Hybrid Multi-Objective Optimized U-Slot Microstrip Patch Antenna with Defected Ground Structure for 28-GHz 5G Applications

Abstract

Fifth-generation (5G) mobile communication systems are rapidly changing, especially in the millimeter-wave (mmWave) frequency range. Future high-quality data rates and low latency require completely new types of antennas with a greater degree of compactness, gain, and relative bandwidth than traditional mobile communication antennas. Microstrip patch antennas (MPAs) have been investigated extensively for use in 5G systems because they are planar, easy to manufacture, and compatible with computer chips. Existing microstrip patch antennas experience a lot of difficulties in providing enough bandwidth for 5G applications, good enough radiation efficiency, and decreased amounts of gain at higher operating frequencies. New techniques being used to enhance performance for 5G mmWave applications include the use of slots, defected ground structures (DGS), integration of metasurfaces, and arrays. This research uses a fully parametrically optimized microstrip patch antenna for 28 GHz 5G systems using a hybrid multi-objective optimization approach integrated with full-wave electromagnetic simulation. A U-slot radiator design is used in conjunction with a defected ground structure to improve the impedance bandwidth and radiation performance while maintaining a compact overall geometry. The antenna has been optimized for gain, bandwidth, and radiation efficiency using simulation-driven parametric tuning and evolutionary optimization. The design is validated through cross-solver consistency and comparison with recent 28-GHz antenna structures. CST Microwave Studio and ANSYS HFSS simulations produced peak gains of 9.2 dBi, a fractional bandwidth in excess of 24%, and a reflection coefficient less than −30 dB at resonance. Comparative evaluation with recent 5G antenna designs confirms improved gain-bandwidth trade-off and compactness. The proposed methodology establishes a scalable framework for mmWave antenna synthesis in massive MIMO systems, small-cell base stations, and next-generation wireless platforms.