What is Aliasing?
A phenomenon in which components above half the sampling frequency falsely appear as lower-frequency components. It is prevented with a low-pass filter before A/D conversion.
Field: AD/DA conversion
Aliasing in the explanations
The Nyquist frequency is 6 kHz, and 10 kHz exceeds it, so it folds back and appears at |fs − f| = |12 − 10| = 2 kHz (aliasing).
If a 10 kHz sine wave is sampled at 12 kHz without an anti-…Butterworth filters are common as anti-aliasing filters before ADCs.
Which correctly describes a Butterworth low-pass filter?The sampling rate must exceed twice the signal's highest frequency (the sampling theorem), or aliasing occurs.
Which correctly describes "sampling" in AD conversion?
Questions that mention Aliasing (6)
- What sampling frequency is needed to sample an analog signal containing components up to 20 kHz without aliasing?
- What type of filter is used as the anti-aliasing filter placed before an AD converter?
- If a 10 kHz sine wave is sampled at 12 kHz without an anti-aliasing filter, at what frequency does it appear?
- Which correctly describes a Butterworth low-pass filter?
- Which correctly describes "sampling" in AD conversion?
- What is the technique of deliberately sampling a signal centered at 70 MHz with a 10 MHz bandwidth at a lower sampling frequency, which also performs frequency conversion?
Related terms
Nyquist frequency Sampling theorem Correlated double sampling (CDS) Jitter Delta-sigma ADC DNL (differential nonlinearity) ENOB (effective number of bits) Flash ADC INL (integral nonlinearity) Missing code