HighPass Filter
LowPass Filter
Numerical LowPass Filter
HighPass RC Filter:

 Capacitor passes high frequencies, blocks low
frequencies
 In frequency domain, capacitor impedance,
Z(ω)=1/jωc
 So, the impulse response,
 where,
 Whose magnitude,
 And phase,
 So that,
 G is easiest viewed on a Bode (loglog) plot:
 Φ is 0° for high frequencies, 90° at low
frequencies, and 45° at the 3dB point:
 Note: The affect of a highpass filter can be numerically
undone with the droop correction algorithm.
 LowPass
RC Filter:
 Capacitor
passes high frequencies, blocks low frequencies
 In frequency domain, capacitor impedance,
Z(ω)=1/jωc
 So, the impulse response,
 where,
 Whose magnitude,
 And phase,
 So that,
 G is easiest viewed on a Bode (loglog)
plot:
 Φ is 0° for high frequencies, 90° at low
frequencies, and 45° at the 3dB point:
Copyright © Raymond Allen
20062021