Miniaturized circular patch antenna with metamaterial loading

In this contribution, we present a possible implementation of a miniaturized circular patch antenna with metamaterial loading. In previous theoretical investigations we have already shown that it is possible to excite a resonant radiating mode in a circular patch by using an inhomogeneous substrate made of the combination of a regular dielectric and a metamaterial exhibiting a negative real part of the permeability. While in our previous works we have considered the metamaterial as an ideal isotropic material described by a Lorentz-like dispersion, here we propose a possible implementation of the same structure, employing proper resonant inclusions. A theoretical cavity-model analysis allows determining qualitatively the expected near field distribution of the antenna at its resonance and therefore optimizing the location and orientation of the inclusions. The final layout has been simulated through a full-wave commercial code and the resulting matching and radiation features, in good agreement with our previous theoretical investigations, demonstrate the possibility of realizing a resonant sub-wavelength patch exhibiting good matching and radiating features.