First Null Beam Width Research Articles

Synthesis of elliptical cylindrical antenna array using craziness particle swarm optimization for suppressing sidelobe level

This paper introduces Craziness-based particle swarm optimization (CRPSO), an enhanced Particle Swarm Optimization method, to study the best antenna design for an Elliptical Cylindrical Array (ECA). Heuristic methods such as the PSO algorithm has two key benefits: it employs minimal control parameters and converges quickly. However, PSO performance can be, hampered by early convergence and stagnation. This study modifies the PSO algorithm to address these issues by a “craziness” factor represented by a craziness variable. The CRPSO approach to minimizing the Side Lobe Level (SLL) by determining the optimal configuration of active and inactive elements without preset, First Null Beam Width (FNBW) parameters. Additionally, SLL variation with various element spacings. Results show a significant decrease in SLL up to −42.83 dB, and comparing the results to PSO and existing literature shows superior SLL reduction.

Design of a Circular Micro-strip Patch Antenna for Improved Directivity and Gain of Mobile Communication Base Station

This study presents the design of Circular Micro-strip Patch Antenna (CMPA) for improved directivity and gain of mobile communication base station. The design incorporates a Rogger/5880 substrate material with a permittivity of 2.2, tangent angle of 0.00009 and a substrate height (thickness) of 0.98μm at a frequency of 1.65THz. Diversity Antenna Array Processing (DAAP) and Chebyshev Antenna Array (CAA) methods were used in the design. AutoCAD software and 2D data plotter were used for the diagrams and charts while Maple software was used for simulation. For angles of 0o, 30o, 60o, 90o, 120o, 150o and 180o, the array factors are 7.84dB, 7.85dB, 7.87dB, 7.88dB, 7.87dB, 7.85dB and 7.84db respectively. The results from the design demonstrated a remarkably low side lobe level of 0.01dB, indicating excellent suppression of unwanted radiation in undesired directions. Additionally, the antenna exhibits a Voltage Standing Wave Ratio (VSWR) of unity, ensuring maximum power transfer efficiency from the source to the load. Furthermore, the antenna shows a high directivity and gain of approximately 9dB, which enhances the signal strength and coverage range. The Half Power Beam-width (HPBW) and First Null Beam-width (FNBW) was measured as 300 and 600 respectively. These parameters depict the angular width of the main radiation beam and the sharpness of the beam pattern’s nulls. In all, the designed CMPA with its CAA based antenna array holds great potential for communication networks and for mobile communication base station, offering enhanced performance in terms of radiation characteristics and signal quality.

Optimal pattern synthesis of circular antenna arrays with improved effective aperture and beam area

Abstract Circular antenna array (CAA) is one of the most widely used antenna array designs. This paper addresses the design challenges of the CAA with the non-uniform single ring, which is placed in an X-Y plane with the best sidelobe level (SLL) and improved first null beamwidth (FNBW). It has been solved using differential evolution, craziness-based particle swarm optimization (CRPSO), and novel particle swarm optimization (NPSO) techniques. An optimal combination of feeding current and inter-element spacing provides an array pattern with the best SLL and improved FNBW, as well as some other parameter calculations of the antenna array like maximum directivity, maximum effective aperture, total effective aperture, maximum beam area, total beam area, circumference, and radius of the CAAs using these techniques. There are six designs of CAAs with different antenna elements (i.e., 10-, 12-, 16-, 20-, 36-, and 64-elements) which have been taken into account. Simulations are done in MATLAB. Based on various simulation results, we can analyze the performance of SLL and FNBW with other parameters using NPSO and compare them with different techniques of CAAs, as shown in the numerical analysis and simulation result section.

