scholarly journals Minimization of Mutual Coupling Using Neutralization Line Technique for 2.4 GHz Wireless Applications

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.

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
A. Mchbal ◽  
N. Amar Touhami ◽  
H. Elftouh ◽  
A. Dkiouak

A compact ultra-wideband (UWB) multiple input-multiple output (MIMO) antenna with high isolation is designed for UWB applications. The proposed MIMO antenna consists of two identical monopole antenna elements. To enhance the impedance matching, three slots are formed on the ground plane. The arc structure as well as the semicircle with an open-end slot is employed on the radiating elements the fact which helps to extend the impedance bandwidth of the monopole antenna from 3.1 up to 10.6 GHz, which corresponds to the UWB band. A ground branch decoupling structure is introduced between the two elements to reduce the mutual coupling. Simulation and measurement results show a bandwidth range from 3.1 to 11.12 GHz with |S11_|<−15 dB, |S21_|<−20 dB, and ECC < 0.002.


Author(s):  
Harleen Kaur ◽  
Hari Shankar Singh ◽  
Rahul Upadhyay

Abstract In this research study, a compact dual-polarized co-radiator ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with improved impedance bandwidth and isolation is proposed for wireless applications. The designed co-radiator has an overall area of 0.3λo × 0.3λo mm2 (where, λo is free space wavelength corresponding to the lower cut-off frequency, i.e., 3.1 GHz). The proposed resonator comprises of a hybrid geometry which is created with the combinations of a circular-shaped patch, a square, and two rectangular stubs. It is centrally aligned between two 50 Ω micro-strip feed lines that are positioned orthogonal to each other. Further, the modified ground plane is attached with the end-loaded line which provides broadband isolation over entire UWB frequency band. The simulated results of the proposed antenna exhibit wideband characteristics with impedance bandwidth of 3.1–16.9 GHz with minimum isolation of −15 dB. Moreover, all the radiation performance parameters are analyzed and discussed. Some important diversity parameters such as envelope correlation coefficient, mean effective gain, effective diversity gain, and channel capacity loss have also been evaluated. Furthermore, all the measured results of proposed antenna agree well with the simulated results which make the proposed antenna a suitable candidate for UWB-MIMO wireless applications.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jiwan Ghimire ◽  
Kwang-Wook Choi ◽  
Dong-You Choi

The correlation between the antennas of multiple-input, multiple-output (MIMO) systems in limited spaces and size degrades the performance and capacity by either using complex coupling or decoupling structures. For isolation improvement, this paper presents the simple design of a compact high-isolation ultra-wideband (UWB) MIMO antenna with a circular parasitic element at the back side of the radiating patch, thereby creating the reverse coupling and helping reduce the mutual coupling at the upper part of the frequency bands, and a small rectangular notch at the ground plane to extend the impedance bandwidth of the monopole antenna. This approach eliminates the use of complex coupling or decoupling structures and complex feeding networks. A novel feature of our design is that the MIMO antenna exhibits a very low envelope correlation coefficient (ECC < 0.007) with high diversity gain (DG > 9.99) and wide impedance bandwidth of 139 % from 3.1 to 17.5 GHz applicable for not only UWB application, but also next generation wireless communication, 5G. The high peak gain over the entire UWB and the upper part of the overall frequency band ensure that the antenna can be used in MIMO applications owing to the close agreement between the simulated and measured results.


2017 ◽  
Vol 10 (3) ◽  
pp. 360-367 ◽  
Author(s):  
Sonika Priyadarsini Biswal ◽  
Sushrut Das

A compact printed quadrant shaped monopole antenna is introduced in this paper as a good prospect for ultra wideband- multiple-input multiple-output (UWB-MIMO) system. The proposed MIMO antenna comprises two perpendicularly oriented monopoles to employ polarization diversity. An open circuit folded stub is extended from the ground plane of each radiating element to enhance the impedance bandwidth satisfying the UWB criteria. Two ‘L’ shaped slots are further etched on the radiator to provide good isolation performance between two radiators. The desirable radiator performances and diversity performances are ensured by simulation and/or measurement of the reflection coefficient, radiation pattern, realized peak gain, envelope correlation coefficient (ECC), diversity gain, mean effective gain (MEG) ratio and channel capacity loss (CCL). Results indicate that the proposed antenna exhibits 2.9–11 GHz 10 dB return loss bandwidth, mutual coupling <−20 dB, ECC < 0.003, MEG ratio ≈ 1, and CCL < 0.038 Bpsec/Hz, making it a good candidate for UWB and MIMO diversity application.


