Design and Performance Analysis of Microstrip Patch Antenna with Optimum Parameters for S band Applications

Circularly polarized antennas are widely utilized in today's wireless communication system due to their resistance to multipath distortion and polarization loss. With the increasing demand for satellite communication, the need for broadening the S band of satellite frequency in the communication sector has expanded, and the usage of S band has become more common. The proposed antenna design features a circular patch and a circular slot in ground plane. Due to its simplicity and ease of application, the defects in the ground are employed to create circular polarization and this technique is known as Defected Ground Structure (DGS) technique. The slotting technique of a microstrip antenna has benefits such as reduced profile, ease of manufacture, ease of feeding, ease of integration into the system, and, most importantly, increased gain. In this work, a microstrip patch antenna with a circular patch radiating element and a microstrip line feeding mechanism is proposed. Design and analysis of circular patch antenna has been done by using CST Microwave Studio Software. The antenna's dimensions are 25mm×25mm×1.6mm. The antenna is made of 1.6mm thick FR-4 lossy substrate, which has dielectric constant 4.3. The 3-dB axial ratio (AR) Bandwidth and Impedance Bandwidth (IBW) of the proposed antenna is 39.66 % and 4.72 % at operating frequency at 2.53 GHz respectively. The proposed antenna has S11 (return loss) of -36.27 dB and -22.51 dB at 2.53 GHz and 4.31 GHz respectively. The maximum realized gain in the boresight direction and voltage standing wave ratio is 3.50 dB and 1.03 respectively, is achieved at operating frequency.