Emerson R&S SGT100A User Manual page 212

®
R&S SGT100A
2. Select "Shaping > Polynomial".
3. Select "AM/PM > Polynomial Coefficients".
Figure 6-25: Polynomial Coefficients: Understanding the displayed information
n
a0, b0, ... = Polynomial coefficients
1
2
3
4
With the provided settings, you can define a polynomial function with up to 10
order to describe the predistortion function.
The graphical display updates on-the-fly and visualizes the resulting AM/AM and
AM/PM functions.
4. Select "Polynomial Order = 4" (n = 4).
5. Set the polynomial coefficients a
6. Select "Apply".
The instrument loads the configured values, calculates the correction values, and
displays the predistortion functions.
User Manual 1176.8674.02 ─ 12
= Polynomial order
= Ideal AM/AM function (the normalized amplitude is a line).
= Resulting AM/AM predistortion function, calculated as AM/AM(x) = abs[P
= Ideal AM/PM function (constant phase at 0 degrees)
= Resulting AM/PM predistortion function, calculated as AM/PM(x) = tan
Re[P (x)]}
DPD
Applying digital predistortion
to b .
0 4
Signal generator settings
(x)]
DPD
-1
{Im[P (x)]/
DPD
th
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