Slot arrays on single-hard-wall waveguides: A study of slot mutual coupling using the aperture integral equation

2010 ◽  
Author(s):  
E Alfonso ◽  
A Valero-Nogueira ◽  
J I Herranz ◽  
F Vico
Keyword(s):  
Integral Equation ◽  
Mutual Coupling ◽  
Hard Wall ◽  
Slot 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.

The design of slot arrays including internal mutual coupling

1986 ◽  
Vol 34 (9) ◽  
pp. 1149-1154 ◽  
Author(s):  
R. Elliott ◽  
W. O'Loughlin
Keyword(s):  
Mutual Coupling ◽  
Slot Arrays

scholarly journals Efficient Evaluation of the External Mutual Coupling in Dielectric-Covered Waveguide Slot Arrays

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Zusheng Jin ◽  
Giorgio Montisci ◽  
Giovanni Andrea Casula ◽  
Hu Yang ◽  
Junqi Lu
Keyword(s):  
Mutual Coupling ◽  
Computation Time ◽  
Direct Calculation ◽  
Spatial Domain ◽  
Image Method ◽  
Efficient Procedure ◽  
Planar Arrays ◽  
Complex Image ◽  
Slot Arrays ◽  
Discrete Complex Image Method

An accurate and efficient procedure is devised to evaluate the mutual coupling in dielectric-covered planar arrays of longitudinal slots. This approach takes full advantage of the discrete complex image method to cast the spatial-domain Green's functions into closed forms, and hence a direct calculation of mutual coupling in the spatial-domain is available. The computation time reduces significantly compared to the previous spectral-domain procedure, without any loss in the accuracy, rendering this approach very attractive for the design of large dielectric-covered planar arrays.

DENSITY PROFILES OF A HARD GAUSSIAN OVERLAP FLUID BETWEEN HARD WALLS

2005 ◽  
Vol 19 (10) ◽  
pp. 1717-1729 ◽  
Author(s):  
M. MORADI ◽  
A. AVAZPOUR
Keyword(s):  
Density Functional Theory ◽  
Integral Equation ◽  
Correlation Function ◽  
Density Functional ◽  
Direct Correlation Function ◽  
Hard Wall ◽  
Density Profiles ◽  
Functional Theory ◽  
Orientation Model ◽  
The Density Functional Theory

The density profiles of a hard Gaussian overlap (HGO) fluid confined in between hard walls and in contact with a hard wall are studied using the density functional theory. The hyper-netted chain (HNC) approximation is used to find the coupled integral equations for the density profiles. The restricted orientation model (ROM) is used. The required homogeneous direct correlation function (DCF) is obtained by solving Ornstein–Zernike (OZ) integral equation numerically, using the Precus–Yevick (PY) approximation and the procedure mentioned by Letz and Latz [Phys. Rev.E60, 5865 (1999)]. We also obtained the DCF of hard ellipsoidal (HE) fluid by using the modified closest approach introduced by Rickayzen [Mol. Phys.68, 903 (1989)]. For both HGO and HE, we calculate the density profiles of molecules parallel and perpendicular to the walls and we compare the results. The calculations are performed for various values of packing fractions of the fluid and various molecular elongations. For moderate elongations, k≤3, the results for HGO and HE are almost the same, especially for the density profile of the molecules parallel to the walls but for k=5 there are some discrepancies between the results, in particular for the density profiles of the molecules perpendicular to the walls.

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