scholarly journals Parametric Analysis of Linear Periodic Arrays Generating Flat-Top Beams

Electronics ◽  
2021 ◽  
Vol 10 (20) ◽  
pp. 2452
Author(s):  
Piero Angeletti ◽  
Giulia Buttazzoni ◽  
Giovanni Toso ◽  
Roberto Vescovo
Keyword(s):  
Linear Programming ◽  
Parametric Analysis ◽  
Beam Width ◽  
Side Lobe ◽  
Design Parameters ◽  
Linear Arrays ◽  
Periodic Arrays ◽  
Array Antennas ◽  
Periodic Linear ◽  
Programming Techniques

Several synthesis techniques are available to optimize amplitude and phase excitations of periodic linear arrays to generate flat-top beams. Clearly, the optimal tapering depends on design parameters such as the array length, the number of array elements, the beam flatness, the beam width, the side lobe levels, and others. In this paper, in order to derive useful guidelines and rule of thumb for the synthesis of periodic array antennas, relations between these parameters are derived employing linear programming techniques, which guarantee optimality of the solutions. Such relations are then plotted and used in some design examples.

scholarly journals Design and Analysis of Novel Fractal Linear and Planar Array Antennas for Satellite Applications

2016 ◽  
Vol 5 (3) ◽  
pp. 56 ◽  
Author(s):  
V. A. Sankar ◽  
P. V. Y. Jayasree
Keyword(s):  
Design Methodology ◽  
Beam Width ◽  
Side Lobe ◽  
Circular Ring ◽  
Geometric Design ◽  
Side Lobe Level ◽  
Array Antennas ◽  
Repetitive Nature ◽  
Satellite Applications ◽  
Planar Array

This article proposed a new geometric design methodology for the systematic expansion of fractal linear and planar array antennas. Using this proposed geometric design methodology any deterministic polygon shape can be constructed. In this article, two element fractal linear and triangular array antennas are examined using proposed methodology up to four iterations of two expansion factors. Due to the repetitive nature of the proposed geometric design methodology, both linear and planar fractal arrays shows multi-beam behavior with excellent array factor properties. The behavior of the proposed arrays shows better performance than linear and planar fractal array antennas generated by concentric circular ring sub array geometric generator. Triangular planar fractal array of expansion factor two at fourth iteration achieved a single valued beam width of 3.80 with -31.6 side lobe level. The suggested fractal arrays are analyzed and simulated by MATLAB-13 programming.

Effects of Spacing and Number of Elements on the Fields Radiated by Linear Arrays of Equally Spaced Elements

2017 ◽  
Vol 2 (9) ◽  
pp. 17-22 ◽  
Author(s):  
Raji A. Abimbola
Keyword(s):  
Electric Field ◽  
Current Distribution ◽  
Beam Width ◽  
Side Lobe ◽  
Main Lobe ◽  
Linear Antenna ◽  
Linear Arrays ◽  
Field Patterns ◽  
Sinusoidal Current

This paper examines the effects of spacings and number of elements on the radiation features of linear antenna of uniformly spaced elements, oriented in end fire directions. Use is made of pattern multiplication concept to evaluate the electric field radiated by the antenna when excited with sinusoidal current distribution. It is found that, when the spacings between the elements of the array are , and , respectively, the radiated field patterns of models of the array depict radiations in broadside and end fire directions while at lower spacings of and , radiations exist only along the end fire directions. In addition, it is also observed that, the beam-width of the main lobe of the field patterns reduces as the spacing and number of element increase which suggests better directivity. However, the improvement in the directivity is followed with side lobe levels which seem to be the disadvantage of that benefit. Furthermore, it is discovered that the array factor patterns and radiated electric field patterns of the antenna display characteristics that are largely similar.

scholarly journals A New Approach for Design Optimization and Parametric Analysis of Symmetric Compound Parabolic Concentrator for Photovoltaic Applications

2021 ◽  
Vol 13 (9) ◽  
pp. 4606
Author(s):  
Faisal Masood ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Javed Akhter ◽  
Mohammad Azad Alam
Keyword(s):  
Parametric Analysis ◽  
Concentration Ratio ◽  
Synergistic Effects ◽  
Geometric Optimization ◽  
Design Parameters ◽  
Imaging Device ◽  
Compound Parabolic Concentrator ◽  
Photovoltaic Applications ◽  
Half Angle ◽  
The Impact

