Transform your ADALM Pluto SDR into a budget-friendly 0.1–3 GHz network analyzer using a $15 RF bridge!

🎬 Watch the full video demo and tutorial on YouTube:

This interactive Python application turns your ADALM Pluto SDR into a powerful network analyzer capable of measuring S21 (insertion loss/gain) and S11 (return loss) over a 0.1–3 GHz span. Key features include:

• FFT-based FIR lock-in for tone detection
• Interactive S21 & S11 calibration workflows (LOAD & OPEN)
• Skip-mask to reject invalid S11 data
• Moving-average smoothing toggle
• Interactive markers (left-click to add, right-click to clear)
• Maximum S11 clamp at 0 dB

Ideal for RF enthusiasts, hobbyists, and professionals seeking a low-cost network analyzer alternative.

• Wideband sweep: 0.1–3 GHz, configurable start/stop frequencies & step count
• Calibration workflows: Perform LOAD and OPEN calibration at the press of a button
• Live plotting: Dual-panel Matplotlib GUI with S21 (top) & S11 (bottom)
• Smoothing & raw toggle: Show raw data points or smoothed curves
• Markers: Click to annotate dB & frequency values
• Excel export: S11 calibration writes s11_calibration.xlsx automatically

• Python 3.8+
• libiio & pyadi-iio
• NumPy
• SciPy
• Matplotlib
• Pandas
• PyQt6

Install dependencies via:

pip install numpy scipy matplotlib pandas pyqt6 pyadi-iio

1. Clone the repo:

   git clone https://github.com/fromconcepttocircuit/pluto-network-analyzer.git
   cd pluto-network-analyzer

2. Install Python dependencies (see requirements above).

3. Connect your ADALM Pluto SDR to your network (default URI: ip:192.168.2.1).

1. Run the GUI:

   python network_analyzer.py

2. Set sweep span: Enter start/stop frequencies (MHz) and number of steps, then click Apply.

3. Calibrate S21: Click Cal S21, wait for the progress dialog to finish. The application will automatically save cal_s21.npz in the working directory and load it into the session.

4. Calibrate S11: Click Cal S11. When prompted, connect a 50 Ω load and click OK, then connect an OPEN termination and click OK. The tool will save cal_s11_load.npz, cal_s11_open.npz, and export s11_calibration.xlsx automatically, then load the new calibration.

5. Auto-load on startup: On next launch, if the .npz and .xlsx files exist, the application will load them automatically. You can also reload them at any time using Load S21 and Load S11 buttons.

6. Plot & analyze: Toggle smoothing/raw display, and click on the plots to add markers showing dB & frequency.

Note: Calibration files are generated and retrieved at runtime. Recalibrate any time to refresh measurement accuracy.

├── network_analyzer.py    # Main application script
└── README.md             # This document

For more tutorials and deep dives into RF & SDR projects, visit my YouTube channel:

From Concept to Circuit

This project is released under the MIT License.

Happy hacking! 🚀