FFT分辨率计算器 — 公式

The Nyquist-Shannon Sampling Theorem

To perfectly reconstruct a signal, you must sample at least twice the highest frequency present.

Formula

f_Nyquist = f_sample / 2

Any signal component above the Nyquist frequency will alias (fold back) into the baseband, creating distortion. This is why anti-aliasing filters are placed before ADCs.

Common Examples

  • CD audio: 44.1 kHz sampling, 22.05 kHz Nyquist
  • Phone: 8 kHz sampling, 4 kHz Nyquist
  • Professional audio: 96 kHz sampling, 48 kHz Nyquist

    • 计算示例

    CD-quality audio at 44,100 Hz sampling rate.

    1. Nyquist frequency: 44,100 / 2 = 22,050 Hz
    2. In kHz: 22.050 kHz
    3. Sampling period: 1,000,000 / 44,100 = 22.676 microseconds