Sub-terahertz (THz) technology, 100GHz to 1THz, is expected to deliver exceptional data rates for 6G wireless communication, especially for the Internet of Things (IoT) and medical applications. However, THz waves suffers from significant attenuation, due to the absorption of water and oxygen molecules demanding wideband and high gain antenna. To address these challenges, this thesis presents the design and optimization of metamaterial(MTM)-DGS hybrid fed array. A comparative analysis of optimization algorithms CMA-ES, PSO, GA, and TR is performed and CMA-ES outperforms. Then, CMA-ES-based 10 antennas was designed, the effective one used as a reference for the novel 2×2 hybrid array. To analyze and justify the performance of this design, 1×2 and 1×4 series and parallel-fed array have been proposed. CMA-ES optimized techniques DGS and MTM are combined with parasitic patch to enhance the performance.The design and simulation was carried out in CST-MWS and MATLAB, Rogers RT Duroid 5880 used as substrate. The hybrid array antenna has overall sizes of 2.37 mm×3.22 mm× 0.05 mm. Simulation results, for the 2×2 hybrid, with DGS, parasitic, and metamaterial (proposed) achieved a corresponding return loss and bandwidth of -16.88 dB, -28 dB, -32 dB and -72.28 dB, and bandwidth 17 GHz, 17.2 GHz, 19.5, and 25.7 GHz. The 1×4 Series fed array achieved a return loss of -20 dB and bandwidth of 5.6 GHz and 5.1 GHz with gain 11.66 dB. The 1×4 parallel-fed array achieved a return loss of -41.14 dB, -24.823 dB, and -26.54 dB with, bandwidth 13.5GHz, 10.76 GHz and 13.69 GHz and gain of 8.91 dB. The 2×2 hybrid fed array outperforms the series and parallel fed arrays in return loss with improvements of 3.2 and 1.75 times, and bandwidth 4 times of the series fed and 1.25 times over the parallel at 150 GHz operating frequency. This improved performance and compact size makes it suitable for sub-THz 6G highfrequency applications. Keyword: DGS, Bandwidth, Gain, Hybrid-fed array, MTM, Optimization, Parallel –fed, Series-fed array, Sub-THz, 6G