Pi-Radio v1: Calibration techniques to enable fully-digital beamforming at 60 GHz

The Pi-Radio v1 software-defined radio (SDR) platform incorporates a 4-channel fully-digital transceiver board that operates in the 57–64 GHz band and connects to the powerful Xilinx RFSoC-based ZCU111 evaluation board. This paper illustrates various calibration procedures that have been implemented to avoid relying on expensive laboratory equipment and infrastructure like spectrum analyzers, signal generators, or even anechoic chambers. We conclude this paper with a demonstration of beamforming enabled through geometrically determined beamforming weights, thereby demonstrating that the SDR nodes have been calibrated correctly.