NPR measures the nonlinear behavior of an RF microwave amplifier under a modulated signal stimulus.
In this topic:
See Noise Power Ratio (NPR) Measurement Example
Spectrum Analyzer Option S9x090xA/B
2- or 4-Port PNA with ability to connect an external modulated source
Supported external sources:
E8267D PSG Vector Signal Generator
M8190A with E8267D PSG Vector Signal Generator
M9383A/B, M9384B (wideband vector, 44 GHz, with enhanced phase noise)
Note: When setting up an M9383A, M9383B, or M9384B source in the External Device Configuration dialog, select MXG_Vector as the driver (they are code compatible).
N5182B MXG RF Vector Signal Generator
N5192A and N5194A UXG Vector Adapter
On the VNA front panel, press Meas > S-Param > Meas Class....
Select Spectrum Analysis, then either:
OK delete the existing measurement, or
New Channel to create the measurement in a new channel.
A Spectrum Analysis measurement is displayed.
Modulation source - Displays the name of the modulation source. Modulation File - Displays the modulation file name. Load File... button - Loads an existing modulation file. Create...- button - See Create Modulation dialog description. Edit...- button - See Create Modulation dialog description. Properties button - Displays the properties found in the modulation file. This is the active Modulation Filename selected in the Modulation settings dialog. This information cannot be edited. Enable Modulation - Check to enable modulation. DAC Scaling - Sets the scaling factor used for the waveform (full scale = 70%). This ensures that the DAC filter does not output a signal that is larger than the DAC's maximum output level, which can cause distortion in the system. Enable Modulation Correction - Automatically checked if user exits the calibration wizard with Exit & Save Cal. This option is grayed out if a modulation calibration has not been performed.Source Cal... button - Accesses the Modulation Cal - Setup dialog for performing source modulation calibration. Autoset Frequencies and Coherence for current modulation - Check to allow frequencies and coherence to be set automatically for the current modulation. Autoset NPR Markers Enables and disables NPR markers. Autoset ACPR Markers Enables and disables ACPR markers. NPR Band Guard - Guard band on each side of the notch in an NPR measurement. ACPR Band Guard - Guard band between the end of the modulation signal and where ACPR is measured. Immediate Autoset button - Click to adjust frequencies and markers if modulation settings are changed. Source Power - Sets the source power level. Source Path Amplification (= Power Offset) - Displays the Power Offset to monitor the power budget between the source and DUT. The Power Offset setting provides a method of compensating port power for added attenuation or amplification in the source path. Learn more. |