Electronic filter
electronic circuit that removes unwanted components from the signal, or enhances wanted ones, or both
Butterworth filter
elliptic filter
digital filter
Finite impulse response filter
Crystal filter
all-pass filter
audio crossover
notch filter
voltage-controlled filter
high-pass filter
band-pass filter
band-stop filter
distributed element filter
Active filter
infinite impulse response filter
waveguide filter
capacitor-input filter
low-pass filter
Comb filter