scholarly journals 8-Port Semi-Circular Arc MIMO Antenna with an Inverted L-Strip Loaded Connected Ground for UWB Applications

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.

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.


Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sachin Kumar Yadav ◽  
Amanpreet Kaur ◽  
Rajesh Khanna

Abstract In this article, cross-shaped metallic parasitic strips based two radiator element multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) is excited by quadrature wave transformer microstrip feedline, designed, simulated and fabricated for ultra-wideband (UWB) applications. The proposed MIMO antenna structure is implemented with the help of two rectangular-shaped radiator elements that supports three modes HE11δ , HE21δ , and HE12δ at 4.4, 8.3, 10.8 GHz respectively. These fundamental and higher-order modes are supported to wide impedance bandwidth. Inverted T-shaped metallic strip and ground stub to improve the impedance bandwidth 104.6% (3.3–10.8 GHz) with 5.7 dBi peak gain, to enhance the coupling coefficient by stub, scissor-shaped defected ground structure and cross-shaped metallic parasitic strips are used in the existed structure. The MIMO diversity parameters are implemented as simulated ECC ≤ 0.003, DG ≥ 9.98 dB, and CCL ≤ 0.68. All the obtained MIMO antenna parameters are within the acceptable limit for providing high data rate for UWB applications.


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.


2018 ◽  
Vol 10 (8) ◽  
pp. 948-955 ◽  
Author(s):  
Ling Wu ◽  
Yingqing Xia ◽  
Xia Cao ◽  
Zhengtao Xu

AbstractA simple multiple-input-multiple-output (MIMO) antenna with quad-band-notched characteristics for ultra-wideband (UWB) system is proposed and tested in the article. Based on two similar radiators, the UWB-MIMO system only occupies 22 mm × 28 mm. By etching an inverted L-like meander slot, two inverted L-shaped slots, and adding a C-shaped stub beside the feeding line, four notched bands are realized (3.25–3.6, 5.05–5.48, 5.6–6, and 7.8–8.4 GHz) to suppress interference from WiMAX, lower WLAN, upper WLAN, and uplink of X-band satellite communication system. With a T-like stub extruding from the ground plane, port isolation is effectively improved. The results show that the antenna covers 3.1–10.6 GHz UWB frequency band except four rejected bands and has high isolation of better than −20 dB over most of the frequency band. Moreover, envelope correlation coefficient and good radiation patterns also prove that the introduced antenna is suitable for UWB applications.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Minghuan Wang ◽  
Jingchang Nan ◽  
Jing Liu

A miniaturized ultra-wideband multiple-input multiple-output (UWB MIMO) two-port antenna with high isolation based on FR4 is designed in this article. The size of the antenna is only 18 × 28 × 1.6 mm3. The MIMO antenna consists of two identical antenna elements symmetrically placed on the same dielectric substrate in opposite directions. By loading three crossed X-shaped stubs between two unconnected ground planes, high isolation and good impedance matching are achieved. The working frequency band measured by this UWB MIMO antenna is 1.9–14 GHz, and the isolation is kept above 20.2 dB in the whole analysis frequency band. Good radiation characteristics as well as envelope correlation coefficient (ECC, <0.09), mean effective gain (MEG), and channel capacity loss (CCL) in the passband meet the requirements of the application, which can be applied to the UWB wireless communication system. To verify the applicability of the proposed method for enhancing the isolation between antenna elements, the two-port antenna structure was extended to a four-port antenna structure. In the case of loading the X-shaped stubs to connect to the ground plane, the isolation of the antenna is maintained above 15.5 dB within 1.7–14 GHz.


2021 ◽  
pp. 1-7
Author(s):  
Ahmed Shaker ◽  
◽  
Ayman Haggag

A compact ultra-wideband (UWB) Multiple-Input-Multiple-Output (MIMO) antenna with a notched band is presented. The proposed design consists of four unipolar UWB radiators, and these monopole radiators are placed perpendicular to each other to exploit polarization diversity, where the four-element ultra-wideband (UWB) Multiple-Input-Multiple-Output (MIMO) antenna is presented. The total size of the antenna is 60x60 mm2. The operating frequency of the antenna is 3.1–11 GHz with a return loss of less than 10 dB, except at the notched band of 4.9– 5.9 GHz. This antenna consists of an isosceles trapezoidal plate with a circular notch cut and two transitional steps as well as a partial ground plane. For UWB bandwidth enhancement techniques: use of a partial ground plane, and modify the gap between the radioactive element and ground plane technique, using steps to control the resistance stability and a notch cut technique. The notch cut from the radiator is too used to reduce the size of the plane antenna. The measured -10 dB return loss bandwidth for the designed antenna is about 116.3% (8.7 GHz). The MIMO antenna does not require any additional structure to improve insulation. The proposed antenna supplies an acceptable radiation pattern and relatively flat gain over the entire frequency band.


Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1174 ◽  
Author(s):  
Pawan Kumar ◽  
Shabana Urooj ◽  
Areej Malibari

This article presents a compact, planar, quad-port ultra-wideband (UWB) multiple-input–multiple-output (MIMO) antenna with wide axial ratio bandwidth (ARBW). The proposed MIMO design consists of four identical square-shaped antenna elements, where each element is made up of a circular slotted ground plane and feed by a 50 Ω microstrip line. The circular polarization is achieved using a protruding hexagonal stub from the ground plane. The four elements of the MIMO antenna are placed orthogonally to each other to obtain high inter-element isolation. FR-4 dielectric substrate of size 45 × 45 × 1.6 mm3 is used for the antenna prototype, and a good agreement is noticed among the simulated and experimental results. The proposed MIMO antenna shows 3-dB ARBW of 52% (3.8–6.5 GHz) and impedance bandwidth (S11 ≤ −10 dB) of 144% (2.2–13.5 GHz).


2019 ◽  
Vol 12 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Sachin Kumar ◽  
Gwan Hui Lee ◽  
Dong Hwi Kim ◽  
Wahab Mohyuddin ◽  
Hyun Chul Choi ◽  
...  

AbstractA new design method of an ultra-wideband circularly-polarized planar multiple-input-multiple-output (MIMO) antenna is presented in this paper. The proposed MIMO antenna consists of four unit cell antennas, being comprised of a microstrip feed line and a square slotted ground plane. In the proposed unit cell design, a circular stub is protruded from the ground plane strip for achieving circular polarization. The unit cell of the MIMO antenna is optimized by adjusting design parameters. The compact four-port MIMO antenna prototype is designed on the FR4 substrate with the overall dimensions of 45 × 45 × 1.6 mm3. The proposed four-port MIMO antenna design provides an impedance bandwidth (S11 < −10 dB) of 112% (3.1–11 GHz) and a 3 dB axial ratio bandwidth of 36% (4.8–6.9 GHz). The performance of the fabricated MIMO antenna shows good agreement between the EM simulation and measurement results.


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.


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