About The Polynomial Function - R&S SGT100A User Manual

®
R&S SGT100A
●
d is the
region and controls the shaping.
The detroughing factor (d) can be set manually or derived from the selected V
value. In the latter case, it is calculated as follows:
d = V
See
A "Detroughing Factor = 0" defines a linear function.
See also
on page 152.

About the Polynomial Function

The polynomial function is an analytical method to describe a shaping function. The
polynomial function is defined as follows:
f(x) = a
●
Depending on the "Envelope Voltage Adaptation" mode, f(x) is:
–
–
●
The polynomial order n, the polynomial constant a
to a
on page 176
●
x depends on the "Envelope Voltage Adaptation" mode, see
The default polynomial function with n = 1, a
tion.
See also
●
Figure 7-20
●
"Converting Shaping Functions and Understanding the Displayed Values"
on page 152.
File format of the polynomial function file
You can store a polynomial function in a file or even define the polynomial coefficients,
store them as a file and load this file into the instrument. The polynomial files are files
with extension *.iq_poly.
The file contains an optional header # Rohde & Schwarz - IQ Output
Envelope Polynomial Coefficients # a0,a1,a2,... and a list of comma-
separated coefficient values.
Example: Polynomial function file content
# Rohde & Schwarz - IQ Output Envelope Shaping Table
# a0,a1,a2,...
0.135,0.91,0.34,-0.59,-0.11
User Manual 1176.8674.02 ─ 07
Detroughing Factor
/V
cc,min cc,max
Couple Detroughing Factor with
"Converting Shaping Functions and Understanding the Displayed Values"
+ ∑(a ), where n ≤10 and:
n
*x
0 n
f(x) = V (x) in "Auto Power"
cc
f(x) = V /V (x) in "Auto Normalized/Manual"
cc cc,max
are user-definable, see
n
Generation of Envelope Tracking Signals
(d), that limit the supply voltage V
Vcc.
0
Chapter 7.5.7, "Polynomial Coefficients
= 0 and a
0
Signal Generator Settings
in the low-power
cc
, and polynomial coefficients a
Setting",
Table 7-6
= 1 describes a linear func-
0
cc
0
150