Open-source QuadRF phased-array radio can visualize 5GHz WiFi through walls and track drones using Raspberry Pi hardware

QuadRF is a handheld phased-array radio built around a Raspberry Pi 5 and FPGA board, using precise timing, beamforming, and signal processing to detect drones and visualize 4.9GHz-6GHz RF activity. Its software can stream and decode radio signals, enabling uses such as WiFi traffic analysis when paired with more powerful computers.

The project shows how capabilities once limited to governments or specialized labs are becoming accessible through open-source hardware and software-defined radio. As phased-array systems get cheaper and more modular, they could accelerate legitimate research and security testing while raising new privacy and surveillance concerns.