This study presents the design and analysis of a three-element cylindrical conformal microstrip patch array antenna that exploits the inherent advantages of cylindrical geometries benefits that are often unattainable with traditional planar antenna configurations. Each array element consists of a rectangular microstrip patch excited by a microstrip line, specifically optimized to resonate at a frequency of 5.3 GHz. A central feature of the proposed design is the integration of a dumbbell-shaped Defected Ground Structure (DGS), strategically employed to suppress mutual coupling effects between the adjacent antenna elements. The inclusion of the DGS structure leads to a notable reduction in mutual coupling measured to be approximately 15 dB without compromising the integrity of the radiation characteristics in both the E-plane and H-plane. Comprehensive simulations of the surface wave distribution further confirm the role of the DGS in diminishing surface wave propagation, thereby enhancing the isolation between elements. Beyond its electromagnetic performance, the antenna design offers several practical advantages, including ease of fabrication, mechanical flexibility, and a compact, low-profile form factor that makes it suitable for integration into conformal platforms such as aircraft fuselages or wearable systems. The results indicate that the proposed antenna structure not only achieves efficient inter-element isolation but also maintains desirable radiation properties, marking it as a promising candidate for modern wireless and radar communication applications requiring compact, conformal, and high-performance antenna arrays.