Design and Implementation of Multi Input Multi Output (MIMO) Antenna in 5G Mobile Communication Systems /

Abstract

The mobile access technology is going through a revolutionary change every ten years. Each generation of mobile technology has provided significant performance enhancements. These rapid changes are in response to the capacity demands resulting from the massive data growth over the last ten years. 5G aims to a revolutionary leap forward in terms of data rates, efficiency, capacity and massive connectivity. The requirements of 5G are expected to be met by utilizing the bandwidths in both the sub 6-GHz and mm-wave using very large antenna array and MIMO technology. The MIMO antenna technology is widely known for its ability to enhance the system capacity, as well as mitigate the negative effect of the multipath interference. Even though the 5G MIMO is capable of boosting the spectrum efficiency and the data throughput, it is not an easy task to integrate multiple antenna elements into a smartphone or even a base station. To meet the requirement of a closely packed antenna arrangement and to optimize the isolation, the decoupling techniques have become an underlying need for future antenna designs. Furthermore, considering the future demand of multi-band and multi-mode massive MIMO applications, besides the 4G main and the diversity antennas, additional operating bands and resonant modes is supported by the 5G antenna elements, which is now a challenging topic for antenna engineer. The main objective of this thesis is to design a novel antenna that operates for both 4G/5G mobile communication systems. The total dimension of the SCB is 150 x 80 mm2 that would fit in the commercial cellular phones. The size of proposed antenna is 11.7 x 15.9 mm2. It is constructed of four monopoles of various shapes and dimensions with two rectangular bricks on the top layer, and a stub and open slot that are etched in the ground plane. Each part of the antenna contributed to different frequency bands. Different bandwidth enhancement V techniques were investigated and their effect on the total bandwidth is recorded. This single element antenna structure covers frequency ranges from 1.4 to 2.64 GHz and from 3.32 to 4.64 GHz, which is equivalent to 23 bands of the total (32) 5G NR bands and 30 bands of the total (76) LTE bands. The antenna has an efficiency of 80% and a gain of 5 dBi. The proposed antenna element satisfies the desired design specifications. Consequently, it is arrayed to form an 8-element MIMO antenna for the smartphones on a SCB of 150 x 80 mm2 and an 8-element MIMO antenna for the base station on a SCB of 140 x 140 mm2. Finally, after designing 8 x 8 MIMO antenna system, the average channel capacity is calculated at the lower boundary and is found to be 17.857 bps/Hz at SNR 10 dB. However, the peak channel capacity is calculated to be 22.9187 bps/Hz at SNR 10 dB. A great enhancement has been done when it is compared with the results of the single element, where the enhancement is 573.7121%