Modulation EN ⚫ The phase range is from 0є to 360є and the default is 180є. 8.9 QPSK Modulation Users can configure the instrument to "shift" its output phase between four preset values using QPSK modulation. The rate at which the output shifts between the four phases (called the "carrier phase" and three "modulation phases") is determined by the internal signal level of the instrument. 8.9.1 Select QPSK Modulation Press [Mod] > Type > QPSK softkey to enable QPSK function. ⚫ When Mod is enabled, Sweep or Burst will be disabled automatically. ⚫ After QPSK is enabled, the instrument will generate QPSK waveform with the currently specified carrier and modulating waveforms.
To avoid multiple waveform changes, enable modulation after configuring the other modulation parameters. 8.9.2 Carrier Waveform Shape QPSK carrier shape: Sine (default), Square, Ramp, Pulse, Arbitrary (except DC) or Harmonic waveform. ⚫ Press [Wave] button on the front panel to select the desired carrier waveform. ⚫ Noise and DC could not be used as carrier waveform. 8.9.3 Carrier Waveform Phase Press [Setting] > Phase softkey on the front panel and use the numeric keypad or direction keys and knob to input the desired phase. The available phase ranges from 0є to 360є and the default value is 0є. 8.9.4 Modulation Source QPSK uses the internal modulation source.
After enabling QPSK modulation function, press [Mod] > Data Source softkey, and select PN15 and PN21 codes as the modulation source. The default is PN15 code. 8.9.5 QPSK Rate When internal modulation source is selected, press [Mod] > Rate softkey to set the rate at which the output phase shifts between "carrier phase" and three "modulation HDG3000B User manual Copyright © Qingdao Hantek Electronics Co., LTD 50