Electromagnetics-Aware Path for UAV-Based Near-Field Antenna Measurements Implemented With a High Dynamic Range SDR

An electromagnetics-aware path for drone-based near-field (NF) antenna measurements is implemented in an outdoor experimentation. This technique allows us to significantly reduce the scan duration with respect to a standard half-wavelength NF scanning, using knowledge of the antenna under test (AUT) electrical size only. The validity of our approach is corroborated with planar outdoor NF measurements performed with an untethered drone transmitting at 750 MHz. To deal with the absence of phase coherence, the phase information is retrieved from a reference antenna, while a software-defined radio (SDR) having four super-heterodyne receiving channels is used to properly sample the high-dynamic signals resulting from the large scanning surface.