Influence of the Aperture Edge Diffraction Effects on the Mutual Coupling Compensation Technique in Small Planar Antenna Arrays

2011 ◽  
Vol 57 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Mariusz Zamłyński ◽  
Piotr Słobodzian
Keyword(s):  
Antenna Arrays ◽  
Mutual Coupling ◽  
Planar Antenna ◽  
Sidelobe Level ◽  
Edge Diffraction ◽  
Narrow Angle ◽  
Compensation Technique ◽  
Diffraction Effects ◽  
Linear Antenna Arrays

Influence of the Aperture Edge Diffraction Effects on the Mutual Coupling Compensation Technique in Small Planar Antenna Arrays In this paper the quality of a technique to compensate for mutual coupling (and other phenomena) in small linear antenna arrays is investigated. The technique consists in calculation of a coupling matrix, which is than used to determine corrected antenna array excitation coefficients. Although the technique is known for more than 20 years, there is still very little information about how different phenomena existing in a real antenna arrays influence its performance. In this paper two models of antenna arrays are used. In the first model the effect of mutual coupling is separated from the aperture edge diffraction. In the second model antenna both mutual coupling and aperture edge diffraction effects are included. It is shown that mutual coupling itself can be compensated very well and an ultralow sidelobe level (i.e. -50 dB) could be achieved in practice. In the presence of diffraction effects -46.3 dB sidelobe level has been attained, but radiation pattern can be controled only in narrow angle range (i.e. up to ±60°).

Mutual coupling effects in linear antenna arrays

1970 ◽  
Vol 48 (6) ◽  
pp. 659-674 ◽  
Author(s):  
A. L. VanKoughnett
Keyword(s):  
Integral Equations ◽  
Antenna Arrays ◽  
Mutual Coupling ◽  
Linear Antenna ◽  
Coupling Effects ◽  
Mutual Impedance ◽  
Impedance Characteristics ◽  
Linear Antenna Arrays

The effects of mutual coupling among the array elements on the pattern and impedance characteristics of linear antenna arrays are examined. Based upon the assumption that the mutual impedance of two array elements depends only upon the separation of the elements, exact expressions are derived for the properties of infinite and semi-infinite arrays. Integral equations which describe finite arrays are derived and solved for special forms of the mutual impedance behavior and for large arrays.

scholarly journals Bandwidth Enhancement of Antenna Arrays Utilizing Mutual Coupling between Antenna Elements

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Min Wang ◽  
Wen Wu ◽  
Zhongxiang Shen
Keyword(s):  
Reflection Coefficient ◽  
Antenna Arrays ◽  
Mutual Coupling ◽  
Coupling Effect ◽  
Approximate Expression ◽  
Scattering Parameters ◽  
Linear Superposition ◽  
Bandwidth Enhancement ◽  
Slot Arrays ◽  
Linear Antenna Arrays

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.

scholarly journals Optimized Hyper Beamforming of Linear Antenna Arrays Using Collective Animal Behaviour

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Gopi Ram ◽  
Durbadal Mandal ◽  
Rajib Kar ◽  
Sakti Prasad Ghoshal
Keyword(s):  
Antenna Arrays ◽  
Optimization Technique ◽  
Optimal Solution ◽  
Beam Width ◽  
Animal Behaviour ◽  
Linear Antenna ◽  
Sidelobe Level ◽  
Real Coded Genetic Algorithm ◽  
Linear Antenna Arrays ◽  
Collective Animal Behaviour

A novel optimization technique which is developed on mimicking the collective animal behaviour (CAB) is applied for the optimal design of hyper beamforming of linear antenna arrays. Hyper beamforming is based on sum and difference beam patterns of the array, each raised to the power of a hyperbeam exponent parameter. The optimized hyperbeam is achieved by optimization of current excitation weights and uniform interelement spacing. As compared to conventional hyper beamforming of linear antenna array, real coded genetic algorithm (RGA), particle swarm optimization (PSO), and differential evolution (DE) applied to the hyper beam of the same array can achieve reduction in sidelobe level (SLL) and same or less first null beam width (FNBW), keeping the same value of hyperbeam exponent. Again, further reductions of sidelobe level (SLL) and first null beam width (FNBW) have been achieved by the proposed collective animal behaviour (CAB) algorithm. CAB finds near global optimal solution unlike RGA, PSO, and DE in the present problem. The above comparative optimization is illustrated through 10-, 14-, and 20-element linear antenna arrays to establish the optimization efficacy of CAB.

scholarly journals A Feeding Network with Chebyshev Distribution for Designing Low Side-lobe Level Antenna Arrays

2017 ◽  
Author(s):  
Toan The Tang ◽  
Tran Minh Nguyen ◽  
Giang Truong Vu Bang
Keyword(s):  
Antenna Arrays ◽  
Linear Array ◽  
Side Lobe ◽  
Power Divider ◽  
Side Lobe Level ◽  
Linear Antenna ◽  
Sidelobe Level ◽  
Weighting Method ◽  
Low Sidelobe ◽  
Linear Antenna Arrays

This paper proposes a feeding networking to gain low sidelobe levels for microstrip linear antenna arrays. The procedure to design a feeding network using Chebyshev weighting method will be proposed and presented. As a demonstration, a feeding network for 8×1 elements linear array with Chebyshev distribution weights (preset sidelobe level of -25 dB) has been designed. An unequal T-junction power divider has been applied in designing the feeding network to guarantee the output powers the same as Chebyshev weights. The obtained results of the amplitudes at each output port have been validated with theory data. The phases of output signals are almost equal at all ports. The proposed feeding network, therefore, can be a good candidate for constructing a low sidelobe level linear array antenna.

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