An open-source 240-antenna array to bounce signals off the Moon

A new open-source hardware project called QuadRF is democratizing access to large-scale phased array technology with an affordable, modular software-defined radio (SDR) tile. Priced between $49 and $99, each compact 13cm tile packs four antennas, a Lattice ECP5 FPGA, and operates in the 4.9-6.0 GHz C-band with full-duplex communication. With 40 MHz of bandwidth per antenna, 1 Watt of transmit power, and remarkably low latency under 1 millisecond, the tile is engineered to be a fundamental building block. Its design allows dozens or even hundreds of tiles to be synchronized into a single, massive array, such as the viral concept of a 240-antenna system capable of performing moonbounce (Earth-Moon-Earth) communications, a feat traditionally reserved for well-funded institutions.

This approach transforms complex radio astronomy and advanced wireless research into a scalable, community-driven endeavor. As a standalone unit, the QuadRF tile functions as a capable 4x4 MIMO SDR for general-purpose experimentation, direction-finding, or RF exploration. When arrayed, the combined system's gain and directivity open doors to significant projects: establishing open-source cellular networks (4G/5G), creating high-definition drone communication links, and enabling precise robotics control. By drastically reducing the cost and complexity barrier, QuadRF empowers researchers, universities, and amateur enthusiasts to experiment with beamforming and large-aperture systems that were previously inaccessible, accelerating innovation in both telecommunications and citizen science.