User Guide

Chapter 5 Modulated Waveform Output RIGOL
DG4000 Series User’s Guide
5-23
QPSK
When QPSK (Quadrature Phase Shift Keying) is selected, you can configure the
generator to “shift” its output phase among four preset phases (“carrier phase”
and three “modulating phases”). The “shift” frequency (QPSK rate) is determined
by the internal signal level of the instrument.
To Select QPSK Modulation
Press Mod  Type  QPSK to enable QPSK function.
 When Mod is enabled, Sweep or Burst will be automatically disabled (if
enabled currently).
 After QPSK is enabled, the instrument will generate QPSK waveform with the
currently specified carrier and modulating waveforms.
To Select Carrier Waveform Shape
QPSK carrier waveform could be Sine, Square, Ramp or arbitrary waveform
(except DC), and the default is Sine.
 Press the front panel key Sine, Square, Ramp or Arb  Select Wform
(or User, the pre-defined waveform can not be DC) to select desired carrier
waveform shape.
 Pulse (basic waveform), Noise and DC could not be used as carrier waveform.
To Set Carrier Phase
After carrier waveform shape is selected, press Start Phase to highlight it and use
the numeric keyboard or direction keys and knob to input the desired phase. The
phase range is from 0º to 360º and the default is 0º.