Signal Generator Settings
R&S
®
SGT100A
148
User Manual 1176.8674.02 ─ 07
7.5.2.2
Signal Parameters for Testing According to the eTrak
®
Specification
In the R&S
SGT, you can select one of the predefined eTrak
®
interface types so that
the generated signal is conform with the MIPI
®
Alliance specification "Analog Reference
Interface for Envelope Tracking Specification".
Table 7-5: Default parameters per eTrak
®
Interface Type
Parameter
1.2 Vpp
1.5 Vpp
2 Vpp
I/Q output Type
Differential
Differential
Differential
Bias
500 mV
600 mV
900 mV
Vpp Max
1.2 V
1.5 V
2 V
Vcc Max
1.2 V
1.5 V
2 V
Bipolar Input
On
On
On
7.5.2.3
Envelope Shaping and Shaping Methods
Envelope shaping is a method that uses functions to describe the relationship between
supply voltage and RF input power. An envelope shaping function is a trade-off
between effectivity and improved linearity of the PA.
In the R&S
SGT, you can select the way you define the shaping function. You can
choose between:
●
2 predefined simple linear functions
(see
●
3 detroughing functions with a configurable factor
(see
"About the Detroughing Function"
●
A polynomial function with up to 10 polynomial coefficients
(see
"About the Polynomial Function"
●
A shaping function defined as a shaping table
(see
●
To set the correction values in raw format with a single remote control command
(see
"Shaping Function in Raw Data Format"
The linear, the detroughing and the polynomial shaping functions are mathematical
expressions that are described as function of the variable x, see
.
Table 7-6: Definition of the variable x depending on the envelope voltage adaptation mode
"Envelope Voltage Adaptation"
x
Auto Power
x = V
in
- V
in, min
x
≥
0
Auto Normalized
x = V
in
/V
in,max
Manual
x = V
Env
/V
Env,max
The mathematical expressions and further information on the shaping functions are
provided in the corresponding sections.
Generation of Envelope Tracking Signals
