Metamaterial Based Multiband Microstrip Patch Antenna with Defective Ground

In this research a dual band microstrip patch antenna, which resonates on IEEE 802.11a 2.45 GHz and 5 GHz Wi-Fi bands, is proposed. The patch is slotted at two opposite edges to obtain the dual band characteristics. The size of ground plane has been reduced and a split ring resonator has been incorporated to enhance the gain and bandwidth of the proposed antenna. Initially, the patch antenna resonates at 5.8 GHz with gain and bandwidth of 6 dBi and 290 MHz, respectively. Also, an additional resonant frequency of 2.45 GHz is generated when two slots are added at the patch's two opposing edges. This resonant frequency’s gain and impedance bandwidth are, respectively, 345 MHz and 10.5 dBi. When ground plane is reduced in size and a split ring resonator is incorporated in the ground plane, the initial resonant frequency gets shifted to 5 GHz, along with betterment in gain and impedance bandwidth at this resonant frequency. Now the designed antenna resonates at 5 GHz with 410 MHz impedance bandwidth and 6.5 dBi gain. FR-4 substrate has been selected to design this proposed antenna, with a commercially available electromagnetic simulator, HFSS.