Technical data

Measure (Spectrum Analysis Mode) 14
Agilent N8201A Performance Downconverter Synthetic Instrument Module, 250 kHz to 26.5 GHz 253
Harmonic Distortion
The range table state determines which harmonics are to be measured. If Range Table is
set to Off, for each harmonic to be measured, the center frequency will be set to the
appropriate integer multiple of the fundamental frequency and a sweep taken. The
amplitude is calculated by averaging the power in the trace and is displayed in the results
table in the results window. The desired Res BW value for each harmonic is calculated by
multiplying the harmonic number with the Res BW of the fundamental. This results in the
smallest Res BW available being used that is greater than or equal to the computed value. If
a Res BW greater than the instrument maximum is calculated then the maximum Res BW
of the instrument is used and an asterisk (*) is displayed after the amplitude result of the
harmonic to indicate that the desired Res BW was not used. The span for each harmonic is
set to zero.
If Range Table is set to On, for each range enabled after the fundamental, the center
frequency will be set to the frequency of each range. If the current span is set to zero, the
amplitude is calculated by averaging the power in the trace and is displayed in the results
table in the results window. If the range has a non-zero span, the amplitude is calculated by
making a band-power measurement over the span and is displayed in the results table in
the results window.
After the specified number of harmonics have been measured and their amplitudes
displayed, the total harmonic distortion is computed and displayed in the left-hand portion
of the window (view is set to Harmonics & THD). If the measurement is in single mode, the
display will remain at the last harmonic setting and the analyzer sweep will be stopped. If
the measurement is in continuous mode, the measurement will continually measure the
amplitude of the fundamental and harmonics.
For averaged measurements, you may specify the number of sweeps over which the
amplitude of each harmonic is measured. This means that if the Avg Number is set to 10,
ten sweeps will be taken and averaged for each harmonic to be measured. The total
harmonic distortion would then be calculated from these averaged amplitude readings.
Note that averaging applies only to the amplitude of the harmonic, and does not affect the
frequency at which the amplitude is measured.
Key Path: MEASURE
Dependencies/Couplings: This measurement is not available when using external
mixing.
Remote Command:
Measurement Results Available
Command n Results Returned
:CONFigure:HARMonics
:INITiate:HARMonics
N/A Not Applicable