The main goal is to enhance the capacity of the graphene-based patch antenna, hence the reliability of the wireless communication system. Graphene-based patch antennas have been presented for future 6G technology covering the 1–3 THz band for wireless communication service. These graphene-based patch antennas operate in dual bands at 1.52 and 2.31 THz, which is required for 6G technology wireless communication services. Different substrate materials are analyzed, and the properties of graphene material are investigated throughout the design of the antennas. Various substrate material antenna miniaturization and bandwidth improvement techniques are exploited to obtain the optimum antenna for 6G wireless communication. The simulation result shows a bandwidth of 193.7 and 113.4 GHz with return losses of − 15.22 dB and − 38.92 dB, directivity of 1.99 dBi and 4.21 dBi. The results of optimized 6G wireless communication were achieved. The Finite Integration Technique (FIT) of CST Microwave Studio Suite 2018 was used to analyze the antenna parameters.