Did You Know LabVIEW Could Build a Real-Time Spectrum Analyzer ?

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The combination of LabVIEW and modular instruments with user-programmable FPGA helps you create a real-time spectrum analyzer that can trigger at frequency-specific amplitudes and log data to disk.

Traditional RF spectrum analyzers suffer from the fact that they are not capable of triggering on signals at specific frequencies of arbitrarily short durations.
Modern packed-based communication protocols generate such brief signals that it can be challenging to detect and troubleshoot them with traditional instrumentation. With the rich, custom visualization capabilities of NI LabVIEW software, you can convey a variety of information on a single display, including a frequency-dependent trigger threshold, peak values at each frequency, and a persistence display showing the average signal content with a variable intensity and decay rate.
But how do you overcome the hardware limitations of traditional RF spectrum analyzers? With NI modular instruments and Digital Signal Processor (DSP)-focused, field-Programmable Gate Arrays (FPGA) on the NI FlexRIO and Intermediate Frequency (IF) transceiver products, you can use the LabVIEW FPGA Module to implement custom RF applications. In the case of a real-time spectrum analyzer, the NI PXle-5641R RIO IF transceiver acquires IF data that has been downconverted from the RF frequency of interest.
On the FPGA, signal processing express Vls, such as windowing and the Fast Fourier Transform (FFT), give you the ability to continuously convert time-domain RF data into the frequency domain.
These computations can be performed faster than the incoming data, making them real time, which is possible only on today's high-performance FPGA. Once the data is in frequency domain, you can average it, record the peak value at each frequency, or compare it to a frequency-specific threshold and signal the host application to perform operations such as pausing the display or logging a record to disk whenever the threshold is exceeded. Only with the flexibility of LabVIEW can you use the same programming language on both the host microprocessor and other computing targets, such as FPGA to create unique, high-performance applications for test and measurement.

To watch a video of this real-time spectrum analyzer in action, visit ni.com/info.