Generation Of Envelope Tracking Signals; Required Options; About The Envelope Tracking - R&S SGT100A User Manual

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R&S SGT100A

7.5 Generation of Envelope Tracking Signals

The envelope tracking (ET) is a method used by modern power amplifiers (PA) to
improve their efficiency, especially when they amplify RF signals with a high peak to
average power (PAPR). An envelope tracking detector "tracks" the power variations in
the input signal of the PA; the PA then varies synchronously to this variation the supply
voltage v
This section introduces the concept of the envelope tracking functionality and the way
it is implemented in the R&S SGT.

7.5.1 Required Options

The equipment layout for generation and output of envelope tracking signal includes:
●
Option Differential Analog I/Q Outputs (R&S SGT-K16)
●
Option Envelope Tracking (R&S SGT-K540)
●
Optional option AM/AM AM/PM Predistortion (R&S SGT-K541)

7.5.2 About the Envelope Tracking

Provided the required options are installed, the R&S SGT allows you to generate an
envelope tracking signal, that follows the envelope variation of the RF signal.
Principle of the envelope tracking
The
ing. This illustration is intended to explain the principle in general, not all connections
and required equipment are considered.
Figure 7-9: Simplified test setup for power amplifier envelope tracking tests
The R&S SGT in this setup is configured to generate both, an RF signal with complex
modulation scheme and an envelope signal, that follows the envelope variation of this
RF signal. A suitable test signal is for example an EUTRA/LTE DL signal.
User Manual 1176.8674.02 ─ 07
at its end amplifying stage.
cc
Figure 7-9 shows a simplified test setup for testing of a PA with an envelope track-
Signal Generator Settings
Generation of Envelope Tracking Signals
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