Tektronix WCA200A, User Manual

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FFT and RBW
WCA230A & WCA280A User Manual
3- 179
Figure 3--127 outlines how frequency domain data is generated from time
domain data. The FFT window serves as a bandpass filter between time and
frequency domain data. The FFT frequency resolution and amplitude accuracy of
each frequency component depends on the window shape.
Frequency
Time domain data
FFT window
Time
Time domain data resulting
after windowing process
Frequency domain data
¢
FFT
Figure 3- 127: Windowing process of time domain data
Generally, window frequency resolution is inversely proportional to the accuracy
of measuring amplitude levels. For ordinal measurements, select the window
capable of separating the desired frequency component. Such a window
maximizes the accuracy of measuring amplitude levels and minimizes leakage
error while separating each frequency component.