This study has developed a patch antenna that operates at 28 GHz. The antenna uses three different substrate materials, each with a significantly different relative permittivity. Rogers RT5880 (antenna design-I), Arlon AD 250C (antenna design-II), and Silicon (antenna design-III) are the three substrate materials. The thickness of Rogers RT5880 is 1.527 mm, while the thickness of Arlon AD 250C is 0.85 mm, and the thickness of Silicon is 1.36 mm. These three materials have relative permittivity values of 2.2, 2.5, and 11.9, respectively. Utilizing CST Microwave Studio, the performance of the antennas is simulated, analyzed, and compared in terms of their efficiency, bandwidth, gain, and return loss, as well as VSWR. Because the substrate materials have different relative permittivity and thickness values, the results show that gain, directivity, efficiency, and bandwidth are all very different. Design-I, design-II, and design-III each produced gains and directivity of 7.47 dBi, 7.44 dBi, 6.84 dBi, 8.23 dBi, 8.18 dBi, and 7.25 dBi, respectively. Silicon had the highest efficiency of the antennas at 94.43%, compared to Rogers RT5880, which had a 90.77% efficiency, and Arlon AD 250C, which had a 90.95% efficiency. Finally, design-I has a bandwidth of 3.4 GHz, design-II has a bandwidth of 1.501 GHz, and design-III has a bandwidth of 0.435 GHz. This paper aims to reduce return loss and improve antenna gain, directivity, and bandwidth. The overall performance of this antenna is highly suitable for 5G wireless applications.