Radiation performance enhancement of an ultra wide band antenna using metamaterial band-pass filter

Abstract

In this paper, a metamaterial structure based on Frequency Selective Surface (FSS) cell is proposed to achieve an isotropic band-pass filtering response. This filter consists of a planar layer formed by a 3×3 metamaterials cell array with transmittive filtering behavior at 3.5 GHz. This design with 45 mm × 45 mm dimension is then integrated in close proximity at distance of 10 mm with an Ultra Wide Band (UWB) antenna to enhance it’ s performances around a 3.5 GHz operating frequency. Simulation results ensure that filter geometry provides the advantage of polarization independency and also exhibits the angular stability up to 45◦ for both Transverse Electric (TE) and Transverse magnetic (TM) modes. More importantly, enhancement in antenna radiation pattern characteristics is illustrated when the planar FSS layer is integrated at a small distance from the radiator. Moreover, antenna gain was improved to 3.22 dBi, adaptation of antenna port (S11) was increased to -53.26 dB and antenna bandwidth reduction to 1.7 GHz is also detected. All these performances make the proposed design as a good choice used to shield signals in UWB wireless applications especially for connected object in 5G.