Patch antenna miniaturization using artificial magneto-dielectric metasubstrate

Effective antenna miniaturization is a challenging problem due to the inevitable trade-off between size and performance of the antenna. Increasing the effective medium parameters, permittivity and permeability, results in antenna size reduction. Note that the use of dielectric materials as the antenna substrate with high permittivity is to reduce size but at the same time the efficiency and the bandwidth are significantly reduced. Alternatively, therefore, one can use magneto-dielectric material (MDM) procuring an antenna size reducing with a sufficient bandwidth. MDMs are materials with both the permittivity and permeability greater than unity (ε_eff >; 1, μ_eff >;1). Recently, the use of MDM, whether real or meta, has been attracted a large amount of attentions. The real materials, magnetic nanoparticles, namely nickel and cobalt, require complex fabrication technology and hence are relatively expensive. Moreover, it is difficult to achieve low loss for these materials above a few GHz. Another possible way to design MDMs, involves using periodic structures composed of metallic and dielectric or magnetic materials. Nowadays, researchers devote to antenna miniaturization using artificial magneto-dielectric materials as a substrate, called artificial magneto-dielectric metasubstrate (AMDM). AMDMs are used as an antenna substrate of low profile antennas to reduce the size of antennas while maintaining good performance.In this paper, artificial magneto-dielectric metamaterial is used as a substrate in design of miniaturized patch antenna. The new spiral loop resonator is a generic inclusion for design of AMDS with desired properties. The advantages of the AMDM, in comparison with dielectric and magnetic substrates, are reported.