Microstrip Patch Antenna Arrays for 5G IoT and Smart Communication Systems: A Literature Review

Microstrip patch antenna (MPA) arrays have become crucial enablers for 5G networks, the Internet of Things (IoT), and smart communication systems. This literature review surveys advances over the past five years in MPA array designs, focusing on both performance metrics (gain, bandwidth, efficiency) and novel design techniques (substrate materials, metamaterials, reconfigurability). We compare a range of 5G-oriented MPA arrays – from sub-6 GHz wideband IoT antennas to millimeter-wave beamforming arrays – and discuss how each achieves improvements in gain and bandwidth while maintaining efficiency. Metamaterial integration and defected ground structures have yielded compact, broadband arrays with high efficiency, whereas reconfigurable designs enable multi-band or beam-steering capabilities. A comparative analysis of recent 5G MPA array designs is presented, highlighting trade-offs in gain vs. bandwidth and the impact of materials and geometries. Key trends such as the move toward higher frequencies (mmWave), MIMO and beamforming integration, and multi-functional antenna designs are identified. We also outline challenges like efficiency degradation at mmWave, mutual coupling in dense arrays, and fabrication complexity, and we highlight future research directions including intelligent surfaces and 6G-ready antenna technologies. The findings underscore that MPA arrays, enhanced by advanced materials and design techniques, will continue to play a pivotal role in 5G IoT and beyond.