The Optimum Design of Scanned Linear Antenna Array Using Sine Cosine Optimization Algorithm

In this article, the side lobe level (SLL) of the radiation pattern is reduced, and the first null beam width (FNBW) is kept constant by synthesizing symmetric scanning Linear Antenna Arrays (LAA), which is done by considering excitation amplitude as the optimization parameter. A Sine cosine algorithm (SCA) is used to achieve this objective. Three different case studies are illustratedin this article to show the effectiveness of SCA in LAA optimization. The results obtained show that the SCA algorithm performs better than Firefly Algorithm (FA), Symbiotic Organisms Search (SOS), and hybrid optimization algorithm based on Grasshopper Optimization Algorithm (GOA) and Antlion Optimization (ALO)

Approximating the pareto fronts for synthesis of planar antenna array using binary cat swarm optimization algorithm

Various performance indices like peak sidelobe level (PSLL), first null beamwidth (FNBW) and count of elements contrast to each other while designing an antenna array. A swarm-based intelligence mechanism has been discussed here for optimizing these performance indices. In particular, a pareto front is approximated for bringing out the best compromised array performance having low PSLL with narrow FNBW while maintaining a smaller number of antenna elements. A thinned planar antenna array of 20×10 was synthesized using multi-objective modified binary cat swarm optimization (MO-BCSO) algorithm to obtain the optimal positions of the array elements. The indicated technique is most appropriate for the synthesis of large antenna arrays.

Conflicting Parameter Pair Optimization for Linear Aperiodic Antenna Array using Chebyshev Taper based Genetic Algorithm

In this study, the peak side lobe level (PSLL) in the radiation pattern of a linear antenna array (LAA) is lowered without affecting its first null beam width (FNBW). Antenna array synthesis is commonly applied to achieve high directivity, low side lobes, high gain and desired null positions in the output radiation pattern. But output parameters like PSLL, null positions and beam width conflict with each other, i.e. as one parameter improves, the other deteriorates. To avoid this problem, a multi-objective optimization algorithm can be implemented, in which both the conflicting parameters can be simultaneously optimized. This work proposes a multi-objective algorithm, which takes advantages of the well-known Chebyshev tapering and genetic algorithm (GA), to lower the PSLL without broadening the beam further. Array elements are fed using Chebyshev tapered excitations while GA is incorporated to optimize the elemental spacing. The results of 28-element LAA are compared with those of multi-objective Cauchy mutated cat swarm optimization (MO-CMCSO) existing in literature, which has also been proven to be superior to multi-objective cat swarm optimization (MO-CSO) and multi-objective particle swarm optimization (MO-PSO). Results indicate that the proposed algorithm performs better by further reducing the PSLL from -21.57 dB (MO-CMCSO) to -28.18 dB, while maintaining the same FNBW of 7.4 degrees.

Synthesizing of concentric circular antenna arrays by using a combination of ant lion optimizer and sequential quadratic programming

AbstractAntenna array synthesis is quite a popular topic in electromagnetics and finding suitable array parameter values is a challenging nonlinear engineering problem in this field. In recent years, it has been realized that optimization algorithms can be used to achieve desired solutions in this area. Besides, improvements in the optimization algorithms make it possible to perform synthesis processes on different array structures and to obtain better results. In this paper, a method based on a combination of ant lion optimizer (ALO) and sequential quadratic programming (SQP) is proposed for the concentric circular antenna array (CCAA) synthesis. Excitation amplitudes of array elements are optimized for CCAAs with low maximum sidelobe level (MSL), narrow first null beamwidth (FNBW), and low dynamic range ratio (DRR). The results of proposed ALO‐SQP method are compared with those of 11 different algorithms: ALO, moth flame optimizer (MFO), SQP, symbiotic organisms search (SOS), biogeography based optimization (BBO), opposition‐based gravitational search algorithm (OGSA), cat swarm optimization (CSO), firefly algorithm (FA), evolutionary programming (EP), backtracking search optimization algorithm (BSA), and seeker optimization algorithm (SOA). The comparisons indicate that the CCAAs synthesis using the proposed method presents good MSLs, FNBWs, and DRRs.

