Miniaturized Array Antenna Using Artificial Magnetic Materials for Satellite-Based AIS System
The ground-based automatic identification system (AIS) is a coastal tracking and messaging system used by vessels for maritime traffic monitoring. The European SAT-AIS initiative aims at providing a space-based complementary system to extend the range of the existing AIS to high seas via very high frequency (VHF) satellite constellation. The AIS Miniaturized Antenna (AISMAN) activity concentrates on the development of a VHF array antenna for minisatellite platforms in low Earth orbit. Array element volume minimization and mass reduction are considered performance drivers due to the in-orbit array deployment and satellite mass requirements. Artificial magnetic materials (AMMs) have been chosen as design concept of the baseline array element due to the significant size reduction they can offer. Further technical solutions, such as slotted ground plane, combined with AMM, have allowed for an outstanding profile reduction, while preserving high radiation efficiency and low back radiation. Innovative testing methodologies have been specifically developed to handle truncation errors and echo signals while performing radiation pattern measurement of the array on a full-scale mockup platform in a hemispherical automotive near field (NF) range. This paper discusses the design of array elements, from breadboard to engineering model (TRL4), manufacturing and validation campaigns at single element and array level.