YOU CAN BUILD THE 18,560-DOLLAR ANTENNA TEST RANGE FOR 989 DOLLARS
A university lab in Peru published a 989-dollar antenna test range, built as a low-cost alternative to an 18,560-dollar commercial system, that tracked the manufacturer's datasheet to within about 1.5 dB RMSE at 750 MHz.
by Alex Kana-Chuctaya and Alexander Hilario-Tacuri
ScienceOpen-hardware
Built withRaspberry Pi3D printing
- difficulty
- ●●●●●
- time
- a weekend-plus
- license
- GPL-3.0 (software), CERN-OHL-P v2 (hardware), CC BY 4.0 (documentation)
- repo
- repo FINISHED0 stars
●●●●● · a weekend-plus · GPL-3.0 (software), CERN-OHL-P v2 (hardware), CC BY 4.0 (documentation) · 0 stars · repo FINISHED
WHAT YOU’LL NEED
Jump to section
COMPAREE VERDICT
This is a working antenna radiation pattern measurement system published by a university research group in Peru and validated against a manufacturer datasheet at 750 and 2600 MHz. In the horizontal plane at 750 MHz the measured pattern differed from the datasheet by an RMSE of about 1.5 dB, and the worst case (vertical plane, 2600 MHz) was about 3.3 dB, all measured outside an anechoic chamber. It costs 989 dollars in parts where the commercial system the authors cite (MegiQ RMS-0460) is approximately 18,560 dollars, and the design files and code are published under open licences. The mechanical design is straightforward — 3D-printed antenna supports, a NEMA 17 stepper, a drive belt and a rotating platform — but the software is not. Separate Python threads run in parallel on the Raspberry Pi: transmit and receive on the bladeRF SDR, rotation control through the L298N driver, and a synchronisation thread that records the signal at each angle the rotation thread reports. An MOC70T3 optocoupler sets the 0° reference. The documentation is thorough and peer-reviewed, but it is written for someone who already understands antenna measurement principles, not for someone learning RF from scratch. The bladeRF is listed at 560 dollars in the paper's bill of materials, so the rest of the system — Raspberry Pi, touchscreen, stepper, driver, printed parts and antennas — comes to roughly 430 dollars. The one thing most likely to go wrong is angle accuracy: if the 0° reference is off or the stepper skips steps, the angle data will be wrong and the pattern will not match the datasheet. This is not a beginner project, but if you are already working with SDR and need to characterise custom antennas without access to a commercial test range, this is the published reference design.
IN THE REPO
GOOD TO KNOW
- —All design files, bill of materials, firmware, and documentation are published on the Open Science Framework (osf.io/kbm3f).
- —Hardware under CERN-OHL-P v2 (permissive, commercial use allowed), software under GPL-3.0 (open source, share-alike), documentation under CC BY 4.0 (attribution required).
- —This is a peer-reviewed academic publication in HardwareX, not a community GitHub repository — documentation is written for reproducibility, not step-by-step building.
- —The bladeRF 2.0 micro xA4 is listed at 560 dollars in the paper's BOM, more than half of the stated 989 dollars total cost.
- —Validation was performed at 750 MHz and 2600 MHz on one ultra-wideband antenna — other frequencies and antenna geometries are not characterised.
- —You need working knowledge of software-defined radio, RF measurement principles, and multi-threaded Python to configure and operate the system.
Parts to buy
9 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
More builds like this
All projectsGallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the HardwareX paper (The paper describes the system architecture, synchronisation method, and validation results. Start here to understand what you are building and why each component matters.)
- 2.Download the complete files from OSF (All CAD files, BOM, firmware, and documentation are published here. Check the BOM against current component availability before ordering.)
- 3.Order the bladeRF 2.0 micro xA4(This is the most expensive single component (560 dollars in the paper's BOM) and the one most likely to have lead time. Verify that the xA4 variant (47 MHz to 6 GHz) covers your target frequency before purchasing.)
- 4.Assemble the mechanical platform(Follow the CAD files for mounting the stepper motor, timing belt, and rotating platform. Test rotation manually before connecting the L298N driver.)
- 5.Wire and test the optocoupler 0° reference(The MOC70T3 optocoupler sets the 0° reference on the receiving antenna mount. Check on the bench that it triggers reliably at the same position every rotation before running a full pattern capture.)
- 6.Configure the bladeRF and run the multi-threaded control software(The software coordinates rotation, transmit/receive, and trigger synchronisation in parallel. Run a short test sweep first and verify that angle data matches physical rotation before capturing a full pattern.)
