scholarly journals Efficient Isolation of an MIMO Antenna Using Defected Ground Structure

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1265
Author(s):  
Haoran Xing ◽  
Xinyan Wang ◽  
Zhenbin Gao ◽  
Xing An ◽  
Hong-xing Zheng ◽  
...  

To implement efficient isolation between units of a multi-input multi-output (MIMO) antenna, a defected ground structure (DGS) has been investigated. An antenna with two elements operating at 5.8 GHz and fed by coaxial is considered. To reduce mutual coupling between the elements, a zigzag groove is inserted into the center of two elements formed as a DGS. To verify this design, a scattering matrix was tested, such as reflection coefficient S11 and transmission coefficient S21 between two element ports. Meanwhile, radiation pattern, current distribution, envelope correlation coefficient (ECC), and diversity gain of the antenna were simulated and measured. The results showed that the mutual coupling was reduced by 28.8 dB when a DGS was used, and the ECC was less than 0.02. Owing to these good performances, each antenna element can operate almost independently, and this MIMO antenna can be efficiently applied to the narrow band Internet of Things system.

In this work, a Multi-band wearable microstrip patch antenna designed integrated with the defected ground structure(DGS)[1], and the substrate being used is Denim which is flexible[4] and can be easily fabricated on common wearable materials. This Radiating patch antenna is designed with the optimized dimensions and suits appropriately for the communication in wearable electronics as well as in smart textile application. The designed antenna operates at resonating frequencies of 4.885 GHz and 5.57 GHz. Further the design is modified to a 2-element MIMO [2] antenna using T-shaped Stub matching technique to reduce mutual coupling and resonate at frequency of 8GHz by designing and simulating in CST Microwave Studio 2019 software and the enhanced results like Directivity, Gain, E-field are obtained.


2019 ◽  
Vol 14 (2) ◽  
pp. 215-226 ◽  
Author(s):  
Erik Fritz‐Andrade ◽  
Angel Perez‐Miguel ◽  
Ricardo Gomez‐Villanueva ◽  
Hildeberto Jardon‐Aguilar

2016 ◽  
Vol 9 (3) ◽  
pp. 581-590
Author(s):  
Chithradevi Rajagopal ◽  
Nafiza Noorullakhan ◽  
Sreeja Balakrishnapillai Suseela ◽  
Radha Sankararajan

A compact quad band slot antenna with high isolation suitable for multiple-input–multiple-output (MIMO) applications is developed. The quad bands are achieved by introducing slots in a modified, size reduced circular patch antenna. The single-antenna element consists of a substrate sandwiched between a modified circular patch with F shape slot, a feeder line and a via running between the radiating patch and the feeder line. The proposed design resonates at the frequencies of 1.8 GHz (1.7–1.88 GHz), 3.6 GHz (3.50–3.76 GHz), 5.4 GHz (5.25–5.38 GHz), and 7.2 GHz (7.15–7.35 GHz) covering the GSM II, WIMAX, wireless local area network (WLAN), and C-band applications, respectively. The independent tuning of frequency bands is achieved by varying the length of the slots. Orthogonally placed two- and four-element MIMO antenna system are fabricated, tested, and the measurement results are presented. The separation between each element is reduced to 0.085λ while introducing slotted and pulsed stubs to improve isolation between elements. A detailed analysis, including mutual coupling, low correlation, diversity gain, and total array reflection coefficient had been reported. The two- and four-element MIMO antennas achieved correlation as low as 0.005, mutual coupling ≤−15 dB, and diversity gain nearly 10 dB.


2019 ◽  
Vol 11 (4) ◽  
pp. 413-419 ◽  
Author(s):  
Ziyu Xu ◽  
Qisheng Zhang ◽  
Linyan Guo

AbstractA printed multiband Multi-Input Multiple-Output (MIMO) antenna is proposed in this paper. This MIMO antenna system comprises two symmetric printed monopole antennas. Each antenna element consists of multiple bend lines, producing four resonant modes and covering the GSM900, PCS, LTE2300, and 5G bands. Simulated and measured results prove that the proposed MIMO antenna can be applied to traditional 2G, 3G, 4G, and present 5G mobile communication. By etching four inverted L-shaped grooves on its ground plate, mutual coupling between the adjacent antenna elements has been suppressed. This makes the |S21| at all four resonant modes is lower than −40 dB. In addition, its low coupling mechanism has been analyzed by surface current distribution. The designed multiband MIMO antenna provides an idea of reference to realize low mutual coupling between antenna elements, which is also realizable in infrared or optical regimes with appropriate designs.


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