A user configurable Spectrum Analyzer Application featuring a frequency range from 10 MHz to 3.5 GHz and a maximum resolution bandwidth of 15 MHz using a Lime SDR (Software-Defined-Radio) Mini. QT Creator IDE has been used.
See an example spectrum Center Frequency: 960 MHz, Span: 40MHz, Resolution Bandwidth: 10 MHz, Clear Write
See an example spectrum Center Frequency: 960 MHz, Span: 40MHz, Resolution Bandwidth: 10 MHz, Averaging Factor 30, Channel Bandwidth Measurement with 20 MHz BW and Marker placed
See the hardware setup
This project is still under development. Current features include
- Setting the following common Spectrum Analyzer settings upon creating a trace Center Frequency, Span, Resolution Bandwidth, Gain, Reference Amplitude and Trace averaging.
- Plotting the Spectrum (using Gnuplot)
- Creating an own trace for each LimeSDRmini connected
- Setting up to 3 markers in the plot
- Performing a Channel Power Measurement
The following topics are to be tackled soon
- Remove the DC bias and center spike (caused by the SDR) from the spectrum
- Changing of Spectrum Analyzer settings on the fly (right now the created Trace object needs to be destroyed and a new to be created)
- Use the (internal) second Rx channel for frequencies greater than 2 GHz
- A GUI with a similar user interface as one is accustomed to from spectrum analyzers
- Release as ver. 1.0 standalone application once the topics above are implemented
The following external libraries sources are used for this project and are required for using the code published in this repository
-
limesuite (SDR driver) Link
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gnuplot_i (Plotting API) (sourcefile and header already include in this repo)
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Gnuplot Link (Version 5.4.3 is tested and working)
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fftw3 (Fast-Fourier-Transformation) Link
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Run and modify the code in Lime_SDR_Spectrum_Analyzer.cpp to your liking
#include fftw3.h
#include limesuitelimesuite.h
#include gnuplot_i.h
float_type centerFreq = 965e6;
float_type span = 40e6;
float_type sample = 10e6;
double gain = 25;
double refAmp = -15;
int FFTlength = 1024;
int averaging = 30;
unsigned nTrace = 1;
Trace Trace1 = Trace(centerFreq, span, sample, gain, refAmp, FFTlength, averaging, nTrace);
Trace.Aqcuire_Sweep();
Pull requests are welcome. For major changes, please contact me under fabian.toeroek98@gmail.com to discuss your ideas.