Tektronix RSA2200A, User Manual

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FFT and RBW
3- 104
RSA2203A & RSA2208A User Manual
The Real Time S/A mode has FFT overlap capability that computes FFT
while overlapping 1024-point FFT frames by a specified number of samples.
The RBW/FFT menu contains the following controls:
NOTE
. In the Real Time S/A mode, the FFT points is always 1024 and FFT-
processed data does not go through RBW process (see Figure 3--78 on
page 3--103).
FFT Start Point.
Sets the start point of the 1024-point FFT frame by the
number of samples from the previous frame (see Figure 3--79).
Range: 1 to 1024 samples in increments of 2
n
.
FFT Overlap. Displays the amount of overlap between frames used to calculate
consecutive FFTs (see Figure 3--79). Not settable. The sum of FFT Overlap and
FFT Start Point is always 1024.
FFT Window... Selects the FFT window (window function).
For the window type, refer to Table 3--11 on page 3--108.
The default is Blackman-Harris 4B.
Time-domain data
Frame 1
Frame 2
Frame 3
FFT
Start Point
Time
FFT
Overlap
1024 points
S S S
Figure 3- 79: FFT overlap
Real Time S/A Mode