High dielectric constant EBG technology to avoid gratings lobes and scan blindness in array configurations

Abstract

High dielectric electromagnetic band gap (EBG) substrates can be used in patch antenna configurations to reduce size and mitigate substrate modes propagation with reasonable radiation efficiency values (ηrad > 0.55). Furthermore, EBG substrate structures applied in array configurations are able to avoid grating lobes and scan blindness phenomena as distance and coupling between patch antenna-radiating elements can be reduced at the same time. In this paper, a 2 × 2 array configuration using Zirconium Tin Titanate EBG substrate with high dielectric constant is presented. The array has been simulated showing 9 dB coupling reduction obtained by the inclusion of the EBG substrate in between the patch antennas placed to a distance lower than 0,5λ0. This short distance together with the coupling reduction results in a configuration which does not suffer from grating lobes and scan blindness problems, obtaining a 30º scan angle for the 2 × 2 configuration which is the maximum achievable angle due to a 2 × 2 array factor. A scan angle larger than 70º can be seen for the infinite configuration.