
Using the Scope Functions
3
Agilent U1602A/U1604A User’s and Service Guide
105
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Window
Press F4 to select any of the four FFT windows with respective trade- off
between frequency resolution and amplitude accuracy. Refer to the
following guidelines to select the best window based on your source
waveform characteristics and your measurement priorities.
• Rectangle
This window provides good frequency resolution and amplitude
accuracy. This window is best for measuring pseudo- random noise,
impulses, sine bursts and decaying sinusoids.
• Hamming
This window provides better frequency resolution but less amplitude
accuracy compare to Rectangle. The Hamming window has a slightly
better frequency resolution than Hanning, and is suitable for measuring
sine, periodic and asymmetric transients or bursts.
• Hanning
This window is similar to the Hamming window, used for making
accurate frequency measurement or resolving two frequencies that are
close together and performs similar applications to the Hamming.
• Blackman- Harris
This window provides the best amplitude resolution, but less frequency
resolution compared to the other three windows. This window is
normally used for measuring single frequency waveforms to obtain
higher order harmonics.
N O T E
To reduce the DC component that potentially affects the FFT waveform magnitude values,
choose AC coupling on the source waveform.