4vX360">attenuation</a> for each frequency depends on the filter design. A high-pass <a href="/facts/Filter_(signal_processing)/vydJCNle">filter</a> is usually modeled as a <a href="/facts/Linear_time-invariant_system/kEmj0QDC">linear time-invariant system</a>. It is sometimes called a low-cut filter or bass-cut filter in the context of audio engineering. High-pass filters have many uses, such as blocking DC from circuitry sensitive to non-zero average voltages or <a href="/facts/Radio_frequency/aWku7h4R">radio frequency</a> devices. They can also be used in conjunction with a <a href="/facts/Low-pass_filter/QFsUjw7h">low-pass filter</a> to produce a <a href="/facts/Band-pass_filter/JyTCLleb">band-pass filter</a>.
In the optical domain filters are often characterised by wavelength rather than frequency. High-pass and low-pass have the opposite meanings, with a "high-pass" filter (more commonly "short-pass") passing only shorter wavelengths (higher frequencies), and vice versa for "low-pass" (more commonly "long-pass").

High-pass filter open-in-new

High-pass filter