Compact GNSS Metasurface-Inspired Cavity Antennas

This letter presents an innovative circularly polarized compact cavity antenna based on metasurfaces; the proposed design is explained starting from a linearly polarized antenna based on similar concepts. The main objective is to cover three different GNSS systems, namely Galileo E1, GLONASS G1, and GPS L1, with a single antenna embedded in a metallic cavity. The aperture dimension is set to 0.26λ0 × 0.26λ0, with a central frequency of 1578 MHz. Loading the aperture with a metasurface allows an efficient radiation within such a small aperture size. Our experimental results are in a very good agreement with the simulations, with an axial ratio lower than 2 dB between 1540 and 1655 MHz.