QuadRF is a 4×4 MIMO software-defined radio (SDR) tile powered by a Raspberry Pi 5 SBC that functions as a real-time RF camera, allowing users to visualize radio signals in their environment using a phone or computer running an augmented reality app.
QuadRF measures differences in signal arrival time using four coherent antennas and renders a live RF overlay directly on your phone or laptop at 30 FPS, letting you see RF signals from Wi-Fi devices, wireless cameras, smartphones, drones, beacons, and lab transmitters.
QuadRF specifications:
- Compute & Signal Processing
- Raspberry Pi 5 SBC for onboard computation and control.
- Lattice ECP5 FPGA (LFE5U-45F-7BG256I) for distributed DSP and beamforming.
- Analog Devices MAX2850 (Upconvert) & MAX2851 (Downconvert) Mixers.
- 5.6 Gbit/sec MIPI data path between the RF FPGA and the Pi 5
- Direct local processing on Pi 5 or network streaming for external processing.
- RF & Wireless
- 4x Rx / 4x Tx full-duplex all-digital signal chains.
- Frequency range – 4.9 – 6.0 GHz (C-Band).
- Up to 40 MHz instantaneous bandwidth per antenna.
- Up to 1W transmit power per antenna.
- 4x swappable dual-polarization (RHCP and LHCP) antennas.
- Interfaces
- Video Output – Micro HDMI port
- Networking – Gigabit Ethernet and Wi-Fi
- USB – USB 3.0 host interface
- Power Supply
- 5V DC via USB-C port
- Optional Mobile Expansion Pack with back-mounted battery bank for 21700 Lithium batteries, providing 5-6 hours of mobile use (Rx only) or 3-4 hours under 100% Tx load.
- Dimensions – 15 cm x 11 cm x 4 cm
- Weight
- QuadRF Tile + antenna – ~ 35 grams
- QuadRF Kit with enclosure – ~ 190 grams
- Complete kit with accessories: ~ 670 grams
The complete kit includes the QuadRF Tile, a custom magnetic enclosure with clear front panel, four swappable dual-polarization antennas, a Raspberry Pi 5, a cooling fan, a desktop tripod/mobile carry with smartphone mount for AR visualization, a 27W USB PD power supply, various cables and connectors, and a microSD Card preloaded with the software.
The software is 100% open-source, released under a GPLv2 license, and includes a WebRF GUI (http://quadrf/), drivers, Web Remote Desktop, and direct access to Linux (apparently DietPi, based on the screenshot below) on the Raspberry Pi 5. The solution is also compatible with GNU Radio, SoapySDR, and ZeroMQ. The AR stream works on iOS, Android, or desktop. You’ll also find the software on GitHub, and their antenna design files and simulations will be released soon before the crowdfunding campaign completes. You can also check out the documentation on the MoonRF website.
The hexagonal, bee-nest-like design is not just for aesthetics, and multiple QuadRF tiles can be mounted on the company’s open-source interconnect structures to create much larger and more powerful phased arrays. This enables people with an amateur radio license to bounce signals off the Moon (Earth-Moon-Earth communication), construct a radio telescope to map the Milky Way in the C-band, develop long-range spatial mesh networks, communicate with Low-Earth Orbit (LEO) satellites, or experiment with new mobile RF platforms. A DIY build guide will be provided soon.
Scale RF has just launched the QuadRF on Crowd Supply with a $100,000 funding target. Rewards start at $499 for a QuadRF Kit, and the optional Mobile Expansion Pack adds $159. Finally, the $594 QuadRF Six-Pack features six PCBAs for phased-array research and scalable deployments and comes with seven MIPI FPC cables for daisy-chaining. Shipping is free to the US and adds $12 to the rest of the world. Backers should expect their rewards to be shipped by the end of September 2026, except for the “Six-Pack” bundle scheduled for January 2027.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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