Sidelobe level suppression for elliptical antenna arrays using modified SALP swarm algorithm

Abstract In this study, a modified version of salp swarm algorithm (MSSA) is used to synthesize elliptical antenna arrays (EAAs). The original salp swarm algorithm (SSA) is an optimization algorithm inspired by the behavior of salps in nature, which is used to solve engineering problems. The main purpose of the synthesis in this study is to obtain an EAA pattern with low maximum sidelobe levels (MSLs) for a fixed narrow first null beamwidth (FNBW). For different examples, the amplitude and angular position values of the antenna array elements are considered as optimization parameters. To show the effectiveness of the MSSA, eight examples of EAAs with 8, 12, and 20 elements are given. The results obtained with MSSA are compared with those of the antlion optimization, symbiotic organizations search, flower pollination algorithm, and accelerated particle swarm optimization from the literature. It is clear from the numerical results that MSSA outperforms the other algorithms in terms of the suppression of MSL.

Comparative and comprehensive study of linear antenna arrays’ synthesis

<span>In this paper, a comparative and comprehensive study of synthesizing linear antenna array (LAA) designs, is presented. Different desired objectives are considered in this paper; reducing the maximum sidelobe radiation pattern (i.e., pencil-beam pattern), controlling the first null beamwidth (FNBW), and imposing nulls at specific angles in some designs, which are accomplished by optimizing different array parameters (feed current amplitudes, feed current phase, and array elements positions). Three different optimization algorithms are proposed in order to achieve the wanted goals; grasshopper optimization algorithms (GOA), antlion optimization (ALO), and a new hybrid optimization algorithm based on GOA and ALO. The obtained results show the effectiveness and robustness of the proposed algorithms to achieve the wanted targets. In most experiments, the proposed algorithms outperform other well-known optimization methods, such as; Biogeography based optimization (BBO), particle swarm optimization (PSO), firefly algorithm (FA), cuckoo search (CS) algorithm, genetic algorithm (GA), Taguchi method, self-adaptive differential evolution (SADE), modified spider monkey optimization (MSMO), symbiotic organisms search (SOS), enhanced firefly algorithm (EFA), bat flower pollination (BFP) and tabu search (TS) algorithm.</span>

Unequally Spaced Antenna Array Synthesis Using Accelerating Gaussian Mutated Cat Swarm Optimization

Low peak sidelobe level (PSLL) and antenna arrays with high directivity are needed nowadays for reliable wireless communication systems. Controlling the PSLL is a major issue in designing effective antenna array systems. In this paper, a nature inspired technique, namely accelerating Gaussian mutated cat swarm optimization (AGMCSO) that attributes global search abilities, is proposed to control PSLL in the radiation pattern. In AGM-SCO, Gaussian mutation with an acceleration parameter is used in the position-updated equation, which allows the algorithm to search in a systematic way to prevent premature convergence and to enhance the speed of convergence. Experiments concerning several benchmark multimodal problems have been conducted and the obtained results illustrate that AGMCSO shows excellent performance concerning evolutionary speed and accuracy. To validate the overall efficacy of the algorithm, a sensitivity analysis was performed for different AGMCSO parameters. AGMCSO was researched on numerous linear, unequally spaced antenna arrays and the results show that in terms of generating low PSLL with a narrow first null beamwidth (FNBW), AGMCSO outperforms conventional algorithms.

An Improved Real-Coded Genetic Algorithm for Synthesizing a Massive Planar Array

The design of the Bi-State Antenna Massive Planar Array contributes to the mitigation of the energy consumption using the genetic algorithm under the constraints of minimizing the sidelobe level (SLL) and controlling the changing of the first null beamwidth (FNBW). Usually, Planar arrays are employed in communication applications based on battery usage such as portable radars. This paper optimizes a Uniform Rectangular Array (URA) with 1600 identical antenna elements using a Real-Coded Genetic Algorithm (RCGA). The optimization process is performed because the optimum set of the current excitation weight of radiating elements is found in the form of the ON-OFF state to conserve the consumed power. Hence, the highest performance of the Array Factor (AF) and the desired Beamwidth is selected. The main contribution presented in the paper is the ability to optimize a large number of array elements using the RCGA algorithm by dividing the array into a subset of arrays. The simulated results are performed to verify the effectiveness of the genetic thinned URA. The equivalent of 24.4% of the energy consumption is saved by selecting the antenna elements that could be scrambled with high effectiveness. In this paper, the results were obtained using MATLAB CAD Ver. 2018a as a platform.

