Future Smartphone: MIMO Antenna System for 5G Mobile Terminals

In this article, an inverted L-shaped monopole eight elements Multiple Input Multiple Output (MIMO) antenna system is presented. The multi-antenna system is designed on a low cost 0.8 mm thick FR4 substrate having dimensions of 136 x 68 mm(2) resonating at 3.5GHz with a 6dB measured bandwidth of 450MHz, and with inter element isolation greater than 15 dB and gain of 4 dBi. The proposed design consists of eight inverted L-shaped elements and parasitic L-shaped strips extending from the ground plane. These shorted stripes acted as tuning stubs for the four inverted L-shaped monopole elements on the side of chassis. This is done to achieve the desired frequency range by increasing the electrical length of the antennas. A prototype is fabricated, and the experimental results show good impedance matching with reasonable measured isolation within the desired frequency range. The MIMO performances, such as envelope correlation coefficient (ECC) and mean effective gain (MEG) are also calculated along with the channel capacity of 38.1bps/Hz approximately 2.6 times that of 4 x 4 MIMO system. Due to its simple shape and slim design, it may be a potential chassis for future handsets. Therefore, user hand scenarios, i.e. both single and dual hand are studied. Also, the effects of hand scenarios on various MIMO parameters are discussed along with the SAR. The performance of the proposed system in different scenarios suggests that the proposed structure holds promising future within the next generation radio smart phones

Sub-6GHz 4G/5G Conformal Glasses Antennas

© 2013 IEEE. The difficulty of antenna design applied to glasses is that the structure of glasses is too single, and the space available for antenna design is greatly limited. In this background, the integrated design of 4G antennas and 5G antennas applied to glasses is proposed in this paper. The most important highlight of this design is that it makes full use of the limited three-dimensional space structure provided by glasses and achieves the perfect combination of the antenna and glasses in the physical structure. Specifically, two antennas for 4G communication are arranged on two glasses frames, and four antennas for 5G communication are arranged on two glasses legs. In this way, we can make full use of the space provided by the glasses to design antennas and ensure that there is a certain distance between the 4G antennas and 5G antennas so that the performance of both 4G antennas and 5G antennas can be guaranteed. The 4G antenna consists of a loop structure printed on the frame and leg of the glasses and a parasitic branch strip printed on the front of the leg of the glasses. The resonance modes of the 4G antenna are mainly loop, monopole, and dipole modes, which can cover two 4G bands of 0.824-0.96 GHz and 1.71-2.69 GHz. Each 5G antenna mainly comes from the open slot mode etched on the metal ground surface of an FR4 substrate of the glasses leg. In addition, the slot antennas operate in two 5G bands of 3.3-3.6 GHz and 4.8-5.0 GHz. Finally, the glasses and the antennas are fabricated based on FR4 substrates and measured. The measured results show that the proposed antennas perform well and have the potential to be used in 4G/5G communications through glasses

Uni-Planar MIMO Antenna for Sub-6 GHz 5G Mobile Phone Applications

This article presents the design of a uni-planar MIMO antenna system for sub-6 GHz 5G-enabled smartphones. The MIMO antenna designed comprises four loop-shaped radiators placed at each corner of the mobile phone board, which follows the principle of pattern diversity. The single-antenna element resonates at 3.5 GHz, its impedance bandwidth is noted to be 1.28 GHz (3-4.28 GHz) for S11 90%. The isolation of >10 dB between antenna elements is achieved for the MIMO configuration. Furthermore, the MIMO antenna designed provides enough radiation coverage to support different sides of the mobile phone board, which is an important feature for future 5G-enabled handsets. In addition, the impacts of human hands and heads on MIMO antenna performance are investigated, and acceptable performance in the data and conversation modes is observed.The authors sincerely appreciate the support from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant 80153

Performance analysis of smart optimization antenna for wireless networks

Antenna design has significantly advanced as a result of the widespread need for wireless communications and data substitution through wireless devices. The research article's goal is to provide a conceptual framework, difficulties, and opportunities for a source as well as a general overview of the antenna used in wireless communications applications. In this proposed research, we will go over a variety of topics related to mobile communication and fifth generation (5G) technologies, including its pros and benefits. A thorough comparison between the expected properties of the antennas and each generation, from 1st generation (1G) to 5G, is also included. This article also provides an overview of the investigated 5G technologies and various antenna designs

Wideband Back-Cover Antenna Design Using Dual Characteristic Modes With High Isolation for 5G MIMO Smartphone

