Analysis and design optimization of Robust aperiodic micro-UAV swarm-based antenna arrays

Micro-UAV swarm-based antenna arrays provide a novel solution for high-risk radar imaging applications. These apertures lack a single point of failure by distributing their resources and sensors across multiple platforms. However, turbulence and positional errors provide a challenging operational environment when it comes to the implementation of these systems. Turbulence can limit the aperture's ability to coherently resolve a target and cause aircrafts to collide in midair if the formation is too tightly packed with closely spaced elements. This paper introduces several techniques that can reduce the effects of turbulence on the system. First, a phase compensation algorithm is presented that can eliminate the effects of turbulence on the main beam of the array. In addition, sparse antenna apertures can be used to create flight formations that reduce the probability of midair collisions. Traditional periodic apertures are insufficient because these arrays display grating lobes at wide interelement spacings. Therefore, two aperiodic array optimization methodologies are discussed that produce sparse array configurations suitable for micro-UAV formations. These sparse arrays exhibit low peak side-lobe levels without the presence of grating lobes over wide interelement spacings. By combining phase compensation with optimized sparse aircraft formations, one can achieve high radiation pattern resolution in a micro-UAV based radar imaging application.