A Compact and Efficient S-band Rectangular Microstrip Antenna for Maritime Radar Applications

The growing demand for compact, high-performance antennas in maritime radar systems drives the need for designs that simultaneously optimize bandwidth, efficiency, and form factor. This paper presents a novel S-band (2–4 GHz) rectangular microstrip antenna featuring a serrated and perforated ground plane, engineered to overcome the inherent bandwidth-size trade-off in conventional designs. The antenna is implemented on a cost-effective FR4 substrate (ε _r = 4.3, h = 1.3 mm, tanδ = 0.025) with a total size of 0.31λ × 0.31λ × 0.01λ and utilizes a 50-Ω inset feedline for excitation. Simulations are performed using CST Microwave Studio Suite (2024) to evaluate the antenna’s design and performance metrics. The simulation results reveal outstanding performance, including a reflection coefficient (S₁₁) of -60.78464 dB, a wide operational bandwidth of 1.605059 GHz (2.054032–3.659709 GHz), and a radiation efficiency of 83.77%. The antenna exhibits a voltage standing wave ratio (VSWR) of 1.003433, with a gain of 1.76 dBi and directivity of 2.53 dBi, confirming efficient radiation performance. These results contribute to the advancement of compact maritime antennas by balancing miniaturization and high-frequency performance. The study highlights the effectiveness of geometric ground plane modifications for bandwidth enhancement, providing a viable solution for modern radar systems in challenging marine environments. Future work will focus on experimental validation and scalability to other frequency bands.