THz technology has piqued the interest of many people worldwide. For THz communication to radiate and detect high-frequency waves, THz antennas are required. In order to send and receive electromagnetic (EM) waves in the developing THz system, THz antennas that are small, have a wideband spectrum, and can handle much higher information rates are necessary. This chapter designs a rectangular THz patch antenna to mimic the patch antenna’s performance. We observe the antenna’s poor performance and enhance it by implementing the metamaterial structure. We incorporate the rectangular patch with a superstate model and simulate the designed structure. We further optimize the rectangular tube slot for various turns and analyze the patch antenna characteristics. The metamaterial patch antenna with four turns produces excellent antenna performance, such as −48.65 dB return loss (RL), 1.05 VSWR, and 8.07 dBi directivity at 2.463 THz frequency. The proposed metamaterial antenna is applicable for high-speed communication and various THz devices.