Two-Dimensional Positioning and Phase Synchronization System for Drone-Based Spatially Reconfigurable Phased Array

This paper presents a 2-D wireless ultrasound-microwave phase synchronization (UMPS) system for a Unmanned Aerial Vehicle (UAV) -based phased array. It is extended from its 1-D counterpart [6]. The UMPS system consists of multiple non-connected modules that operate in a leader-follower scheme for positioning and phase synchronization. The UMPS includes multiple non-connected modules that follow a leader-follower scheme for positioning and phase synchronization. The leader is the only reference point, to which followers locate their relative positions by Time-of-Flight (ToF) of ultrasound calibrated with microwave signal and synchronize its phase by on-board phase shifters. With a proper phase compensation, the UMPS modules can form a phased array with a 2D-variable spatial arrangement of antenna elements. In this work, the 2D-prototype UMPS exhibits a root-mean-square (RMS) positioning error at 9 mm and a 5.6° RMS phase error for synchronizing a 433 MHz continuous wave RF signal, which is satisfactory for forming a UAV-based phased array.