Applications of artificial dielectric layers for the design of planar integrated antennas

In this paper, we present an overview of our recent works on artificial dielectric layers (ADLs), used to enhance the radiation efficiency of planar printed antennas and arrays. The artificial material is realized by introducing planar sub-resonant metallic inclusions in a host material. This allows to enhance the permittivity of the host medium, which is characterized by high anisotropy. An analytical method has been developed to model the ADLs, valid for arbitrary number of layers and generic illumination. After a general description of this method, two design examples are presented. The first utilizes a single ADL slab as a superstrate of an on-chip double slot antenna operating at 300 GHz. Simulated and measured results show an improvement of the antenna gain and overall efficiency of about 2 dB. The second example exploits the use of the ADLs for the design of wideband, wide-scan planar phased arrays. A connected-slot array is loaded with an ADL superstate, to achieve wide-scan capability, up to 50 degrees in all azimuth planes, over an octave bandwidth.