Miniaturisation of microstrip patch antenna using an artificial planar magneto‐dielectric meta‐substrate

Abstract

In this communication, a practically realisable artificial planar magneto-dielectric (MD) meta-substrate is proposed and investigated for microstrip patch antenna miniaturisation. The meta-substrate employs cross-coupled twisted metallic split-ring resonator ring pairs to achieve effective permeability ( μ eff ) and permittivity (e eff ) greater than that of the host dielectric which leads to antenna miniaturisation. Electromagnetic simulation and analysis of effective material parameters are performed to characterise it, which shows nearly equal enhanced effective permeability and permittivity ( μ eff ≃ e eff ) at 2.35 GHz with low loss-factor level not achievable from natural materials. An inset fed microstrip patch antenna is designed on the proposed MD meta-substrate to test and validate its performance. The performances of the miniaturised patch antenna loaded with proposed dispersive MD meta-substrate, non-dispersive homogenous MD substrate, and high-permittivity substrates (lossy and loss-free) are compared with the conventional patch antenna on host dielectric. It is found that dispersive nature of the meta-substrate plays a critical role in the antenna performance. The antenna on proposed meta-substrate occupying an overall volume of 0.250 λ 0 × 0.344 λ 0 × 0.009 λ 0 at 2.35 GHz is 74.83% miniaturised as compared with the conventional antenna on host dielectric. To ensure the practicability, the designed antenna is fabricated and measured.