Cylindrical phased array with adaptive nulling using eigen‐correlation technique

In this research work, eigen-correlation matrix based technique is developed for cylindrical antenna array to generate main beam and nulls simultaneously. The array complex weights (amplitude and phase) computed using the developed technique are used for single-beamforming, multi-beamforming, and beamforming with nulls steering simultaneously. The limitations of null steering range are investigated for different surface deformations of the cylindrical antenna array. The effects of surface deformations for different cylindrical radii on peak gain of main beam, half-power beamwidth, first-null beamwidth, and sidelobe level is also investigated. It is concluded that the developed eigen-correlation matrix based technique for cylindrical antenna array can be used for desired main beam generation and nulls steering simultaneously. The MATLAB, CST, and measurement validation of eight elements microstrip cylindrical phased array for single/multi-beams steering and adaptive nulling capability is demonstrated. This in turn makes the cylindrical phased array with adaptive nulling, a potential candidate suitable for use on fuselage portion of aircraft, airport surveillance radars, and mobile communication applications.

Analysis of Beam Forming Antenna using Soft-Computing Techniques

Antenna Beam forming is a technology or a technique that is finding increasing use in systems of cellular telecommunication, especially 5G, as well as many other wireless systems. Beam forming refers to the formation of a beam of energy from a set of phased arrays. With the use of phased arrays, it is possible to control the direction and shape of the beam from multiple antennas, based on the spacing between antennas and the phase of signal from each antenna element in the array. Beam forming focuses a wireless signal towards a specific receiving device, rather than having the signal spread in all directions from the broadcast antenna. By focusing signal in specific direction, the beam forming technique allows delivery of higher signal quality to the receiver, which would result in faster information transfer with fewer errors and without the need to boost the broadcast power. Beam forming technique is also used to reduce the interference of signals. Beam forming is majorly involved with computing resources which requires high time and power resources. Parameters that would be analyzed during this project are Half Power Beam width (HPBW), First Null Beam width (FNBW), Gain, Voltage Standing Wave Ratio, Front to Back Power Ratio, Side Lobe Levels.

An optimal time modulated compact circular antenna array design using a stochastic optimization technique

ABSTRACT This paper presents a time modulated far-field radiation pattern synthesis of a compact circular antenna array (CAA) by employing a stochastic optimization technique known as grey wolf optimization (GWO). The compactness of the antenna array is achieved by reducing the inter-element distances between the elements of the array which leads to the miniaturization of the antenna array size. On the other hand, an optimal far-field radiation characteristic is achieved by suppressing the side lobe level (SLL) as well as by narrowing the first null beamwidth (FNBW). A lower SLL value is necessary to avoid the interference with the system working in the same frequency, whereas, a narrow FNBW helps the antenna array to attain a high directivity. The performance of a time modulated antenna array (TMAA) depends on the rise on–off time, pulse shape as well as on the switching time duration of each element of the array which radiates at different harmonic frequencies. In this paper, the generation of radiation pattern at the fundamental/central frequency and its first two harmonic frequencies are considered for the design issue.

