scholarly journals Design and Analysis of Wideband Flexible Self-Isolating MIMO Antennas for Sub-6 GHz 5G and WLAN Smartphone Terminals

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 3031
Author(s):  
Jayshri Kulkarni ◽  
Abdullah G. Alharbi ◽  
Arpan Desai ◽  
Chow-Yen-Desmond Sim ◽  
Ajay Poddar

A single radiator that is a part of four-port diversity Multiple-Input Multiple-Output (MIMO) antenna design is composed of four octagonal rings embedded between the two opposite sides of a T-shaped conductive layer surrounded by inverted angular edge cut L-shaped and E-shaped structures. The radiators are placed at the four corners with common ground at the center of a smartphone to form a four-element mobile MIMO antenna. The printing of the antenna is carried out on the flexible polyamide substrate (dielectric constant = 3.5 and loss tangent = 0.0027) with dimensions of 70 × 145 × 0.2 mm3. A wide impedance bandwidth of (84.12%) 2.39 to 5.86 GHz is achieved for all four radiators. The compact size of the radiators along with their placement enables the proposed MIMO antenna to occupy much less area while preserving the space for 2G/3G/4G antennas. The placement of the antennas results in self-isolation between antenna elements by achieving isolation greater than 17.5 dB in the desired operating bands. Furthermore, besides showing a high efficiency of 85% and adequate gain above 4 dBi, good diversity performances such as Envelope Correlation Coefficient (ECC) of less than 0.05, Diversity Gain (DG) of above 9.8 dB, Mean Effective Gain (MEG) of −3.1 dB, Channel Capacity of 21.50 bps/Hz, and Total Active Reflection Coefficient (TARC) of below −10 dB are achieved by the flexible MIMO smartphone antenna. The effect of bending along the X and Y-axis on the performance of the proposed MIMO antenna is also analyzed where decent performance is observed. This makes the proposed flexible four-element MIMO antenna a potential candidate to be deployed in future smartphones.

2016 ◽  
Vol 9 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Garima Srivastava ◽  
B. K. Kanuijia ◽  
Rajeev Paulus

A compact printed 2 × 2 ultrawideband (UWB) multiple input multiple output (MIMO) antenna with a single circular patch as a common radiator for both the antenna elements is presented in this paper. A single circular patch is excited by two tapered CPW feeds for dual polarization. To improve the isolation between two ports, a rectangular slot of dimension L1 × W1 is created in the radiator. The UWB MIMO antenna has impedance bandwidth of 3–12 GHz with a isolation better than 17 dB between the two ports. The envelope correlation coefficient and the capacity loss are evaluated to ensure the good diversity performance of UWB MIMO antenna. The antenna has a compact size of 45 × 45 mm2 and is fabricated on low cost FR4 substrate and measured using Agilent VNA. The simulated and measured results show that the proposed UWB antenna is good candidate for UWB MIMO applications.


2019 ◽  
Vol 16 (10) ◽  
pp. 4242-4248
Author(s):  
Manoj Kapil ◽  
Manish Sharma

In this research article, a compact MIMO (Multiple-Input-Multiple-Output) antenna with inclusion of two notched bands characteristics is presented. Designed MIMO antenna consist of dual radiating patches printed on one surface of the substrate which covers measured wide impedance bandwidth of 2.88 GHz–19.98 GHz and satisfies bandwidth ratio more than 10:1 for superwideband with compact size of 18 mm × 34 mm. Two radiating patch are placed symmetrically for MIMO configuration and notched bands to eliminate WiMAX/C and WLAN bands are obtained by attaching inverted T-shaped stub on radiating patch and etched inverted U-shape slit in microstrip feed. Isolation between the two radiating patch is maintained by adding two L-shaped stub in slotted rectangular ground plane. Measured radiation pattern are stable in operating band and offers maximum 4.23 dBi and 89% gain and radiation efficiency respectively. Moreover, antenna shows good diversity performance with Envelope-Correlation-Coefficient (ECC) < 0.5, Directive-Gain (DG) > 9.95 dB and Total-Active-Reflection Coefficient (TARC) < -30 dB.


Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 994 ◽  
Author(s):  
Li ◽  
Wei ◽  
Tan ◽  
Lei ◽  
Wu ◽  
...  

A planar flexibly extensible multiple-input–multiple-output (MIMO) antenna array with a self-isolation property is proposed. The main characteristics of the proposed array are: (i) no extra isolation structure is required to improve isolation between elements; (ii) elements are arranged with each other with a spacing of 0 mm, (iii) the configuration can be flexibly extended to a large antenna array according to actual requirements. For a test example, the practical processing and testing of an eight-element array is conducted. The tested results demonstrate that the proposed design possesses wide impedance bandwidth (IBW) of 65% and very good isolation (>18 dB) across the operating bandwidth, which match well with the simulated ones. Moreover, envelope correlation coefficient (ECC) is calculated to valuate MIMO performance; an acceptable ECC (lower than 0.05) suggests that the proposed configuration has good diversity performance and can be a potential candidate for MIMO communications.


2020 ◽  
Vol 35 (8) ◽  
pp. 887-892
Author(s):  
Li-Yan Chen ◽  
Wei-Si Zhou ◽  
Jing-Song Hong ◽  
Muhammad Amin

A compact eight-port coplanar waveguide (CPW)-fed ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna with band-notched characteristics in a small size of 54×54×0.8 mm3 is proposed in this paper. The eight-port MIMO antenna consists of four two-port MIMO antennas. For each two-port MIMO antenna, two monopole antenna elements are printed on the FR4 substrate and placed perpendicularly to each other. To increase impedance bandwidth and improve the isolation, a stub is positioned in the middle of two radiating elements. The band-notched characteristic are achieved by etching two L-shaped resonator slots on each radiating elements, respectively. The S11 reflection coefficients, coupling isolation, radiation patterns, peak gain and radiation efficiencies of the MIMO antenna are measured. The MIMO performance of the proposed antenna is analyzed and evaluated by the envelope correlation coefficient (ECC) and total active reflection coefficient (TARC).


2015 ◽  
Vol 6 (3) ◽  
pp. 1-15 ◽  
Author(s):  
Wan Noor Najwa Wan Marzudi ◽  
Zuhairiah Zainal Abidin ◽  
Siti Zarina Mohd Muji ◽  
Yue Ma ◽  
Raed A. Abd-Alhameed

This paper presented a planar printed multiple-input-multiple-output (MIMO) antenna with a dimension of 100 x 45 mm2. It composed of two crescent shaped radiators placed symmetrically with respect to the ground plane. Neutralization line applied to suppress mutual coupling. The proposed antenna examined both theoretically and experimentally, which achieves an impedance bandwidth of 18.67% (over 2.04-2.46 GHz) with a reflection coefficient < -10 dB and mutual coupling minimization of < -20 dB. An evaluation of MIMO antennas is presented, with analysis of correlation coefficient, total active reflection coefficient (TARC), capacity loss and channel capacity. These characteristics indicate that the proposed antenna suitable for some wireless applications.


Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1083
Author(s):  
Saifur Rahman ◽  
Xin-cheng Ren ◽  
Ahsan Altaf ◽  
Muhammad Irfan ◽  
Mujeeb Abdullah ◽  
...  

