Optimization of metallic bi-periodic photonic crystals application to compact directive antennas

Abstract

This paper presents a theoretical, numerical and experimental study for the design of a three-dimensional directive antenna for microwave telecommunications (KU-band: 12-18 GHz) applications. The presented structure consists of a stack of 6 metallic crossed grids above a ground plane, which is potentially capable to replace parabolic antennas, because it is much more compact than classical solutions and uses a single patch as feeding device. Such structure acts as a metallic photonic crystal at the band edge or as an ultra-refractive metamaterial. A numerical 3D code computing the diffraction by metallic bi-periodic gratings, and a fast layer-by-layer approach, allows to model and to optimize this kind of antennas. Especially, it is reported how both directivity and frequency bandwidth can be improved simultaneously. Numerical results are confirmed by experiments in an anechoic chamber.