Sweep Delay between PXIe-5646R and PXIe-5451 in Envelope Tracking Mode for RFIC PA Test (LabVIEW)

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Description

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Overview

This is an add-on example for the NI RFIC Test Software.

When using the PXIe-5646R and PXIe-5451 in envelope tracking mode, a very precise delay between the two instruments is required to achieve peak efficiency and performance out of a power amplifier (PA). This example allows the user to sweep a range of delays and perform an AMPM measurement at each delay in order to find the optimal delay required for further testing of RF performance.

Note: For an equivalent C# .NET example, please refer to this link: Sweep Delay between PXIe-5646R and PXIe-5451 in Envelope Tracking Mode for RFIC PA Test (C# .NET)

Description

 Use this VI as reference on how to set up a fast delay sweep with an RFmx AMPM measurement at each configured delay. There are two methods proposed: 

1. Fine Sweep Only: Sweep from (Initial Delay Estimate - Sweep Range) to (Initial Delay Estimate + Sweep Range) in (Sweep Step) steps
2. Coarse + Fine Sweep: Perform a coarse sweep to determine a first estimate of the optimal delay. Then perform a smaller sweep with the defined Sweep Step size around the first estimate to find the optimal delay. This method requires fewer steps and is usually faster.

After finishing with the delay sweep, the example will select the optimal delay and perform a RFmx ACP measurement to analyze the DUT's RF ouput performance. Note that many DUT-specific settings are required to be configured before running the example.

Hardware and Software Requirements

Hardware

• NI PXIe-5646R 
• NI PXIe-5451
• DUT (such as a power amplifier) capable of envelope tracking mode

Software

• NI RFSA 16.0
• NI RFSG 16.0
• NI FGEN 16.0
• NI RFmx SpecAn 2.2
• NI RFSG Playback Libraries 2.2
• NI RFIC Test Software 2.1 (required for NI ETSync functionality and VST bitfile)
• LabVIEW 2015 or later

Steps to Implement or Execute Code

1. Open the VI RFIC Msmt Example ET + Delay Sweep + ACP.vi
2. Configure the RFSG, ARB/Tracker and RFSA tabs on the VI's front panel to reflect the hardware setup used.
3. Configure the RFmx ACP measurement performed after the delay sweep using the ACP (General) and ACP (Channels) tabs. Note that the default measurement is configured for an LTE 10MHz waveform (with 2 UTRA and 1 E-UTRA offsets)
4. Configure the sweep parameters using the Delay Sweep tab. Make sure to select an appropriate initial delay estimate. You can also configure the AMPM measurement. 
   1. 
5. Run the VI
   1. In Fine Sweep Mode, you should see the AMPM sweep results under the Sweep Information tab:
   2. In Coarse + Fine Sweep Mode, you should see the AMPM sweep results under the Sweep Information tab:

Additional Information or References

NI RFIC 2.1 Test Software

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