KNOWN ISSUES
- The bladeRF 2.0 micro xA4 is listed at 560 dollars in the paper's BOM, more than half of the total budget. If you buy a different SDR model or variant, the software and calibration may not transfer directly.
- Angle accuracy depends on the MOC70T3 optocoupler finding the 0° reference reliably and on the stepper never skipping steps after that. If the home position is off or the motor loses steps, every recorded angle shifts and the pattern will not match reality. Test homing and a full rotation before running a capture.
- The paper validates performance at 750 MHz and 2600 MHz on one ultra-wideband antenna. Other frequencies and antenna geometries are not characterised, so expect to recalibrate if you change the setup.
- This is peer-reviewed academic documentation, not a step-by-step maker guide. The paper assumes you already understand antenna measurement principles and software-defined radio — if you are learning RF for the first time, this is not the project to start with.
- The software runs separate threads for transmission, reception, rotation control and synchronisation alongside the main program, and they must coordinate without blocking or drifting. If you are not comfortable debugging multi-threaded Python on a Raspberry Pi, this will be the hardest part of the build.
- You are transmitting RF and rotating a mechanical assembly. Confirm that transmitting at your chosen frequency and power level is legal in your location, and ensure the rotating platform is secured and cannot strike anything.
Can I use a different SDR instead of the bladeRF?
The firmware is written for the bladeRF 2.0 micro xA4 and the paper does not characterise other SDR platforms. A different SDR may work, but you will need to rewrite the transmit/receive code and recalibrate the system.
What frequency range does this support?
The bladeRF 2.0 micro xA4 covers 47 MHz to 6 GHz and the authors state the system works from 70 to 5999 MHz. The paper validates performance at 750 MHz and 2600 MHz. You can measure other frequencies within that range, but expect to recalibrate.
How long does a full pattern capture take?
The paper does not state a capture time. Its validation sweeps used a 10° angle step over a full 360° rotation; a finer step means more measurement points and a longer sweep.
Do I need an anechoic chamber?
No. The authors validated it in a normal, non-anechoic room and use signal processing to compensate for measurement errors. Reflections from nearby walls, floors, or objects will still affect the measurement, so test in an open space or a room with minimal metal surfaces.
Is the measured pattern accurate enough for antenna certification?
The authors report an RMSE of 1.462 dB against the manufacturer datasheet in the horizontal plane at 750 MHz, and below 3.260 dB in every case they tested, measured outside an anechoic chamber; they call this an acceptable margin of error. It is a research prototype, not a certified test range, so do not rely on it for formal certification.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The paper reports an RMSE of about 1.5 dB against the datasheet at 750 MHz in the horizontal plane, and the whole system costs around 989 dollars in parts where the commercial unit it compares against is around 18,560 dollars. If you were building this, what frequency would you measure first?
Alex Kana-Chuctaya and Alexander Hilario-Tacuri
Both researchers are at the Universidad Nacional de San Agustin de Arequipa in Peru. They published this work in HardwareX in 2025 to provide an open, low-cost alternative to commercial antenna test systems that cost over 18,000 dollars and are out of reach for most university labs.
Keep building — related projects
Same category or platform, picked by how close they are to this build.
FULL CADA 300-dollar kit turns a decades-old lab microscope into an automated scanning system
ScienceFor intermediate builders
FULL CADAllsky: a Raspberry Pi camera in a weatherproof dome that films the whole night sky by itself
ScienceFor intermediate builders
FULL CADYou can build the rig that gives every bee in the hive its own barcode
ScienceFor advanced builders
FULL CADYou can print a motorised lab microscope at home — and it is already used in malaria research
ScienceFor advanced builders
FULL CADYou can build an open-source algae photobioreactor with a built-in fluorometer
ScienceFor advanced builders
FULL CADA fluorescence microscope for under 500 dollars, and it keeps up with an Olympus
ScienceFor advanced builders
DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM18d agoedited
Practical notes from our verification: the HardwareX article is the primary source, and all files are hosted on the Open Science Framework at osf.io/kbm3f, not on GitHub. The bladeRF 2.0 micro xA4 is the single biggest line in the paper's bill of materials, at about 560 dollars, more than half of the total, so its availability decides when you can start. The antenna supports are 3D printed in PETG and the STL files are published. Angle tracking is handled in software: separate threads for transmitting, receiving, rotation and synchronisation are coordinated by the main program, and an MOC70T3 optocoupler serves as the reference sensor that calibrates the zero-degree position. Test that homing step carefully before running a full pattern capture. The paper validated the system at 750 MHz and 2600 MHz, in both horizontal and vertical planes, outside an anechoic chamber. The documentation is thorough, but it is written for someone who already understands antenna measurement and SDR, not for someone learning RF from scratch. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.