A novel wide-band frequency selective surface (FSS) with integrated four port X-band (FPXB) MIMO antenna designed for wireless applications

This research reports the design analysis of four-port MIMO FPXB antenna loaded with novel Frequency-Selective-Surface (FSS). The proposed antenna is printed on Rogers RTDuroid5880 dielectric with overall size of 0.999 λ o × 0.999 λ o × 0.0.07 λ o where λ o corresponds lower cut-off frequency of 6.77GHz. A wheel-shaped stub within the hexagonal annular ring connected to tapered feedline and defected ground offers X-band bandwidth of 6.77GHz-13.60 GHz. The MIMO antenna is also integrated with 5 × 5 FSS of size 90.0 × 90.0 × 1.60 mm 3 printed on top-surface which enhances the peak-realized to 11.88 dBi at 10.0 GHz. The inherent resonant behaviors of the proposed X-band antenna is studied by subjecting Characteristics-Mode-Analysis (CMA) of 10-modes and the surface current density analysis for significant modes at 8.0 GHz, 10.0 GHz and 12.0 GHz shows the radiation performance without any input excitation. The proposed antenna is also validated by generating equivalent circuit model for single-port antenna with EM-circuit simulator generating X-band. The four-radiating elements are arranged in orthogonal sequence with interconnected ground achieving spatial-diversity. The measured diversity parameters in the measured operating bandwidth of 6.80 GHz–11.36 GHz corresponds to ECC FPXB < 0.0025, DG FPXB ≥ 9.92 dB, TARC FPXB < −4.0 dB, CCL FPXB < 0.30 b/s/Hz and MEG FPXB ≅ −3.0 dB. The MIMO FPXB antenna is also subjected to bending analysis at angles of 0 ° , 10 ° , 20 ° , 30 ° and 45 ° with the corresponding −10.0 dB bandwidth including X-band. The SAR FPXB values are also calculated at 7.50 GHz with a value of 0.0044 W K −1 g −1 and at 9.0GHz with a value of 0.0754 W/Kg. The far-field 2D radiation patterns are also stable in the E-plane and H-plane with low values of cross-polarization at 7.50 GHz and 11.0 GHz. The multi-feature MIMO FPXB antenna loaded with FSS FPXB is a good candidate for X-band applications.