Densely Coupled, Super-Realized Gain Printed Dipole Array With Defected Ground Structures

Super-directive antenna arrays (SDAAs), conventionally designed to achieve exceptional directivity through mutual coupling, face an inherent drawback regarding their high impedance mismatch. Despite their high directivity, the considerable decline in the mismatch efficiency, which is more pronounced for a higher number of elements, has historically undermined the practical applications of such arrays. To address this limitation, our study underscores the critical necessity of striking a delicate balance between directivity and impedance mismatch efficiency in SDAAs to maintain high realized gain achieved by multi-parameter optimization. In this context, a four-element thin-wire dipole array is initially optimized using a multi-parameter differential evolution (DE) algorithm. After successfully applying this optimization via full-wave electromagnetic analysis software, we design and analyze printed versions of the optimized array. After attaining the targeted realized gain, the antenna undergoes bandwidth and sensitivity analysis, leading to fabrication and experimental verification. Consequently, both simulation and experimental results are closely matched; thus, a compact wideband printed dipole antenna array with a realized gain value of 9.5 dBi, accompanied by an exceptionally high total efficiency as 85.3%, is introduced to the literature for dense array applications, such as massive multiple-input multiple-output (MIMO), significantly enhancing the performance and feasibility of future wireless communication technologies.