Digital Modulation Quality

N5162A / N5182A Option 651, 652, or 654
N5172B Option 653 or 655 or 657
N5182B / N5182N Option 656 or 657

Error Vector Magnitude (EVM) is the magnitude of the vectorial difference between the measured signal and an ideal reference signal in the I-Q plane.

Global Phase Error is the magnitude of the phase difference between the measured signal and an ideal reference signal in the I-Q plane.

This test supports two different test setups using either a PXA (N9030A/B) signal analyzer with Vector Signal Analysis Application, or an 89441 vector spectrum analyzer. The PXA is the preferred solution.

1. A PXA-series (N9030A/B) signal analyzer is used with the 89600 Vector Signal Analysis Application to measure EVM and Global Phase Error.

   A PSA-series spectrum analyzer (E4443A, E4440A, or E4445A) with Option 241 (Flexible Digital Modulation Personality) and B7J (Digital Demodulation Hardware) and Option 123 (Preselector Bypass)4 may also be used to measure EVM and Global Phase Error.

   Test Equipment	Critical Specifications for This Test	Recommended Model	Alternate Models
   Signal Analyzer	EVM Accuracy	N9030B Opt 5xx1 and MPB2	N9030A Opt 5xx1 and MPB2 E4440A3 Opt 241, B7J, and 1234 E4443A3 Opt 241, B7J, and 1234 E4445A3 Opt 241, B7J, and 1234
   Vector Signal Analysis Application5		896006, 7 VSA with these options: 89601200C, basic vector signal analysis and hardware connectivity 89601AYAC, digital demodulation analysis 89601B7NC, 3G modulation analysis
   Select any frequency option of PXA signal analyzer (503, 508, 513, 526, 543, 544, 550) that has a maximum frequency greater than or equal to the maximum frequency of the unit under test. The N9030A/B Option 550 frequency range is adequate for all DUT frequency configurations. Firmware version A.11.04 or greater required. The E4446A, E4447A, E4448A are neither recommended nor suggested alternates for the Digital Modulation Quality test. Their specified performance may cause “false failures” of a unit that actually meets its EVM specifications. However, the N7800A TME software does allow these models to be used for the Digital Modulation Quality test, only because many units are found to perform adequately, and if the Digital Modulation Quality test passes using these models, the calibration results are valid. Option 123 required only if testing DUTs with Option 506 (6 GHz DUT). Required when using the N9030A/B. The N9030B requires version 21.0 or greater of the VSA software. This version of the software also requires the latest Keysight IO library. Refer to the Keysight website to get the latest IO library. If the VSA application version installed is less than version 2019 (eg. 89601B), then these options are required: 200, 300, AYA, B7T.

2. An 89441A vector spectrum analyzer is used to measure EVM and Global Phase Error. When using the 89441A, additional equipment is required for downconverting the signal above 2.65 GHz.

   Test Equipment	Critical Specifications for This Test	Recommended Model	Alternate Models
   Vector Signal Analyzer	EVM Accuracy	89441A Opt AYA, AYH, AY9, B7A, and UFG or UTH
   Mixer	Frequency Range: RF: L.O. Ports: 200 MHz – 20 GHz I.F. Port: 5 MHz – 6 GHz	0955-2225	0955-1017
   Local Oscillator	Output power1:  ≥ 16 dBm Frequency: 2 – 6 GHz	E8257D Opt [UNR or UNX or UNY]	E8241A Opt UNJ E8244A Opt UNJ E8251A Opt UNJ E8254A Opt UNJ E8247C Opt UNR E8257C Opt UNR E8267C Opt UNR E8267D Opt [UNR or UNX or UNY]
   10 dB Attenuator	None	8491B Opt 010	8490D Opt 010 8491B Opt 010 8493A Opt 010 8493B Opt 010 8493C Opt 010
   This test requires the Local Oscillator to be capable of at least 16 dBm output at all test frequencies. To ensure this requirement is met, a pre-check is done at the outset of the test by measuring the power from the Local Oscillator that is in use at several of the test frequencies. If during this pre-check the Local Oscillator cannot output enough power, the test will fail. This approach is meant to allow using the broadest range of models, as listed, but can result in disqualifying a chosen unit for failing to meet the power requirement.

Connections and Setup Procedures

For setup instructions using either the PXA or PSA signal analyzer, click here.

Test Setup Instructions for PXA with the Vector Signal Analysis Application

The PXA's firewall may need to be turned off. The PXA must be logged in as Administrator.

1. Install the 89600 Vector Signal Analysis Application on the same PC as TME. This PC must also be connected to the LAN.

2. Connect the PXA signal analyzer to the LAN.

3. Get the IP address of the PXA via the PXA’s front panel information system: System > Show > System.

4. Add the PXA to the LAN interface.

   If using Agilent IO libraries, click here.

   1. Open the Agilent Connection Expert for the Agilent IO libraries. If a LAN interface does not exist, add it:

      

   2. Add the PXA as an instrument on this interface using the IP address from step 3.

      

   3. Verify that the instrument has been successfully added to the interface.

      

       

    

   If using Keysight IO libraries, click here.

    

   See below for troubleshooting tips if using VSA software 89601B version 21.0 or greater with Keysight IO libraries.

   1. Open the Keysight Connection Expert for the Keysight IO libraries and add the PXA to a LAN interface by selecting Manual Configuration > Add New Instrument/Interfaces > LAN instrument.

   2. Add the PXA as a LAN device by entering the PXA's Hostname (preferred method) or IP address as shown below.

      Using the PXA's Hostname is the preferred method to avoid the possibility of crashing the software. The Hostname can be found in the PXA's System menu. An example of a Hostname is: K-N9030B-80323, where K = Keysight, N9030B = model, 80323 = last 5 digits of the serial number.

      

   3. Verify the instrument address by selecting Test This VISA Address, then select Accept.

      

    

5. Ensure the equipment is connected as shown (PXA or PSA):

   

    

For setup instructions using the 89441 VSA, click here:

Vector Spectrum Analyzer Test Setup

Setup for all RF frequencies

 

 

Setup for RF frequency ≤ 2650 MHz

 

Setup for RF frequency > 2650 MHz

Vector Signal Analysis Troubleshooting

When adding the PXA as LAN device, use the PXA's Hostname rather than the IP Address to avoid the possibility of crashing the software. The Hostname can be found in the PXA's System menu. An example of a Hostname is: K-N9030B-80323, where K = Keysight, N9030B = model, 80323 = last 5 digits of the serial number.

Troubleshooting tips if using VSA software 89601B version 21.0 or greater with Keysight IO libraries:

If the VSA software freezes during the Digital Modulation Quality test, manually verify that the you are able to “Rediscover Instruments” in the VSA software.

1. Open the VSA software and select Utilities >Hardware > Configurations…

2. Next, click on the Discover Instruments tab and click on the Rediscover Instruments button.

If this freezes, then you may need to set the Keysight VISA as the Preferred VISA. To set the Keysight VISA as the preferred VISA:

1. Open the Keysight Connection Expert and go to Settings > Visa Conflict Manager > General VISA Settings. Ensure Keysight VISA is set as the preferred VISA implementation as shown in the image below: