Howtosignalprocessing
- Why is it necessary to introduce an analog low-pass filter before analog to digital converter?
- What is low-pass analog signal?
- How does low-pass filtering convert discrete time signals into analog signal?
- Why use analog filters?
Why is it necessary to introduce an analog low-pass filter before analog to digital converter?
The analog low-pass filter can remove high frequency noise and interference from the signal path prior to the ADC conversion to help avoid contaminating the signal with aliased noise. It also eliminates the effects of overdriven signals beyond the bandwidth of the filter to avoid modulator saturation.
What is low-pass analog signal?
A low-pass filter (LPF) is a circuit that only passes signals below its cutoff frequency while attenuating all signals above it. It is the complement of a high-pass filter, which only passes signals above its cutoff frequency and attenuates all signals below it.
How does low-pass filtering convert discrete time signals into analog signal?
Before encountering the analog-to-digital converter, the input signal is processed with an electronic low-pass filter to remove all frequencies above the Nyquist frequency (one-half the sampling rate). This is done to prevent aliasing during sampling, and is correspondingly called an antialias filter.
Why use analog filters?
Analog filters have the main advantage of speed. Filtering with hardware means that the signal coming out of the physical filter is the final signal. Analog filters also provide a greater dynamic range for frequency.
