 Total Harmonic Distortion Measurements by Anritsu

Official Anritsu white paper. Printed p. 2, THD Definitions and Calculation Approach, distinguishes normalization to the fundamental from normalization to the full harmonic RMS sum. Printed p. 3 and Figure 1 describe source-power/receiver calibration across the measured harmonic frequencies. Printed pp. 4–7 demonstrate separate harmonic measurement channels and their root-sum-square combination.