scholarly journals Printed Closely Spaced Antennas Loaded by Linear Stubs in a MIMO Style for Portable Wireless Electronic Devices

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2848
Author(s):  
Aqeel Ahmed Khan ◽  
Muhammad Saeed Khan ◽  
Syed Aftab Naqvi ◽  
Bilal Ijaz ◽  
Muhammad Asif ◽  
...  

An easy-to-manufacture and efficient four-port-printed Multiple Input Multiple Output (MIMO) antenna operating across an ultra-wideband (UWB) region (2.9–13.6 GHz) is proposed and investigated here. The phenomenon of the polarization diversity is used to improve the isolation between MIMO antenna elements by deploying four orthogonal antenna elements. The proposed printed antenna (40 × 40 × 1.524 mm3) is made compact by optimizing the circular-shaped radiating components via vertical stubs on top of the initial design to maximally reduce unwanted interaction while placing them together in proximity. The measurements of the prototype MIMO antennas corroborate the simulation performance. The findings are compared to the recent relevant works presented in the literature to show that the proposed antenna is suitable for UWB MIMO applications. The proposed printed UWB MIMO antenna could be a good fit for compact portable wireless electronic devices.

Author(s):  
Zhonghong Du ◽  
Xiaohui Zhang ◽  
Peiyu Qin ◽  
Yanning Yuan ◽  
Jiangfan Liu ◽  
...  

Abstract A compact four-element ultra-wideband (UWB) multiple-input–multiple-output (MIMO) antenna with dual polarization and dual-notched capabilities was developed and fabricated. The MIMO antenna is composed of four orthogonally placed half-cutting UWB antenna elements. This orthogonal placement improves the isolation. Furthermore, an L-shaped slot and a continuous bending slot are etched to realize the band-rejection function in the WiMAX and WLAN bands. The result shows that the antenna achieved operating bands of 2.9–16.5 GHz (140.2%, S11 < −10 dB), fully covering the UWB (3.1–10.6 GHz). The port isolation is greater than 23 dB in the frequency band of interest, excluding two rejected bands. Moreover, the MIMO antenna has excellent diversity performance, such as a low envelope correlation coefficient (<0.004), high diversity gain (approximately 10 dB), and good omnidirectional radiation characteristics.


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).


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.


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.


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.


2010 ◽  
Vol 2 (3-4) ◽  
pp. 369-377 ◽  
Author(s):  
Timofey Savelyev ◽  
Xiaodong Zhuge ◽  
Bill Yang ◽  
Pascal Aubry ◽  
Alexander Yarovoy ◽  
...  

This paper presents an experimental investigation of two approaches to short-range radar imaging at microwaves by means of ultra-wideband (UWB) technology. The first approach represents a classical synthetic aperture radar (SAR) that employs a transmit–receive antenna pair on mechanical scanner. The second one makes use of a multiple input multiple output (MIMO) antenna array that scans electronically in the horizontal plane and mechanically, installed on the scanner, in the vertical plane. The mechanical scanning in only one direction reduces significantly the measurement time. Two respective prototypes have been built and compared. Both systems comprise the same 10–18 GHz antennas and multi-channel video impulse electronics while the same data processing and imaging method based on Kirchhoff migration is applied to acquired data for digital beamforming. The study has been done for an application of concealed weapon detection.


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 (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.


2019 ◽  
Vol 8 (3) ◽  
pp. 6-15
Author(s):  
A. Chaabane ◽  
A. Babouri

This paper introduces a novel compact planar Ultra-Wideband (UWB) Multiple-Input-Multiple-Output (MIMO) antenna with dual-band notched performance for Surfaces Penetrating (SP) application. To avoid interference from co-existing systems, two notched bands are introduced by including strips inside the radiating patches. The two ports MIMO antenna is printed on the low-cost FR4 substrate having a compact size of 56×32.47×1.5 mm3. The measured results indicate that the −10 dB bandwidth of the proposed MIMO antenna covers a wide bandwidth from 1.57 GHz to 12.4 GHz (155.05%) with dual-band rejection (2.04 GHz – 3.98 GHz and 4.8 GHz – 6.22 GHz). The effects of numerous construction and decoration surfaces on the antenna’s reflection coefficients are measured. Gypsum, White Portland Cement, Slate, Marble, Wood and Reinforced Concrete were tested. A good penetrating capability is measured which confirms the aptitude of the proposed MIMO antenna to work as SP antenna.


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.


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