A compound parabolic concentrator (CPC) is a non-imaging device generally used in PV, thermal, or PV/thermal hybrid systems for the concentration of solar radiation on the target surface. This paper presents the geometric design, statistical modeling, parametric analysis, and geometric optimization of a two-dimensional low concentration symmetric compound parabolic concentrator for potential use in building-integrated and rooftop photovoltaic applications. The CPC was initially designed for a concentration ratio of “2×” and an acceptance half-angle of 30°. A MATLAB code was developed in house to provoke the CPC reflector’s profile. The height, aperture width, and concentration ratios were computed for different acceptance half-angles and receiver widths. The interdependence of optical concentration ratio and acceptance half-angle was demonstrated for a wide span of acceptance half-angles. The impact of the truncation ratio on the geometric parameters was investigated to identify the optimum truncation position. The profile of truncated CPC for different truncation positions was compared with full CPC. A detailed statistical analysis was performed to analyze the synergistic effects of independent design parameters on the responses using the response surface modeling approach. A set of optimized design parameters was obtained by establishing specified optimization criteria. A 50% truncated CPC with an acceptance half-angle of 21.58° and receiver width of 193.98 mm resulted in optimum geometric dimensions.

Linear Programming Techniques for the Construction of Palatable Human Diets

1994 ◽  
Vol 45 (5) ◽  
pp. 489-496 ◽  
Author(s):  
L. R. Fletcher ◽  
P. M. Soden ◽  
A. S. I. Zinober
Keyword(s):  
Linear Programming ◽  
Programming Techniques

Synthesis of the internal parallel cam mechanism

1998 ◽  
Vol 212 (7) ◽  
pp. 577-585 ◽  
Author(s):  
M Nishioka ◽  
T Nishimura
Keyword(s):  
Parametric Analysis ◽  
Parallel Mechanism ◽  
Design Parameters ◽  
Cam Mechanism ◽  
Pressure Angle

Parallel cam mechanisms have been studied in different ways. In this paper, a parametric formulation which can cover every configuration of the parallel cam mechanism is derived. As a result of parametric analysis, a new, last mechanism was found. This cam is essentially an internal cam mechanism. Based on the assumption of an equally distributed roller follower, the basic configurations of the mechanism are derived from both the pressure angle and the undercutting constraints. As a result, the possible number of rollers per spider plate is two. Thus the feasible area of the design parameters of the mechanisms are obtained. The advantages of the mechanism over the conventional parallel mechanism are the saving of space and a larger angular stroke of output.

An Integer Linear Programming-Based Method for the Extraction of Ontology Alignment

2021 ◽  
Vol 16 (2) ◽  
pp. 25-44
Author(s):  
Naima El Ghandour ◽  
Moussa Benaissa ◽  
Yahia Lebbah
Keyword(s):  
Linear Programming ◽  
Semantic Web ◽  
Integer Linear Programming ◽  
New Method ◽  
Ontology Matching ◽  
Ontology Alignment ◽  
Programming Techniques ◽  
Data Heterogeneity ◽  
Series Of Experiments

The Semantic Web uses ontologies to cope with the data heterogeneity problem. However, ontologies become themselves heterogeneous; this heterogeneity may occur at the syntactic, terminological, conceptual, and semantic levels. To solve this problem, alignments between entities of ontologies must be identified. This process is called ontology matching. In this paper, the authors propose a new method to extract alignment with multiple cardinalities using integer linear programming techniques. The authors conducted a series of experiments and compared them with currently used methods. The obtained results show the efficiency of the proposed method.

A Comparison of Swarm-Based Optimization Algorithms in Linear Antenna Array Synthesis

2021 ◽  
Author(s):  
Ali Durmus ◽  
Rifat KURBAN ◽  
Ercan KARAKOSE
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Heuristic Algorithms ◽  
Beam Width ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Linear Antenna ◽  
Half Power ◽  
Antenna Array Synthesis

Abstract Today, the design of antenna arrays is very important in providing effective and efficient wireless communication. The purpose of antenna array synthesis is to obtain a radiation pattern with low side lobe level (SLL) at a desired half power beam width (HPBW) in far-field. The amplitude and position values ​​of the array elements can be optimized to obtain a radiation pattern with suppressed SLLs. In this paper swarm-based meta-heuristic algorithms such as Particle Swarm Optimization (PSO), Artificial Bee Colony (ABC), Mayfly algorithm (MA) and Jellyfish Search (JS) algorithms are compared to realize optimal design of linear antenna arrays. Extensive experiments are conducted on designing 10, 16, 24 and 32-element linear arrays by determining the amplitude and positions. Experiments are repeated 30 times due to the random nature of swarm-based optimizers and statistical results show that performance of the novel algorithms, MA and JS, are better than well-known methods PSO and ABC.

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