QuadRF democratizes modern phased array technology, bringing it down to Earth in an accessible, hacker-friendly, and programmable kit. At its core, QuadRF is a modular 4×4 MIMO software-defined radio tile with an open antenna architecture. Powered by an integrated Raspberry Pi 5, it functions out of the box as a real-time RF camera, expanding SDR exploration from the traditional time and frequency domains into the spatial domain.

While a single QuadRF is a complete, fully functional phased array development platform, it is also designed from the ground up as a building block for much larger arrays. Beamforming computation is distributed across each tile’s Lattice ECP5 FPGA, meaning users can link boards together to scale into square-meter scale phased arrays, such as our open-source 240-antenna MoonRF design.

Catch Some Waves

QuadRF lets you directly explore the RF environment around you. See where signals are, the way they propagate, and how antennas and the surrounding environment interact. At 30 fps, you can map Wi-Fi devices in a room, quadcopters in the sky, or other wireless transmitters. Expanding beyond vision and LiDAR, your robots can use QuadRF to gain real-time spatial awareness of surrounding radio beacons and access points. It’s a complete, full-duplex SDR with dual polarization, and becomes a powerful tool for those looking to develop and experiment with true 4×4 MIMO and beamforming. Out of the box, it integrates directly into your existing workflow, ready to run popular frameworks like GNU Radio, SoapySDR, or your own custom RF code.

QuadRF is also a powerful diagnostic tool for engineers and hardware developers to debug their own RF products. You can use it to see exactly where a device is radiating or how signals change with an enclosure. Because QuadRF is full-duplex, it doesn’t just listen—it can also transmit probe signals to measure a spatial response. This allows users to characterize shadowing, absorption, reflections, material polarization effects, and general RF channels throughout the environment. For educators, QuadRF is a practical, hands-on teaching tool for university students learning about MIMO, phased arrays, and spatial wireless measurements.

To take this into the field, the included tripod converts into a mobile carry handle. It features an integrated smartphone holder that perfectly aligns your phone’s camera with the QuadRF array, allowing you to easily utilize augmented reality (AR) visualization on the go.

Features & Specifications

RF & Wireless Capabilities

• 4 RX / 4 TX full-duplex coherent channels.
• Operating frequency range of 4.9 – 6.0 GHz (C-Band).
• 40 MHz of bandwidth per antenna.
• 1 Watt Tx power per antenna utilizing four SiGe power amplifiers.
• Four swappable dual-polarization (RHCP and LHCP) antennas.

Compute & Processing

• Integrated Raspberry Pi 5 for onboard computation and control.
• Lattice ECP5 FPGA (LFE5U-45F-7BG256I) for distributed DSP and beamforming.
• Analog Devices MAX2850 4-channel Upconvert Mixer and MAX2851 4-channel Downconvert Mixer.
• High-throughput MIPI data path between the RF FPGA and the Linux Pi 5 host.

Connectivity, Power & Interfaces

• USB 3.0, Gigabit Ethernet, Wi-Fi, and Direct HDMI/USB support.
• Optional Mobile Pack: A separate add-on featuring a back-mountable battery bank for 21700 Lithium batteries, providing 5-6 hours of mobile use (Rx only) or 3-4 hours under 100% Tx load.

Physical Properties

• Custom 3D-printed magnetic enclosure utilizing transparent 8001 resin.
• Includes convertible desktop/mobile-carry tripod with an aligned smartphone holder for AR applications.
• Dimensions: 15 x 11 x 4 cm (5.9 x 4.3 x 1.6 inches)
• Weight:
  • QuadRF Tile + antenna: 35 g (1.2 oz)
  • QuadRF Kit with enclosure: 190 g (6.7 oz)
  • Complete kit (with all accessories, tripod, power supply): 670 g (1.48 lbs)

Software & Ecosystem

• Out-of-the-box Web RF GUI, Web Remote Desktop, and Direct Pi 5 Linux access.
• Compatible with GNU Radio, SoapySDR, and ZeroMQ.

Open Source

QuadRF uses a hybrid open model. We have open-sourced the elements where users are most likely to modify, extend, and build, while protecting the RF-core implementation that makes a low-cost 4×4 MIMO SDR tile possible.

• Software, Drivers, and Applications: The entire QuadRF software stack is 100% open-source under GPLv2/GPLv3. This includes Linux drivers, SoapySDR support, control APIs, calibration utilities, web interfaces, and example applications.
• Antenna and Array Ecosystem: The antenna and mechanical ecosystem is fully open-source under CC BY-SA 4.0. We publish the 4-element, 72-element, and 240-element FR4 antenna PCB CAD/Gerbers, OpenEMS simulation files, and MoonRF array structure CAD.
• FPGA Customization: The onboard Lattice ECP5 FPGA is unlocked and user-programmable. It can be programmed directly from the Raspberry Pi 5 using OpenOCD or through standard JTAG tools.
• Protected RF Core: The production RF-core and official factory DSP bitstreams are proprietary. However, we provide source-available RF schematics for debugging, education, and academic research.

Accessing the Files
All open-source software files and schematics are available right now. Antenna design files and simulations to be opened before the campaign completes.

• Software & Hardware Files: Access our repositories on our GitHub page.
• Documentation: Read the full setup and customization guides at moonrf.com/docs.

Interested in This Project?

You can sign up at the top of this page to be notified when the campaign launches and to receive other updates. We only send out relevant content, and you can unsubscribe at any time.