Calculadora de Taxa de Amostragem de Nyquist
Calcule a taxa de amostragem mínima de Nyquist para digitalizar sinais sem aliasing.
Minimum (Nyquist) Rate
40.0 kHz
Minimum (Nyquist) Rate vs Maximum Signal Frequency
Formula
## Nyquist-Shannon Sampling Theorem ### Formula **f_sample >= 2 x f_max** The minimum sampling rate must be at least twice the highest signal frequency to avoid aliasing. In practice, sample at 2.5x or higher and use an anti-aliasing filter.
Exemplo Resolvido
Audio signal with 20 kHz maximum frequency, 2.5x oversampling.
- 01Nyquist rate = 2 x 20 = 40 kHz (minimum)
- 02Practical rate = 2.5 x 20 = 50 kHz
- 03Sample period = 1000 / 50 = 20 us
Perguntas Frequentes
What is aliasing?
When sampling below Nyquist rate, high frequencies fold back as false lower frequencies, corrupting the signal irreversibly.
Why oversample?
Real anti-aliasing filters cannot have infinite roll-off. Oversampling provides margin for the filter transition band.
Why is CD audio 44.1 kHz?
Human hearing extends to ~20 kHz. Nyquist requires 40 kHz minimum. The extra 4.1 kHz provides margin for the anti-aliasing filter.
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