In today's fast-changing information technology, there has been an uptick in demand for wireless applications, which has impacted antenna design. In wireless applications, there is a place for a wide variety of antenna types, including array antennas, microstrip patch antennas, wire antennas, aperture antennas, reflector antennas, and lens antennas. This research shows the simulation of an S-band microstrip patch antenna planned for future wireless applications. FR-4 (lossy) and Rogers RT5880 (lossy) were the two substrate materials modeled in these simulations. These materials have thicknesses of 2.94 millimeter, and their dielectric constants are 2.2 and 4.4, respectively—thicknesses of 0.077 millimeter. Using the CST software, different antenna designs were developed and independently compared. Within the frequency range of 3.5 GHz, the modeling results for the FR-4 substrate indicate the following parameters: return loss of -17.072 dB, VSWR of 1.3294, the bandwidth of 120.9 MHz, gain of 3.321 dBi, directivity of 7.57 dBi, and efficiency of 43.88%. At the same frequency, the findings for Rogers RT5880 substrates provide a return loss of -13.772 dB, a VSWR of 1.5152, a bandwidth of 23.4 MHz, a gain of 7.55 dBi, a directivity of 8.43 dBi, and an efficiency of 89.56%. This research aimed to reduce the return loss, increase gain directivity, and improve antenna efficiency, which plays a very important role in wireless applications (especially in WLANs and Mobile Phones).