© 2022 IEEE - All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1109/TAP.2022.3145456A novel method of designing a wideband high isolated dual-antenna pair using dual characteristic modes (CMs)is presented for fifth-generation (5G) multiple-input multiple output (MIMO) smartphone applications. A set of orthogonal CMs resonating from the square-loop slot is first introduced and works for the lower band. Then, another set of orthogonal CMs resonating from the edge branches is introduced with a shared compact radiator and works for the higher band. In combination with two sets of degenerated CMs and a capacitive coupling feeding structure, the proposed dual-antenna pair achieves abroad impedance bandwidth and high isolation without the need for any external decoupling structures. Based on this dual-antenna pair, an 8×8 MIMO array is developed and integrated into the back cover of a smartphone, which realizes zero ground clearance on the system circuit board. To verify the design concept, prototypes of the antenna pair and MIMO array were fabricated and measured. It shows that experimental results agree well with the simulation results. More importantly, the presented 8×8 MIMO array has high isolation of more than 20 dBis achieved across the operating band of 3.3-3.8 GHz.Peer reviewedFinal Accepted Versio

Dual-Band Eight-Element MIMO Array Using Multi-Slot Decoupling Technique for 5G Terminals

This paper presents a dual-band eight-element multiple-input multiple-output (MIMO) array using a multi-slot decoupling technique for the fifth generation (5G) mobile communication. By employing a compact dual-loop antenna element, the proposed array obtains two broad bandwidths of 12.2% and 15.4% for sub-6GHz operation. To reduce the mutual coupling between antenna elements, a novel dual-band decoupling method is proposed by employing a multi-slot structure. The proposed MIMO array achieves 15.5-dB and 19.0-dB isolations across the two operating bands. Furthermore, three decoupling modes generated by different bent slots can be independently tuned. Zero ground clearance is also realized by the coplanar arrangement of the antenna elements and decoupling structures. The proposed MIMO array was simulated, fabricated, and measured. Experimental results agree well with the simulations, showing that the dual-band MIMO array has good impedance matching, high isolation, and high efficiency. In addition, the envelope correlation coefficient and channel capacity are calculated and analyzed to validate the MIMO performance of the 5G terminal array. Such a dual-band high-isolation eight-element MIMO array with zero ground clearance is a promising candidate for 5G or future mobile applications

Wideband and High Gain Array Antenna for 5G Smart Phone Applications Using Frequency Selective Surface

This work presents an eight element array antenna with single layer frequency selective surface (FSS) to obtain high gain. The eight elements are fed by single port. The FSS consists of 14 × 6 unit cells with one unit cell size is 5 × 5 mm2 having wideband behavior. The antenna uses Rogers RT Duroid 5880 substrate and giving very wide bandwidth from 20 GHz to 65 GHz, covering millimeter wave 5G bands (including 28 GHz, 38 GHz and 60 GHz). The designed FSS is showing stop band transmission characteristics below −10 dB threshold from 25 GHz to 42 GHz and 59 GHz to 61 GHz. The eight element antenna integrated with the FSS reflector, which results an improvement in the gain level from 12 dB to 15 dB at 28 GHz, from 10 dB to 12 dB at 38 GHz, and from 9.5 to 11 dB at 60 GHz. The dimensions of the antenna are 65 × 27 × 0.857 mm3. The proposed antenna shows stable gain and directional radiation patterns. The simulation findings are experimentally confirmed, by testing the fabricated prototypes of the proposed antenna system

High Isolated 10-MIMO Antenna Elements for 5G Mobile Applications

The enormous increase in gadgets has resulted in a data rate shortage insufficient to satisfy the user's needs. The multiple input multiple output (MIMO) technique is substantially deployed in the 5G wireless communication system to increase channel capacity and provide sufficient throughput. However, MIMO antennas are associated with mutual coupling, especially between closely spaced antenna elements, resulting in a low MIMO performance. Therefore, effective isolation techniques are essential to reduce the mutual coupling between the adjacent MIMO antenna elements. A hybrid decoupling technique of self-isolation and an orthogonal mode approach has been proposed to provide significant isolation for high MIMO order 5G mobile applications. A compact self-isolated 10 × 10 MIMO antenna system has been proposed for 5G mobile phone applications operating at the 3.5 GHz frequency band. The antennas act as radiating and isolating elements simultaneously, providing significant isolation. Furthermore, the self-isolated 10-MIMO antenna elements are printed on double side edges of FR-4 small substrates orthogonal to the system substrates, forming an orthogonal mode that enhances the self-decoupling approach. The s-parameters results indicate significant isolation of less than -19 dB between the adjacent 10-MIMO antenna elements. Likewise, the evaluation results of the MIMO performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and channel capacity Loss (CCL), are less than 0.006, 9.97 dB, -10 dB, and 0.08 bits/s/Hz respectively. The isolation result and the evaluated MIMO performance metrics demonstrate that the proposed 10-MIMO antenna system is sufficient for 5G mobile applications.   &nbsp