Metamaterial-based massive mimo antenna array for 5G and beyond wireless communication system

Abstract

Fifth generation (5G) and beyond wireless era has resulted in substantial breakthroughs in various industries, including telecommunications, healthcare, and Internet of Things (IoT). These advances are made feasible by using high-frequency spectrums, which surpass the limitations of traditional communication systems. However, the growing demand for wireless communication services outstrips the capabilities of existing technologies, prompting the development of new technologies. Massive multi-input multi-output (M-MIMO) technology has received much attention in the research community due to its ability to dramatically improve wireless communication system capacity while needing only minor increases in bandwidth or power for transmission. The main goal of this thesis is to develop a M-MIMO antenna array system backed up with several unique metamaterials (MTMs) to meet the requirements of developing 5G and 6G wireless communication systems. Two high-gain planar and non-planar antenna systems based MTM have been designed, fabricated, and measured for the upcoming millimeter wave (mm-wave) 5G applications, whereas a third M-MIMO system for 6G applications is developed. First, the planar M-MIMO antenna is designed with 64 elements which are fed with 16 port, whereas each subarray has 2 × 2 rectangular-shaped patches. However, the second M-MIMO antenna is a non-planar 16-port system built on 3D-octagonal-shaped block geometry with eight broadband sides to involve 360 degrees of the coverage area. Each antenna is made up of 2 × 2 y-shaped radiating patches. Moreover, both planar and non-planar mm-wave M-MIMO antennas has been equipped by the proposed epsilon-negative (ENG) and double-negative (DNG) MTMs to enhance performance. Furthermore, a third non-planar M-MIMO antenna for 6G applications is designed, which is one of the main focuses of this work. A novel 3D cross-shaped M-MIMO system is introduced and loaded with unique MTM to serve terahertz frequencies. The antenna system consists of 16 ports distributed across four sides of a cross-shaped Polyimide substrate, with each side integrating 2×2 MIMO systems that share a common ground and loaded with a near-zero-index epsilon-negative (NZI-ENG) MTM decoupling structure to enhance the isolation between array elements. The parameters of the three developed antenna systems have been optimized using commercial Computer Simulation Technology software (CST). Utilizing the advantages of the proposed ENG/DNG MTMs to the proposed mm-wave M-MIMO antennas resulted with enhanced performance in terms of isolation, gain and efficiency. The performance of the planar M-MIMO antenna, which operates within 25.5-29 GHz, reached an increased efficiency up to 99%, along with lower measured isolation levels of up to 25 dB and a maximum gain of 20 dBi. Whereas the 3D octagonal-shaped antenna system which operates on the frequency span of 24.8-28.6 GHz obtained a high isolation level of 23 dB, a maximum measured gain of 14.9 dBi, and an efficiency of up to 97%. As for the 6G non-planar cross-shaped M-MIMO antenna which operates between 0.24 to 0.40 THz frequency band, the MTM decoupling structure effectively accomplishes an isolation of greater than 24 dB for, boosting antenna performance to reach a maximal gain of 13.2 dBi and an efficiency of 92%. The proposed non-planar 3D-MIMO antenna system has tremendous potential for use in wireless communication applications of the 6G.