Using Features for Advanced Applications
TDS 500C, TDS 600B, & TDS 700C User Manual
3–207
The FFT windowing acts like a bandpass filter between the FFT time domain
record and the FFT frequency domain record. The shape of the window controls
the ability of the FFT to resolve (separate) the frequencies and to accurately
measure the amplitude of those frequencies.
FFT Time Domain Record
FFT Time Domain Record After
Windowing
FFT Window
FFT Frequency Domain Record
FFT
Xs
Figure 3–99: Windowing the FFT Time Domain Record
Selecting a Window. You can select your window to provide better frequency
resolution at the expense of better amplitude measurement accuracy in your FFT,
better amplitude accuracy over frequency resolution, or to provide a compromise
between both. You can choose from these four windows: Rectangular, Hamming,
Hanning, and Blackman-Harris.