Design and analysis of frequency selective surface embedded broadband high gain miniaturized antenna

Incorporating the better impedance matching capability of planar curved radiating patch, a miniaturized broadband planar antenna has been designed, analyzed, and integrated with frequency selective surface (FSS) to accomplish higher gain for various short-range and long-range modern wireless communication applications. Physical and electrical volume of the presented antenna is 25 x 20 x 1.6 mm3$$ {\mathrm{mm}}<^>3 $$ and 0.25 lambda 0$$ {\lambda}_0 $$ x 0.20 lambda 0$$ {\lambda}_0 $$ x 0.016 lambda 0$$ {\lambda}_0 $$, respectively. The proposed radiating patch is constructed from a conventional rectangular patch by transforming the upper side of the patch into a semi-circular shape and the lower side of the patch into a staircase-like shape. Measured outcomes of the designed antenna show a very large operating bandwidth of 19.8 GHz (3-22.8 GHz) with a fractional bandwidth (FBW) of 153.5% and bandwidth dimension ratio (BDR) of 3070. An equivalent circuit model (ECM) of the proposed antenna is developed using an advanced design system (ADS) circuit simulator. The frequency responses of the ECM are compared with the simulation done by CST Microwave Studio Suite software and measurement results, which show good agreement. An FSS structure with stop band from 2-28 GHz is positioned beneath the proposed antenna at optimal position (27 mm below the antenna) to enhance the gain up to 8.9 dBi. The presented antenna and FSS are fabricated on FR4 substrate and experimentally verified using standard microwave measurement setup. Measured outcomes of the designed antenna show a very large operating bandwidth of 19.8 GHz (3-22.8 GHz) with a fractional bandwidth (FBW) of 153.5% and bandwidth dimension ratio (BDR) of 3070. An FSS structure with stop band from 2 to 28 GHz is positioned beneath the proposed antenna at optimal position to enhance the gain up to 8.9 dBi. image