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NI Wireless Test System (WTS) Calibration Procedure

Calibration Executive 4.0 Help

Edition Date: March 2017

Part Number: 374564H-01

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This topic contains information for calibrating the National Instruments Wireless Test System (WTS) using Calibration Executive.

Calibration Executive Procedure Features:


Adjustment Only

Optional Adjustment

Manual Mode

Selectable Test Points


Approximate Test Time:

Module Verify Only Verify & Adjust Adjust Only
WTS-01, -02, -03, -04 80 minutes 240 minutes 80 minutes
WTS-05 160 minutes 480 minutes 160 minutes
Test Equipment|Test Conditions|Device Setup|Test Limit Equations

Test Equipment

The following table lists the test instruments required for calibrating the WTS.

Instrument Recommended Model Minimum Requirements
Frequency reference Symmetricom 8040 Rubidium Frequency Standard Frequency: 10 MHz

Frequency accuracy: ±1E-9

Power sensor Rohde & Schwarz NRP-Z91 with NRP-Z4 USB adapter Range: -67 dBm to +23 dBm

Frequency range: 65 MHz to 6 GHz

Accuracy: 0.5%

VSWR: <1.2 at 6 GHz

Vector signal generator PXIe-5673E (NI 5673) Frequency range: 65 MHz to 6 GHz

Frequency resolution: <5 Hz

Amplitude range: -60 dBm to 0 dBm

Instantaneous bandwidth: 50 MHz

Spectrum analyzer or vector signal analyzer PXIe-5665 (NI 5665) Frequency range: 65 MHz to 6 GHz

Noise floor at 6 GHz: <-158 dBm/Hz

Instantaneous bandwidth: 50 MHz

Phase noise at 20 kHz offset: <-125 dBm/Hz

Preamplifier PXI-5691 (NI 5691) (x2) Frequency range: 65 MHz to 6 GHz

Noise floor at 6 GHz: <-158 dBm/Hz

Instantaneous bandwidth: 50 MHz

Phase noise at 20 kHz offset: <-125 dBm/Hz

6 dB attenuator (x3) Anritsu 41KB-6 or Mini-Circuits Frequency range: DC to 6 GHz

VSWR: 1.1

  • SMA (m)-to-SMA (m) cables
  • SMA (f)-to-N (m) adapters
  • SMA (m)-to-N (f) adapter
Frequency range: DC to 6 GHz

Impedance: 50 Ω

Test Conditions

The following setup and environmental conditions are required to ensure the NI WTS meets published specifications.

  • Keep cabling as short as possible. Long cables act as antennas, picking up extra noise that can affect measurements.
  • Verify that all connections, including front panel connections and screws, are secure.
  • Maintain an ambient temperature of 23 °C ± 5 °C.
  • Keep the relative humidity between 10% and 90%, noncondensing.
  • Allow a warm-up time of at least 30 minutes after the WTS and instrument chassis are powered on. The warm-up time ensures that the NI WTS and test instrumentation are at a stable operating temperature.
  • Ensure that the NI WTS and PXI Express chassis fan speeds are set to HIGH, that the fan filters (if present) are clean, and that the empty slots contain filler panels and slot blockers. For more information about chassis cooling, refer to the Maintain Forced-Air Cooling Note to Users document available at

Device Setup

  1. Use a monitor, a USB keyboard, and a mouse, and confirm that the WTS device is logged in and that the software is loaded.
    The WTS Instrument software must be loaded in order for external communication to be established with the device.
  2. Ensure that the WTS is connected to the same subnet as the system running Calibration Executive.
    Note that ethernet port 2 on the WTS is configured for DHCP by default
  3. Configure the hardware using Measurement & Automation Explorer (MAX). Refer to the NI Wireless Test System Getting Started Guide, available at, for troubleshooting information.
  4. Launch the Calibration Executive procedure. Calibration Executive guides you through the required connections.
    Note Note  You must have at least 4 GB of memory on your system to run this procedure. If you run the WTS on a 32-bit machine, it is recommended that you enable the Windows setting that expands the available user mode address space to 3 GB. Failure to do this may result in out-of-memory errors. To enable the Windows setting, open the command prompt and issue the following command:

    bcdedit/set IncreaseUserVA 3072

    Caution Caution  Using this command incorrectly can render your computer inoperable. Refer to Microsoft documentation on the BCDEdit /set command for more details. This command reduces the kernel address space available for Windows from 2 GB to 1 GB.

Test Limit Equations

The following test limits are derived from the published specifications.

Internal Frequency Reference Accuracy

TestLimits = (InitialAccuracy + TemperatureStability) + Aging

If Calibration Executive detects that the WTS device under test has not previously been adjusted, then the as found performance of the device will not be considered warranted, and the as found limits will reflect the unadjusted performance of the device. For more information, go to and enter the Info Code WTScalibrate.


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