Design and Analysis of Microstrip Patch Antenna at 2.3 GHz Frequency for S-Band Applications

In this study, a compact microstrip patch antenna design for S-band ($2-4 \mathrm{GHz}$) applications operating at a center frequency of 2.3 GHz is presented. The design and analysis process is carried out using CST Studio Suite electromagnetic simulation software. The antenna is positioned on FR4 dielectric substrate ($\varepsilon_{\mathrm{r}}=4.3, h=1.6 \mathrm{~mm}$), fed by microstrip line and optimized with dimensions of $75.75 \times$ $57.13 \times 1.6 \mathrm{~mm}^{3}$. Simulation results show that the antenna exhibits an extremely low return loss of -56.631 dB at the targeted resonant frequency, indicating excellent impedance matching. The antenna has a gain of 2.609 dBi and a directivity of 6.646 dBi. Polar radiation pattern analysis revealed that the main lobe is located at 3°, the $3 d B$ angular width is 97.1°, and the side lobe level is suppressed by -11.6 dB. These results demonstrate the antenna’s ability to concentrate energy in certain directions and minimize radiation in undesired directions. The obtained performance parameters show that the antenna offers an efficient, low-loss and directional solution for S-band applications, especially in areas such as satellite communications, radar, wireless communication systems Wi-Fi, Bluetooth. Based on these results, the proposed design is a strong candidate for potential application scenarios at both academic and industrial levels.