Multiple-input multiple-output ultra-wide band channel modelling method based on ray tracing

2012 ◽  
Vol 6 (10) ◽  
pp. 1195 ◽  
Author(s):  
H.M. Asif ◽  
B. Honary ◽  
H. Ahmed
2018 ◽  
Vol 7 (4) ◽  
pp. 46-70 ◽  
Author(s):  
I. Gnanaharan ◽  
R. Anbazhagan

Ultra wide band - Multiple Input Multiple Output antenna technology provides higher data rates and the combination of the ultra wide band (UWB) and the multiple input multiple output (MIMO) technologies provides a solution for the demand of still higher data rates i.e. in excess of 3 Gb/sec in the future.  As the antenna technologies are improving, the size of the MIMO antenna is growing smaller and smaller. Placing the antenna elements in such close proximity increases the coupling between them. Various isolation techniques have to be introduced between the antenna elements to decrease the coupling and to improve the isolation. A study of the various isolation enhancement techniques have been made in this review. It analyses the various isolation enhancement methods such as using orthogonal polarization, parasitic elements, varied decoupling structures, defected ground structures (DGS), neutralization line (NL) and finally by using metamaterials. Metamaterials is a technology to perk up the isolation between the antenna elements. Split ring resonator (SRR) behaves as a metamaterial and it is used as an isolation mechanism in this study. The antennas are simulated and the results are compared. The method using parasitic elements gives the highest isolation of 35 dB and it is 5 dB better than the methods using orthogonal polarization and using the decoupling structure. The performance of all the antennas satisfies the conditions for minimum isolation. The envelope correlation coefficient is nearly zero in all the antennas and it implies good diversity performance. The diversity gain is also calculated for the various antennas and it satisfies good diversity performance. The bandwidth of the antennas is in the UWB frequency range and they have a fractional bandwidth above the required value of 1.09. The capacity loss for all the antennas is very low and the antennas using defected ground structure and the decoupling structure gives very low capacity loss.


2018 ◽  
Vol 11 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Sanjay Chouhan ◽  
Debendra Kumar Panda ◽  
Vivek Singh Kushwah ◽  
Pankaj Kumar Mishra

AbstractA four-element wide-band octagonal ring-shaped antenna is proposed for human interface device and S-band applications. The isolation structure comprises a parasitic element and a T-shaped structure. The antenna has −10 dB impedance bandwidth 63% (2.1–4.0 GHz) with miniaturized dimension of 54.98 mm × 76 mm. The multiple input multiple output (MIMO) antenna gain is 2.83 dBi at the 2.4 GHz resonant frequency. The designed MIMO has envelop correlation coefficient of 0.026 in the 2:1 VSWR band. The −10 dB total active reflection coefficient bandwidth of 1.2 GHz has been achieved in the entire frequency band, and has MEG value of ≤−3 dB. The specific absorption rate has found below the safety limit near the human head, palm and wrist.


2021 ◽  
Vol 20 ◽  
pp. 146-151
Author(s):  
Edgar Alejandro Andrade-Gonzalez ◽  
Juan Carlos Ordoñez-Martínez ◽  
Mario Reyes-Ayala ◽  
José Alfredo Tirado Méndez ◽  
Hilario Terres-Peña

In this article, a compact ultra-wide band (UWB) multiple input multiple output (MIMO) antenna system is showed. This antenna is based on fractal Fibonacci circles and operates over wide frequency range from 2.9 to 14.51 GHz. The dielectric used was Duroid substrate with dielectric constant εr = 2.2 and thickness of substrate 1.27 mm. This UWB MIMO antenna is simulated by HFSS. In order to improve the isolation between the elements of the antenna a parasitic structure is used, getting S12 and very low ECC. Also, the Total Active reflection Coefficient (TARC) was obtained. Proposed antenna can be used for UWB communication applications and its size is 64 × 38mm2


Frequenz ◽  
2018 ◽  
Vol 72 (11-12) ◽  
pp. 503-509
Author(s):  
Rohit Mathur ◽  
Santanu Dwari

Abstract A compact 4-port ultra-wide band (UWB) multiple-input-multiple-output (MIMO) slot antenna with dual polarization is presented. The key features of antenna are: has directive radiation in two planes and low correlation without use of additional decoupling structure. The antenna contains four microstrip feedlines having circular patches backed by stepped circular slots. Orthogonal arrangement of each slot antenna increases compactness with polarization diversity and good isolation. The antenna has compact size of 36×36×0.8 mm3. It operates in the frequency band of 3.1 to 11.9 GHz and isolation is better than 15 dB. The superior diversity performance is ensured by calculating envelope correlation coefficient (ECC) and diversity gain. In addition to guarantee distortion less transmission in UWB group delay is also measured.


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