2019 ◽  
Vol 8 (1) ◽  
pp. 75-81
Author(s):  
N. Al Shalaby ◽  
S. G. El-Sherbiny

In this paper, A multiple input Multiple Output (MIMO) antenna using two Square Dielectric Resonators (SDRs) is introduced. The mutual coupling between the two SDRAs is reduced using two different methods; the first method is based on splitting a spiral slot in the ground plane, then filling the slot with dielectric material, "E.=2.2". The second method is based on inserting a copper parasitic element, having the same shape of the splitted Spiral, between the two SDRAs.  The effect of replacing the copper parasitic element with Carbon nanotubes (CNTs) parasitic element "SOC12 doped long-MWCNT BP" is also studied. The antenna system is designed to operate at 6 GHz. The analysis and simulations are carried out using finite element method (FEM). The defected ground plane method gives a maximum isolation of l8dB at element spacing of 30mm (0.6λo), whereas the parasitic element method gives a maximum isolation of 42.5dB at the same element spacing.


2014 ◽  
Vol 8 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Mohammed Younus Talha ◽  
Kamili Jagadeesh Babu ◽  
Rabah W. Aldhaheri

A novel compact multiple-input–multiple-output (MIMO) antenna system operating from 5 to 7.3 GHz is proposed for wireless applications. It comprises of two similar antennas with microstrip feeding and radiating patches developed on a reduced ground plane. The developed antenna system resonates at a dual-band of 5.4 and 6.8 GHz frequencies, giving an impedance bandwidth of 38% (based on S11 < −10 dB). The unique structure of the proposed MIMO system gives a reduced mutual coupling of −27 dB at 5.4 GHz resonant frequency and −19 dB at 6.8 GHz resonant frequency and in the entire operating band the coupling is maintained well below −16 dB. The envelope correlation coefficient of the proposed MIMO system is calculated and is found to be less than 0.05 in the operating band. The measured and simulation results are found in good agreement.


2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Chia-Hao Wu ◽  
Jwo-Shiun Sun ◽  
Bo-Shiun Lu

This paper presents a compact four-element multiple-input–multiple-output (MIMO) antenna design operating within the WiFi 802.11 ac bands (5.2–5.84 GHz) for a smartwatch. The antenna is fabricated using a polyamide substrate and embedded into the strap of a smartwatch model; the strap is created using three-dimensional etching of plastic materials. The four-element MIMO antenna is formed by four monopole antennas, has a simple structure, and is connected to the system ground plane of the smartwatch. Due to the stub and notched block between two antennas and the slit in the system ground, the four-element MIMO antenna exhibits favorable isolation. Moreover, the envelope correlation coefficient of the antennas is considerably lower than 0.005 in the operating band. The measured −6 dB impedance bandwidths of the four elements of the antenna (Ant1–Ant4) with the human wrist encompass the WiFi 802.11 ac range of 5.2–5.84 GHz; moreover, an isolation of more than 20 dB is achieved. The measured antenna efficiency with and without a phantom hand are 45%–55% and 93%–97%, respectively.


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.


Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1476
Author(s):  
Tathababu Addepalli ◽  
Arpan Desai ◽  
Issa Elfergani ◽  
N. Anveshkumar ◽  
Jayshri Kulkarni ◽  
...  

Multiple-input multiple-output (MIMO) antennas with four and eight elements having connected grounds are designed for ultra-wideband applications. Careful optimization of the lines connecting the grounds leads to reduced mutual coupling amongst the radiating patches. The proposed antenna has a modified substrate geometry and comprises a circular arc-shaped conductive element on the top with the modified ground plane geometry. Polarization diversity and isolation are achieved by replicating the elements orthogonally forming a plus shape antenna structure. The modified ground plane consists of an inverted L strip and semi ellipse slot over the partial ground that helps the antenna in achieving effective wide bandwidth spanning from (117.91%) 2.84–11 GHz. Both 4/8-port antenna achieves a size of 0.61 λ × 0.61 λ mm2 (lowest frequency) where 4-port antenna is printed on FR4 substrate. The 4-port UWB MIMO antenna attains wide impedance bandwidth, Omni-directional pattern, isolation >15 dB, ECC < 0.015, and average gain >4.5 dB making the MIMO antenna suitable for portable UWB applications. Four element antenna structure is further extended to 8-element configuration with the connected ground where the decent value of IBW, isolation, and ECC is achieved.


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