An optimal compact time-modulated circular antenna array synthesis using krill herd optimization

In this paper, an optimal far-field radiation pattern synthesis by using time modulation technique is carried out for a compact circular antenna array (CAA) design using a stochastic optimization method called krill herd (KH) optimization. A compact antenna array is achieved by reducing the inter-element spacing between the array elements, which leads to the miniaturization of the size of the array. On the other hand, an improved far-field radiation characteristic is achieved with a low side lobe level (SLL) and narrow first null beam width (FNBW). A low SLL is an essential requirement to reduce the interference with the other systems operating in the same frequency band. A narrow FNBW is necessary to obtain a high directivity. In time modulation technique, ‘time’ has the most significant role. It is considered the fourth-dimensional parameter, which plays the role of an additional degree of freedom to achieve an improved radiation pattern. The time-modulated antenna array (TMAA) radiates at various harmonic frequencies for the periodic switching time sequence. In this paper, the generation of the radiation pattern at the fundamental/central frequency only is considered. The KH algorithm is a flexible and robust search algorithm. It is applied here to find out the optimum sets of switching on-time duration for each array element and to determine the optimum inter-element separation between two array elements of the 20- and 36-element time-modulated circular antenna array (TMCAA). Particle swarm optimization (PSO) and differential evolution (DE) optimization techniques are also individually applied for the same design purpose to prove the superiority of the KH algorithm–based design. Finally, statistical analysis is performed to ensure the significance of the numerical results.

Evolution of conformal antenna design with the aid of probability improved crow search algorithm

PurposeThe issues of radiating sources in the existence of smooth convex matters by such objects are of huge significance in the modeling of antennas on structures. Conformal antenna arrays are necessary when an antenna has to match to certain platforms. A fundamental problem in the design is that the possible surfaces for a conformal antenna are infinite in number. Furthermore, if there is no symmetry, each element will see a different environment, and this complicates the mathematics. As a consequence, the element factor cannot be factored out from the array factor.Design/methodology/approachThis paper intends to enhance the design of the conformal antenna. Here, the main objective of this task is to maximize the antenna gain and directivity from the first-side lobe and other side-lobes in the two way radiation pattern. Thus the adopted model is designed as a multiobjective concern. In order to attain this multiobjective function, both the element spacing and the radius of each antenna element should be optimized based on the probability of the Crow Search Algorithm (CSA). Thus the proposed method is named Probability Improved CSA (PI-CSA). Here, the First Null Beam Width (FNBW) and Side-Lobe Level (SLL) are minimized. Moreover, the adopted scheme is compared with conventional algorithms, and the results are attained.FindingsFrom the analysis, the gain of the presented PI-CSA scheme in terms of best performance was 52.68% superior to ABC, 25.11% superior to PSO, 13.38% superior to FF and 3.21% superior to CS algorithms. Moreover, the mean performance of the adopted model was 62.94% better than ABC, 13.06% better than PSO, 24.34% better than FF and 10.05% better than CS algorithms. By maximizing the gain and directivity, FNBW and SLL were decreased. Thus, the optimal design of the conformal antenna has been attained by the proposed PI-CSA algorithm in an effective way.Originality/valueThis paper presents a technique for enhancing the design of the conformal antenna using the PI-CSA algorithm. This is the first work that utilizes PI-CSA-based optimization for improving the design of the conformal antenna.

Side lobe level reduction of thinned concentric elliptical array antenna in vertical and horizontal plane for a desired peak directivity

AbstractThis study, describes the design problem of a thinned multiple concentric elliptical arrays of uniformly excited isotropic antennas using meta‐heuristic optimization algorithms; Teaching Learning Based Optimization (TLBO), Crow Search Algorithm (CSA) and Moth Flame Optimization (MFO) algorithm. Two simulations are performed here. In simulation 1, the synthesis of the thinned array structure is presented in the vertical plane at a scanning angle 30° and in simulation 2, the synthesis is performed in the horizontal plane. In both cases, our objective is to minimize side lobe level (SLL) to the extent possible and at the same time maximize the peak directivity to a level higher than the desired value. Here, all the optimization algorithms are applied to obtain the optimum number of switched on and off elements in every concentric ellipse that will meet the above objective. A comparative analysis of all three algorithms is performed using peak directivity, SLL and first null beam width (FNBW) as well as statistical parameters such as mean, SD, best cost function value and run time. To assess the enhanced outcome of the proposed optimization design comparison is also made with the results of a fully populated concentric elliptical array antenna (CEAA) for both the cases separately. This paper shows a measure of effectiveness and potential of all the algorithms mentioned above, for designing a thinned concentric elliptical array.

