Which filter characteristic passes signals above a cutoff frequency and attenuates lower frequencies?

Which filter characteristic passes signals above a cutoff frequency and attenuates lower frequencies?

• A. High Pass Filter
• B. Low Pass Filter
• C. Band Stop Filter
• D. Notch Filter

Answer: (A)

High-pass filtering is the idea here: it passes signals above a cutoff frequency and attenuates lower frequencies. The high-frequency parts of a signal—the rapid changes—go through with little loss, while slow, drifting components at lower frequencies are reduced. The cutoff marks where the response starts to decrease, often defined at the -3 dB point in practical designs. This makes high-pass filters useful for removing baseline wander or low-frequency noise while preserving the faster, informational content of the signal. By contrast, a low-pass filter would do the opposite, letting low frequencies through and attenuating high frequencies; a band-stop or notch filter suppresses a specific range of frequencies, not everything above a threshold.

High-pass filtering is the idea here: it passes signals above a cutoff frequency and attenuates lower frequencies. The high-frequency parts of a signal—the rapid changes—go through with little loss, while slow, drifting components at lower frequencies are reduced. The cutoff marks where the response starts to decrease, often defined at the -3 dB point in practical designs. This makes high-pass filters useful for removing baseline wander or low-frequency noise while preserving the faster, informational content of the signal. By contrast, a low-pass filter would do the opposite, letting low frequencies through and attenuating high frequencies; a band-stop or notch filter suppresses a specific range of frequencies, not everything above a threshold.