scholarly journals Multiobjective Synthesis of Steerable UWB Circular Antenna Array considering Energy Patterns

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Leopoldo A. Garza ◽  
Marco A. Panduro ◽  
David H. Covarrubias ◽  
Alberto Reyna
Keyword(s):  
Antenna Arrays ◽  
Side Lobe ◽  
Main Beam ◽  
Side Lobe Level ◽  
Optimized Design ◽  
Circular Array ◽  
Circular Arrays ◽  
True Time ◽  
Uwb Applications ◽  
Circular Antenna Array

True-time delay antenna arrays have gained a prominent attention in ultrawideband (UWB) applications such as directional communications and radar. This paper presents the design of steerable UWB circular array by using a multiobjective time-domain synthesis of energy pattern for circular antenna arrays. By this way we avoid individual beamforming for each frequency in UWB spectrum if the problem was addressed from the frequency domain. In order to obtain an energy pattern with low side lobe level and a desired main beam, the synthesis presented is performed by optimizing the true-time delays and amplitude coefficients for the antenna elements in a circular geometry. The method of Differential Evolution for Multiobjective Optimization (DEMO) is used as the optimization algorithm in this work. This design of steerable UWB circular arrays considers the optimization of the true-time exciting delays and the amplitude coefficients across the antenna elements to operate with optimal performance in the whole azimuth plane (360°). A comparative analysis of the performance of the optimized design with the case of conventional progressive delay excitations is achieved. The provided results show a good performance for energy patterns and for their respective power patterns in the UWB spectrum.

scholarly journals Design of Non-Uniformly Spaced Circular Arrays of Parasitic Dipoles for Lower Side Lobe Level with Maximum Directivity

2018 ◽  
Vol 7 (1) ◽  
pp. 51-56 ◽  
Author(s):  
H. Patidar ◽  
G. K. Mahanti
Keyword(s):  
Mutual Coupling ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Circular Array ◽  
Method Of Moment ◽  
Lower Side ◽  
New Approach ◽  
Circular Arrays ◽  
Maximum Directivity ◽  
Active Dipole

This paper presents a new approach for circular array of parasitic dipoles composed by one active dipole for reduction of side lobe level with maximum directivity including mutual coupling. The desired goal is obtained by changing the spacing between the parasitic elements and length of the parasitic elements while the position and length of driven element is fixed. In addition to it, reflection coefficient (RC) of the driven element is kept closer to the specified value. Matlab based method of moment code is used to evaluate the performance of circular antenna designs generated by QPSO algorithm. Two examples are presented to show the effectiveness of this proposed approach.  

scholarly journals Investigation on SIW Slot Antenna Array with Beam Scanning Ability

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Yanfei Li ◽  
Yang Li
Keyword(s):  
Genetic Algorithm ◽  
Antenna Array ◽  
Antenna Arrays ◽  
Beam Width ◽  
Side Lobe ◽  
Slot Antenna ◽  
Main Beam ◽  
Side Lobe Level ◽  
Substrate Integrated Waveguide ◽  
Beam Scanning

A sparse substrate integrated waveguide (SIW) slot antenna array and its application on phase scanning are studied in this paper. The genetic algorithm is used to optimize the best arrangement for 8-element and 7-element sparse arrays over an aperture of 4.5λ0. Antenna arrays with feeding networks, for steering the main beam pointing to 0° and −15°, are demonstrated with the SIW technology. The comparison between the sparse array and the conventional uniformly spaced array with the same aperture are presented, which suggest that the same beam width can be obtained with the gain decreased by 0.5 or 1 dBi and the number of element reduced by 2 or 3, respectively. The sparse antenna array with beam scanning ability presented in this paper shows that, while the beam scanning in the range of ±15°, the gain fluctuation is less than 0.3 dBi and the side lobe level is lower than −10 dB.

scholarly journals Thinning of Concentric Circular Antenna Arrays Using Improved Binary Invasive Weed Optimization Algorithm

