User manual

Chapter 6 To Make Measurements RIGOL
DS1000Z User’s Guide
6-7
4. Vertical Scale
Press Scale and use to adjust the vertical scale of the operation results.
5. Center Frequency
Press Center to adjust the frequency of frequency domain waveform relative to
the horizontal center of screen.
6. Horizontal Scale
Press Scale and use to adjust the horizontal scale of frequency domain
waveform.
7. Select Window Function
Spectral leakage can be considerably decreased when a window function is used.
DS1000Z provides four kinds of FFT window functions which have different
characteristics and are applicable to measure different waveforms. You need to
select the window function according to different waveforms and their
characteristics. Press Window to select the desired window function and the
default is “Rectangle”.
Table 0-1 Window Functions
Window Characteristics
Waveforms Suitable for
Measurement
Rectangle
The best frequency
resolution;
the poorest amplitude
resolution;
similar to the situation
when no window is
multiplied.
Transient or short pulse, the
signal levels before and after the
multiplication are basically the
same;
Sine waveforms with the same
amplitude and rather similar
frequencies;
Wide band random noise with
relatively slowly changing
waveform spectrum.
Hanning Better frequency resolution;
poorer amplitude
resolution.
Sine, periodic and narrow band
random noise.
Hamming A little bit better frequency
resolution than Hanning
Transient or short pulse, the
signal levels before and after the
multiplication are rather different.