A Concave Circular Brick-Shaped Metamaterial-Inspired Superstrate Based High-Gain Microstrip Patch Antenna for Wideband Applications

In this manuscript, a highly effective metamaterial (MM) superstrate is presented, which is intended to significantly enhance the gain (G) of a partial ground wideband microstrip patch antenna (PG-WMPA) in the measured operating frequency band (OFB) of 3.8 GHz-10.65 GHz for satellite communications, 5 G networks, and radar systems. A $3 \times 3$ array of the MM superstrate (MMS), sized $0.93 \lambda_{g} \times 0.93 \lambda_{g}$, is formed using MM unit-cells with dimensions of $0.3 \lambda_{g} \times 0.3 \lambda_{g}$. Each unitcell incorporates an innovative integrated concave circular brick (ICCB) shaped along with horizontal and vertical rectangular slots. Using the proposed ICCB-shaped unit-cells, a $3 \times 3$ array of MMS is designed on an RT/Duroid 5880 substrate and positioned 14.5 mm above the PG-WMPA. The proposed MMS shows the negative intrinsic material properties in the wide frequency band from $5.8 \mathrm{GHz}-10.0 \mathrm{GHz}$. As a result of successfully implementing the proposed ICCB-shaped MMS, the measured average gain, $G_{a v}$ of the PG-WMPA increased from 4.49 dBi to10.45 $d B i$ and provided a bi-directional radiation pattern. Further, a prototype of the proposed PG-WMPA with ICCB-shaped MMS has been developed and measured to verify the genuineness of the simulated results.