516 Keysight N9927-90001 User’s Guide
AM/FM Metrics (SA Only and Option 355)
SINAD and THD Calculations
SINAD and THD Calculations
— FieldFox converts the audio waveform to the audio frequency spectrum
using an FFT (i.e., The FFT result is not displayed). Refer to Figure 25-4 on
page 516.
— The FFT waveform is used to calculate SINAD and THD distortion metrics
— The fundamental signal, harmonics, and noise from 0 Hz to 24 kHz are
applied to the formulas. Refer to Figure 25-5 on page 517.
— For more on calculations, refer to “Overview of Measurement Types” on
page 509.
— See also, http://literature.cdn.keysight.com/litweb/pdf/5991-4913EN.pdf
Figure 25-4 Audio Waveform with FFT Calculations