An optimal far‐field radiation pattern synthesis of time‐modulated linear and concentric circular antenna array

AbstractIn this paper, an optimal far‐field radiation pattern synthesis by using time modulation technique is carried out for linear antenna array (LAA), and concentric circular antenna array (CCAA) designs using a stochastic optimization method called grey wolf optimization (GWO). An improved far‐field radiation characteristic mainly depends on the synthesis of low side lobe level (SLL) and narrow first null beam width (FNBW). A low SLL is a requirement to reduce the interference by the other systems operating in the same frequency band. A narrow FNBW is necessary to obtain a high directivity. In time modulation technique, “time” has a most significant role. It is considered as the fourth‐dimensional parameter as it plays the role of an additional degree of freedom to achieve an improved radiation pattern. The time‐modulated antenna array (TMAA) radiates at various harmonic frequencies for the periodic switching time sequence. In this paper, the generation of radiation pattern only at the fundamental/central frequency and at its first two harmonic frequencies are considered. The GWO algorithm is a flexible and robust search algorithm and is applied here to find out the optimum sets of switching on‐time duration for each array element and to determine the optimum inter‐element separation between two array elements of the 16‐element time‐modulated linear antenna array (TMLAA) and the nine‐ring time‐modulated concentric circular antenna array (TMCCAA). The GWO algorithm‐based results show a substantial improvement in far‐field radiation pattern synthesis compared with the uniform radiation pattern and those of the methods reported in state‐of‐the‐art literature.

A Novel Elliptical-Cylindrical Antenna Array for Radar Applications

With the advancement of radar technology, detecting objects, determining the structure of the target, and estimating the direction and the speed is prominently increasing. There is no doubt that small cross section targets are hardly identified and determined. This problem demands the need for antenna pattern synthesizing with a high gain and highly reduced sidelobe level (SLL). In this paper, an optimization technique called self-adaptive differential evolution (SaDE) that can be able to learn and behave intelligently is integrated to determine an optimal set of excitation weights in the design of elliptical–cylindrical antenna array (ECAA). In this work, the SaDE-optimized hyper beam is proposed to achieve qualified radar performances. Nonuniform excitation amplitudes of the individual array elements of ECAA are performed to obtain reduced SLL, high directivity, and flexible radiation pattern which are crucial in radar applications. With increased antenna gain, small cross section objects can be accurately identified and determined even in volatile environment where there are different natures of interferences. Besides, the proposed work enables steering electronically and it allows scanning very rapidly across a wide range of elevation and azimuth planes. To evaluate the improved performance of the proposed optimization scheme, comparison is done with genetic algorithm (GA), particle swarm optimization (PSO), biogeography-based optimization (BBO), and invasive weed optimization (IWO) against different parameters. In general, the proposed work of pattern synthesis has resulted in much better reduction in SLL and first null beamwidth (FNBW) than both the uniformly excited and thinned ECAA. The results of this study clearly revealed that the SLL is highly reduced at a very directive beamwidth. The proposed antenna array offers high system availability over wide range of radar applications.

Synthesis of Highly Directive Endfire Arrays Using Modified Chebyshev Polynomials

In this paper an additional parameter in the Chebyshev polynomial is introduced so as to design an endfire array by controlling two factors of the radiation characteristics- namely the Half Power Beam Width(HPBW) and the side lobe level(SLL) simultaneously. It has been shown that for a given SLL improved HPBW and First Null Beam Width (FNBW) can be achieved. Individual elements in the array are assumed to be isotropic. Simulations were carried out to find bounds on the choice of HPBW and SLL. Simulation results also shows that the directivity can be improved over the Dolph-Chebyshev array. Improvement in the roll off characteristics are also shown. Implementation of the array using the coefficients obtained by this synthesized procedure can result in a highly directive array.