A control strategy for electromagnetic near and far field calculation

Thinning and Weighting of Planar/Conformal Arrays Considering Mutual Coupling Effects

International Journal of Antennas and Propagation ◽

10.1155/2016/7521723 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

You-Feng Cheng ◽

Wei Shao ◽

Ran Zhang ◽

Xiao Ding ◽

Meng-Xia Yu

Keyword(s):

Mutual Coupling ◽

Differential Evolution Algorithm ◽

Far Field ◽

Field Calculation ◽

Sidelobe Suppression ◽

Sparse Arrays ◽

Low Sidelobe ◽

Key Points ◽

Element Pattern ◽

Synthesis Approach

Based on an improved active element pattern (AEP) technique, a novel effective method for sidelobe suppression considering mutual coupling (MC) in planar and conformal sparse arrays is proposed in this paper. A thinning and weighting process that includes the thinning module, optimization module, and far-field calculation module is presented, and three key points, namely, the modified AEP modeling, far-field calculation of planar and conformal thinned arrays, and modified thinning strategy, are highlighted. As an effective optimization algorithm, the differential evolution algorithm (DEA) is adopted in order to achieve low sidelobe. Several numerical examples are shown to validate the consistency and effectiveness of the proposed synthesis approach. With the first use of the AEP technique for the synthesis of sparse arrays, the planar and conformal microstrip arrays with the desired array filling factor are studied to obtain the expected sidelobe level (SLL).

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The lift force on a spherical body in a rotational flow

Journal of Fluid Mechanics ◽

10.1017/s002211208700260x ◽

1987 ◽

Vol 183 ◽

pp. 199-218 ◽

Cited By ~ 321

Author(s):

T. R. Auton

Keyword(s):

Shear Flow ◽

Lift Force ◽

Spherical Body ◽

Inviscid Fluid ◽

Far Field ◽

Rotational Flow ◽

Field Calculation ◽

Sphere Surface ◽

Secondary Velocity

This paper concerns the flow about a sphere placed in a weak shear flow of an inviscid fluid. The secondary velocity resulting from advection of vorticity by the irrotational component of the flow is computed on the sphere surface, and on the upstream axis. The resulting lift force on the sphere is evaluated, and the result is confirmed by an analytical far-field calculation. The displacement of the stagnation streamline, far upstream of the sphere, is calculated more accurately than in previous papers.

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Some advancements in antenna near/far field calculation for EMC prediction

The 2006 4th Asia-Pacific Conference on Environmental Electromagnetics ◽

10.1109/ceem.2006.257899 ◽

2006 ◽

Cited By ~ 1

Author(s):

Ben-qing Gao ◽

Jang-dong Geng ◽

Wei-min Li

Keyword(s):

Far Field ◽

Field Calculation

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Substituting EMC emission measurement by field and cable scan method using measured transfer function

Advances in Radio Science ◽

10.5194/ars-11-183-2013 ◽

2013 ◽

Vol 11 ◽

pp. 183-188 ◽

Cited By ~ 2

Author(s):

D. Rinas ◽

J. Jia ◽

A. Zeichner ◽

S. Frei

Keyword(s):

Transfer Functions ◽

Near Field ◽

Good Alternative ◽

Emission Measurement ◽

Far Field ◽

Field Calculation ◽

Automotive Components ◽

Anechoic Chambers ◽

Cispr 25 ◽

Space Requirements

Abstract. Today EMC emissions of automotive components are often measured in anechoic chambers by an antenna at fixed position according to CISPR 25 (ALSE-method). The antenna voltage often cannot sufficiently describe the behaviour of the measured electronic components and systems. Furthermore space requirements and costs are very high for the ALSE-method. Field- and cable-scan methods combined with near-field to far-field transformation techniques might be a good alternative. Residual reflections from the walls, the metallic floor, the measuring table, interaction of the antenna with the environment, and other factors affect the measurements. Thus, models which only regard the current distribution for near- and far field calculation cannot produce results equal to a chamber measurement. In this paper methods for computing transfer functions for the substitution of EMC antenna measurements with field- and cable scans in a specified calibration area are introduced. To consider influences of the environment, the environment is characterized in a first step and included with transfer functions in the calculation process for the equivalent ALSE-field.

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