Exceed 500 MS/s IQ Rate with PXIe-5668R

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Overview

Obtain IQ data on NI PXIe-5668R using fully specified bandwidth (765MHz) of the device.

Description

There are two out of the box solutions for running a continuous acquistion with the PXIe-5668R.  Streaming capabilities with IQ Rates greater than 500 MS/s can be attained by using either the Streaming Sample Project that ships with the RFSA 14.1 driver or by using the attached VI. The two methods are described as follows:

5668R Streaming Sample Project

This project can be found in the Create Project dialog box after the LabVIEW Getting Started Window or at the following file path:

<National Instruments>\LabVIEW 20XX\ProjectTemplates\Source\5668R\Streaming

The IQ Rate for this sample project is not specified directly by the user.  The IQ Rate is set indirectly based on the parameter set for the Desired Filter BW numeric control. On the block diagram, this IQ rate is derived from the Device Instantaneous Bandwidth and Desired Filter BW values. For example, a filter bandwidth set for 765 MHz produces a IQ Rate of about 950 MS/s. Please see Figures 1-3 in the Additional Images section for a depiction of these parameters.

Example Code

In order to utilize the full bandwidth of the PXIe-5668R, the device will need to be configured to use the 800 MHz bitfile. This attached example will initialize the device with the proper bitfile based on the input for the IQ Rate. If an IQ rate is defined higher than 500 MS/s, the 800 MHz bitfile will be used for the device. The 800 MHz bitfile permits higher IQ Rates to be set.

Steps to Implement or Execute Code

1. Run VI
2. Push Stop Button When Finished Acquiring

Requirements

Software

LabVIEW 2014 or greater

NI-RFSA 14.1 or greater

Hardware

NI-PXIe-5668R

Additional Images

Figure 1 - Bandwidth parameters used to determine IQ Rate

Figure 2 - IQ Rate derived from Instantaneous Bandwidth value

Figure 3 - Desired Filter BW value yielding an IQ Rate greater than 500 MS/s