Performance Analysis of Microstrip Antenna Array with Semi-elliptical Slotted Rectangular Patch and Ground Structure at 28GHz for Wideband Communication Systems

Abstract

The fifth-generation (5G) of cellular communication networks is desired to operate at the mm-wave frequency band, which has different propagation constraints like relatively high path losses and atmospheric absorption. To mitigate these effects, it is crucial to construct a low-cost and low-profile antenna array which maintains high performance over a broad frequency spectrum. In this respect, microstrip patch antenna (MPA) arrays are considered as a candidate antenna type. But, the gain of MPA is low, the bandwidth is too narrow and the integration of a large of elements in the array leads to increased sidelobe level, which decreases radiation efficiency and directivity of the antenna. Besides, the substrate thickness deteriorates the antenna's bandwidth and radiation efficiency by increasing the surface wave and spurious feed radiation. Various design techniques of MPA were reported to alleviate these limitations and improve its performance for 5G communication systems. These include using the slotted patch, defected ground plane, increasing the array elements, changing substrate material, and feeding techniques. But, obtained performance is low for 5G communications. The existing studies' main emphasis was on single element and linear rectangular MPA arrays. A few studies have been carried out to explore the extensive design of planar MPA arrays to improve the bandwidth, gain, and scanning capability of a one-dimensional rectangular MPA array. Thus, to address these challenges, in this study, the performance analysis of a single element, planar 2x2, 4x4, and 8x8 rectangular MPA arrays are presented by introducing a semi-elliptical slot structure on a radiating patch and ground plane, and tuning key dimensions of the antenna. All the proposed MPA arrays are simulated using CST-MW studio and found that the return loss, bandwidth, and gain of the a semi-elliptical slotted single element MPA are -37.784dB, 1.132GHz, 7.128dBi, respectively. The gain, bandwidth, and total efficiency of the studied 2x2, 4x4, and 8x8 MPA array are about 13.24dBi, 16.54dBi, 21.45dBi; 1.33GHz, 1.461GHz, 1.561GHz; 97.03%, 81.72%, 69%, respectively. Likewise, their return loss and VSWR are -43.321dB, -40.665dB, -22.678dB; 1.014, 1.019, 1.159, respectively. The simulation results show that the introduced semi-elliptical slot on the patch and ground plane significantly influences the structure's current distribution. As a result, the radiation efficiency is increased and thereby the bandwidth of the antenna. Moreover, tuning the antenna's key dimensions and etched portion affects the bandwidth, gain, directivity, radiation efficiency, and amount of the antenna's power loss. In general, all the proposed planar rectangular MPA arrays satisfy the requirements of a 5G antenna. As compared to other similar workstherefore, the studied antenna provides a highly competitive and improved performance.