Comparative Performance Assessment of Different Rectangular Microstrip Patch Antenna Array Configurations at 28GHz for 5G Wireless Applications

Abstract

Advancements in wireless communication systems needs a low cost, minimal weight, and low-profile antenna arrays that are capable of providing high performance over a wide fre quency band. With this regard, the patch antenna arrays are preferred to overcome some of the challenging requirements of the 5G mm-wave communication systems. However, the bandwidth of microstrip patch antenna (MSPA) is narrow; its directivity, gain, and radiation efficiency are low. In addition, integrating a large number of patch antenna in the form of an array leads to increased mutual coupling between the radiating elements that distorts the field pattern, reduces radiation efficiency, and directivity of the antenna. Attempting to improve the performance of rectangular MSPA in terms of the direc tivity, radiation efficiency, and bandwidth; various design techniques have been reported in the scientific literature. These are: cutting a resonant slot inside the patch, deflected ground plane, modifying the physical geometer of the patch, by using changing array ele ments and substrate thickness. However, their design considerations were to achieve good performance only in terms of one or two performance metrics. Also, the main focus of the studies was only for single element and linear rectangular MSPA arrays, and less study has been carried out to explore planar array configuration at 28GHz using large number of array elements. Therefore, in this study the design and comparative performance assessment of different size of linear and planar rectangular MSPA array configurations have been pro posed and simulated using CST antenna simulator. Besides, in order to boost some of the performance metrics; inset-feed and quarter-wavelength impedance matching techniques, and tuning the parameters of the antenna have been used. The simulation results show that directivity of the proposed single element, 2x1, 4x1, 2x2, 4x4, and 8x8 rectangular MSPA arrays are 7.41dBi, 9.451dBi, 11.2dBi, 11.12dBi, 15.80dBi, 19.31dBi; the return losses are -20.24dB, -19.88dB, -27.42dB, -32.688dB, - 33.15dB, -17.75dB. Moreover, the radiation efficiency is more than 94.95% for 1D MSPA arrays and 79% for 2D MSPA arrays. From simulated antenna structures it has been ob served that, tuning the dimension of width of the patch, microstrip feeder line, ground plane, and inset gap has direct effect on the input impedance, bandwidth, directivity, and radiation efficiency of the antenna. The overall extensive comparative study of different antenna array structures using simulation shows that there is no single best design in terms of all the performance parameters of the antenna. Hence, there is a design trade-off that should be considered depending on the requirements of a particular application.