On the effects of mutual coupling in the active reflection coefficient of wide-field scanning electrically large random phased arrays

Author(s):  
Eloy de Lera Acedo ◽  
Michel Arts ◽  
Christophe Craeye ◽  
Ha Bui Van
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.


2013 ◽  
Vol 2013 ◽  
pp. 1-23 ◽  
Author(s):  
Hema Singh ◽  
H. L. Sneha ◽  
R. M. Jha

The mutual coupling between antenna elements affects the antenna parameters like terminal impedances, reflection coefficients and hence the antenna array performance in terms of radiation characteristics, output signal-to-interference noise ratio (SINR), and radar cross section (RCS). This coupling effect is also known to directly or indirectly influence the steady state and transient response, the resolution capability, interference rejection, and direction-of-arrival (DOA) estimation competence of the array. Researchers have proposed several techniques and designs for optimal performance of phased array in a given signal environment, counteracting the coupling effect. This paper presents a comprehensive review of the methods that model and mitigate the mutual coupling effect for different types of arrays. The parameters that get affected due to the presence of coupling thereby degrading the array performance are discussed. The techniques for optimization of the antenna characteristics in the presence of coupling are also included.


Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1265
Author(s):  
Haoran Xing ◽  
Xinyan Wang ◽  
Zhenbin Gao ◽  
Xing An ◽  
Hong-xing Zheng ◽  
...  

To implement efficient isolation between units of a multi-input multi-output (MIMO) antenna, a defected ground structure (DGS) has been investigated. An antenna with two elements operating at 5.8 GHz and fed by coaxial is considered. To reduce mutual coupling between the elements, a zigzag groove is inserted into the center of two elements formed as a DGS. To verify this design, a scattering matrix was tested, such as reflection coefficient S11 and transmission coefficient S21 between two element ports. Meanwhile, radiation pattern, current distribution, envelope correlation coefficient (ECC), and diversity gain of the antenna were simulated and measured. The results showed that the mutual coupling was reduced by 28.8 dB when a DGS was used, and the ECC was less than 0.02. Owing to these good performances, each antenna element can operate almost independently, and this MIMO antenna can be efficiently applied to the narrow band Internet of Things system.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Min Wang ◽  
Wen Wu ◽  
Zhongxiang Shen

The mutual coupling effect between antenna elements on an array's bandwidth is investigated using scattering parameters instead of the mutual impedance. First, an approximate expression is derived for matched voltage standing wave ratio (VSWR) bandwidth of a tuned antenna, which reveals that the bandwidth is inversely proportional to the magnitude|Γ0'(ω0)|of the frequency derivative of the reflection coefficient. Next, considering linear antenna arrays with corporate feed as an example, closed-form expressions of the reflection coefficient are derived at the input port of the feeding network, which shows that the active reflection coefficient of an array is the linear superposition of elements' passive reflection coefficientS11and the mutual coupling coefficientS12from adjacent elements. The VSWR bandwidth expressions for an array imply that bandwidth enhancement of the overall array can be achieved when the element passive reflection coefficientS11and mutual couplingS12are cancelled, as well as the frequency derivativesS11'andS12'also cancel each other. Slot arrays and a two-element Vivaldi array are investigated to verify the validity of our theoretical analysis. Numerical and experimental results are presented to successfully demonstrate the bandwidth enhancement of antenna arrays utilizing mutual coupling effect.


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