Rigol DS8000-R Series User Manual page 136

RIGOL
Spectral leakage can be considerably decreased when a window function is used.
DS8000-R provides 6 FFT window functions (as shown in Table 6-1) which have
different characteristics and are applicable to measuring different waveforms.
You need to select the window function according to the characteristics of the
waveform to be measured.
Table 6-1 Window Function
Window
Function
Rectangular
Blackman-Harris
Hanning
Hamming
Flattop
Triangle
For FFT math operation setting label, refer to descriptions in "Math Operation
⚫
Label".
Click More → More → Color Grade to enable or disable the color grade
⚫
display of the FFT operation results. When enabled, different colors are
displayed on the screen to indicate the times of data acquisition or acquisition
probability.
Click More → More → Reset ColorGrade to clear the color grade display and
⚫
6-8
Characteristics
Best frequency
resolution
Poorest
amplitude
resolution
Similar to the
situation when
no window is
applied.
Best amplitude
resolution
Poorest
frequency
resolution
Better frequency
resolution and
poorer amplitude
resolution
compared with
Rectangular
A little bit better
frequency
resolution than
Hanning
Measure the
signals
accurately
Better frequency
resolution
Chapter 6 Operations and Measurements
Waveforms Applicable to the
Window Function
Transient or short pulse, the signal
levels before and after the
multiplication are basically the same.
Sine waveforms with the same
amplitudes and rather similar
frequencies.
Wide band random noise with
relatively slow change of waveform
spectrum.
Single frequency signal, searching for
higher order harmonics.
Sine, periodic, and narrow band
random noise.
Transient or short pulse, the signal
levels before and after the
multiplication are rather different.
Measure the signal that has no
accurate reference and requires an
accurate measurement
Measure the narrow band signal and
that has strong noise interference
DS8000-R User Guide