In this work, a new Multiple Input Multiple Output (MIMO) antenna system with a novel shape inspired by nature is proposed for Fifth-Generation (5G) communication systems. The antenna is designed on a Rogers 5880. The dielectric constant of the substrate is 2.2, and the loss tangent is assumed to be 0.0009. The gain of the system for the desired bandwidth is nearly 8 dB. The simulated and the measured efficiency of the proposed system is 95% and 80%, respectively. To demonstrate the capability of the system as a potential candidate for future 5G communication devices, MIMO key performance parameters such as the Envelope Correlation Coefficient (ECC) and Diversity Gain (DG) are computed. It is found that the proposed system has low ECC, constant DG, and high efficiency for the desired bandwidth.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Abubaker Ahmed Elobied ◽  
Xue-Xia Yang ◽  
Ningjie Xie ◽  
Steven Gao

This paper presents a close-spaced dual-band 2 × 2 multiple-input multiple-output (MIMO) antenna with high isolation based on half-mode substrate integrated waveguide (HMSIW). The dual-band operation of the antenna element is achieved by loading a rectangular patch outside the radiating aperture of an HMSIW cavity. The HMSIW cavity is excited by a coaxial probe, whereas the rectangular patch is energized through proximity coupling by the radiating aperture of HMSIW. The antenna elements can be closely placed using the rotation and orthogonal arrangement for a 2 × 2 array. Small neutralization lines at the center of the MIMO antenna can increase the isolation among its elements by around 10 dB in the lower band and 5 dB in the higher band. A prototype of the MIMO antenna is fabricated and its performance is measured. The measured results show that the resonant frequencies are centered at 4.43 and 5.39 GHz with bandwidths of 110 and 80 MHz and peak gains of 6 and 6.4 dBi, respectively. The minimum isolation in both bands is greater than 35 dB. The envelope correlation coefficient is lower than 0.005 within two operating bands.


2018 ◽  
Vol 11 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Sanjay Chouhan ◽  
Debendra Kumar Panda ◽  
Vivek Singh Kushwah ◽  
Pankaj Kumar Mishra

AbstractA four-element wide-band octagonal ring-shaped antenna is proposed for human interface device and S-band applications. The isolation structure comprises a parasitic element and a T-shaped structure. The antenna has −10 dB impedance bandwidth 63% (2.1–4.0 GHz) with miniaturized dimension of 54.98 mm × 76 mm. The multiple input multiple output (MIMO) antenna gain is 2.83 dBi at the 2.4 GHz resonant frequency. The designed MIMO has envelop correlation coefficient of 0.026 in the 2:1 VSWR band. The −10 dB total active reflection coefficient bandwidth of 1.2 GHz has been achieved in the entire frequency band, and has MEG value of ≤−3 dB. The specific absorption rate has found below the safety limit near the human head, palm and wrist.


Frequenz ◽  
2017 ◽  
Vol 71 (5-6) ◽  
Author(s):  
Lingsheng Yang ◽  
Ming Ji ◽  
Biyu Cheng ◽  
Bo Ni

AbstractIn this letter, an eight-element Multiple-input multiple-output (MIMO) antenna system for LTE mobile handset applications is proposed. The antenna array consists of eight 3D inverted F-shaped antennas (3D-IFA), and the measured –10 dB impedance bandwidth is 3.2–3.9 GHz which can cover the LTE bands 42 and 43 (3.4–3.8 GHz). By controlling the rotation of the antenna elements, no less than 10 dB isolation between antenna elements can be obtained. After using the specially designed meandered slots on the ground as decoupling structures, the measured isolation can be further improved to higher than 13 dB between the antenna elements at the whole operating band.


2017 ◽  
Vol 9 (8) ◽  
pp. 1763-1780 ◽  
Author(s):  
Leeladhar Malviya ◽  
Rajib Kumar Panigrahi ◽  
M. V. Kartikeyan

Multiple input multiple output (MIMO) antenna is at core of the presently available wireless technologies. The design of MIMO antennas over a limited space requires various approaches of mutual coupling reduction, otherwise gain, efficiency, diversity gain, and radiation patterns will be severely affected. Various techniques have been reported in literature to control this degrading factor and to improve the performance of the MIMO antennas. In this review paper, we have carried out an extensive thorough investigation of diversity and mutual coupling (correlation) reduction techniques in compact MIMO antennas.


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