Seeing The World In Radio Waves With The QuadRF
Summary
Hackaday reviews QuadRF, a phase-coherent four-channel SDR for radio direction finding, pairing a Raspberry Pi 5 with an FPGA-based RF board and four patch antennas. The system supports GNU Radio and includes an RF camera that visualizes direction finding at 30 fps, capable of tracking signals like a drone, and can be scaled into larger phased arrays. The article also notes regulatory considerations for transmit-capable hardware.