scholarly journals Isolation Enhancement Using a Hybrid Technique in an Eight-Element UWB MIMO Antenna Design

2020 ◽  
Vol 9 (3) ◽  
pp. 56-65
Author(s):  
A. Mchbal ◽  
N. Amar Touhami ◽  
H. Elftouh ◽  
A. Dkiouak

A high order multiple input multiple output (MIMO) antenna assembly is designed for Ultra-Wideband (UWB) applications. The antenna configuration is based on a peculiar arrangement of the radiating elements. A defected microstrip structure is also introduced on the feedlines. The use of a novel technique, the so-called ports-shift, is here discussed. In the proposed antenna, a protruded ground branch structure is employed in combination of three parasitic stubs so as to enhance isolation and impedance matching over the UWB frequency band. The results show that the presented antenna exhibits a good impedance matching which is about -10 dB with a high mutual coupling 15 dB, and envelope correlation coefficients (ECC) smaller than 0.15. The antenna also exhibits good diversity gain of about 9.5, and a good efficiency that varied between 56% and 91% and total active reflection coefficient of less than -20 dB. Which makes it a good candidate for UWB applications.

2021 ◽  
Vol 36 (1) ◽  
pp. 61-66
Author(s):  
Yantao Yu ◽  
Shenshen Mao ◽  
Meng Li ◽  
Danting He

In this paper, a novel compact multiple-input multiple-output (MIMO) antenna with enhanced port isolation is proposed for ultra-wideband (UWB) applications. The UWB MIMO antenna contains two coplanar annular monopoles etched on the front side of the FR-4 substrate. The dielectric substrate has a relative permittivity of 4.4 and a size of 80 mm × 40 mm × 1.6 mm. The irregular ground is printed on the back side of the substrate. In order to enhance the port isolation between the two monopoles, the expanded ground is exploited in the proposed design. In addition, the ground is etched with some slots to achieve good impedance matching. Both the simulated and measured results show that the proposed antenna achieves good impedance matching as well as high port isolation over the entire UWB band. Moreover, the proposed antenna has good spatial diversity characteristics. In summary, the proposed UWB MIMO antenna can be well applied to the ultra-wideband wireless communication system.


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.


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.


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.


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.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2688
Author(s):  
Wenfei Yin ◽  
Shaoxiang Chen ◽  
Junjie Chang ◽  
Chunhua Li ◽  
Salam K. Khamas

In the paper, an extremely compact multiple-input-multiple-output (MIMO) antenna is proposed for portable wireless ultrawideband (UWB) applications. The proposed prototype consists of four monopole antenna elements, which are placed perpendicularly to achieve polarization diversity. In addition, the mutual coupling between antenna elements is suppressed by designing the gap between the radiation element and the ground plane. Moreover, a matching stub has been connected to the feedline to ensure impedance matching in high frequency. Both simulated and measured results indicate that the proposed antenna has a bandwidth of 3–20 GHz, with a high isolation better than 17 dB. In addition, the designed MIMO antenna offers excellent radiation characteristics and stable gain over the whole working band. The envelope correlation coefficient (ECC) is less than 0.1, which shows that the antenna can meet the polarization diversity characteristics well.


Author(s):  
M. Saravanan ◽  
R. Kalidoss ◽  
B. Partibane ◽  
K. S. Vishvaksenan

Abstract The design, analysis, fabrication, and testing of a four-port multiple-input multiple-output (MIMO) antenna is reported in this paper for automotive communications. The MIMO antenna is constructed using the basic antenna element exploiting a slot geometry. Two such antennas are developed on the same microwave laminate to develop a two-port MIMO antenna. Two such microwave laminates are interlocked to create the four-port MIMO scheme. The most distinct feature of the proposed architecture is that the inter-port isolation is well-taken care without the need for an external decoupling unit. The four-port MIMO antenna has an overall volume of 32 × 15 × 32 mm3. The prototype MIMO antenna is fabricated and the measurements are carried out to validate the simulation results. The antenna offers ultra-wideband (UWB) characteristics covering the frequency range of 2.8–9.5 GHz. The average boresight gain of the antenna ranges from 3.2 to 5.41 dBi with the peak gain at 8 GHz. The simulated efficiency of the antenna is greater than 73% within the operating bandwidth. The MIMO parameters such as envelope correlation coefficient, diversity gain, and mean effective gain are evaluated and presented. The appropriateness of the proposed antenna for deployment in the shark fin housing of the present-day automobiles is verified using on-car performance estimation.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yanjie Wu ◽  
Yunliang Long

This paper presents a long-term evolution (LTE) 700 MHz band multiple-input-multiple-output (MIMO) antenna, and high isolation between the two symmetrical antenna elements is obtained without introducing extra decoupling structure. Each antenna element is a combination antenna of PIFA and a meander monopole antenna. The end of the PIFA and the meander monopole antenna are, respectively, overlapped with the 50 Ω microstrip feed line, the two overlapping areas produce additional capacitance which can be considered decoupling structures to enhance the isolation for the MIMO antenna, as well as the impedance matching of the antenna elements. The MIMO antenna is etched on FR4 PCB board with dimensions of 71 × 40 × 1.6 mm3; the edge-to-edge separation of the two antenna elements is only nearly 0.037 λat 700 MHz. Both simulation and measurement results are used to confirm the MIMO antenna performance; the operating bandwidth is 698–750 MHz withS11≤−6 dB andS21≤−23 dB.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8238
Author(s):  
Lekha Kannappan ◽  
Sandeep Kumar Palaniswamy ◽  
Lulu Wang ◽  
Malathi Kanagasabai ◽  
Sachin Kumar ◽  
...  

A quad-element multiple-input-multiple-output (MIMO) antenna with ultra-wideband (UWB) performance is presented in this paper. The MIMO antenna consists of four orthogonally arranged microstrip line-fed hexagonal monopole radiators and a modified ground plane. In addition, E-shaped and G-shaped stubs are added to the radiator to achieve additional resonances at 1.5 GHz and 2.45 GHz. The reliability of the antenna in the automotive environment is investigated, with housing effects taken into account. The housing effects show that the antenna performs consistently even in the presence of a large metal object. The proposed MIMO antenna has potential for various automotive applications, including vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X), intelligent transport system (ITS), automatic vehicle identifier, and RFID-based electronic toll collection.


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