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Huaning Wu ◽  
Chao Liu ◽  
Xu Xie
Keyword(s):  
Antenna Arrays ◽  
Optimization Algorithm ◽  
Optimization Technique ◽  
Side Lobe Level ◽  
Circular Array ◽  
Invasive Weed Optimization ◽  
Pattern Synthesis ◽  
Invasive Weed ◽  
Circular Arrays ◽  
Concentric Circular Arrays

This study presents a novel optimization algorithm based on invasive weed optimization (IWO) for reduction of the maximum side lobe level (SLL) with specific half power beam width (HPBW) of thinned large multiple concentric circular arrays of uniformly excited isotropic elements. IWO is a powerful optimization technique for many continuous problems. But, for discrete problems, it does not work well. In this paper, the authors propose an improved binary IWO (IBIWO) for pattern synthesis of thinned circular array. The thinning percentage of the array is kept equal to or more than 50% and the HPBW is attempted to be equal to or less than that of a fully populated, uniformly excited, and half wavelength spaced concentric circular array of the same number of elements and rings. Simulation results are compared with previous published results of DE, MPSO, and BBO to verify the effectiveness of the proposed method for concentric circular arrays.

scholarly journals A Hybrid GA/GE Beamforming Technique for Side Lobe Cancellation of Linear Antenna Arrays

2021 ◽  
Vol 10 (2) ◽  
pp. 67-77
Author(s):  
S. I. Abdelrahman ◽  
A. H. Hussein ◽  
A. E. A. Shaalan
Keyword(s):  
Antenna Arrays ◽  
Optimization Technique ◽  
Side Lobe ◽  
Main Beam ◽  
Side Lobe Level ◽  
Linear Antenna ◽  
Gauss Elimination ◽  
Half Power ◽  
Beamforming Technique ◽  
Linear Antenna Arrays

Side lobe level reduction is one of the most critical research topics in antenna arrays beamforming as it mitigates the interfering and jamming signals. In this paper, a hybrid combination between the Genetic algorithm (GA) optimization technique and the gauss elimination (GE) equation solving technique is utilized for the introduction of the proposed GA/GE beamforming technique for linear antenna arrays. The proposed technique estimates the optimum excitation coefficients and the non-uniform inter-elements spacing for a specific side lobe (SL) cancellation without disturbing the half power beamwidth (HPBW) of the main beam. Different size Chebychev linear antenna arrays are taken as simulation targets. The simulation results revealed the effectiveness of the proposed technique

Circular aerial arrays for radio astronomy

1961 ◽  
Vol 262 (1308) ◽  
pp. 84-99 ◽  
Keyword(s):  
Radio Astronomy ◽  
Side Lobe ◽  
Correction Function ◽  
Side Lobe Level ◽  
Circular Aperture ◽  
Circular Array ◽  
Polar Diagram ◽  
Beam Shape ◽  
Correction Process ◽  
Dimensional Distribution

A new type of aerial array suitable for high-resolution observations in radio astronomy is explored theoretically. The array consists of a large number of aerial elements equally Spaced round a circle and electrically connected in phase. The power polar diagram is calculated for the cases when the circle is effectively continuous, and when the separation between adjacent elements is appreciable. In both cases the side-lobe level is rather high for most radio astronomical purposes, for which a process of aerial correction is required. The function of the correction process is to readjust the relative weights of the different spatial Fourier components to provide a suitable beam shape. A general method of aerial correction is developed in which the two dimensional distribution of brightness directly recorded by scanning is cross-correlated with a circularly symmetrical correction function , a process which is desirably performed in the instrument itself. The correction process allows one to convert the polar diagram of a ring-shaped array into (for example) the diagram of a uniform circular aperture of the same radius. The principal theoretical characteristics of the circular array are briefly compared with those of the Mills cross. It is found that while the process of aerial correction or ‘tapering’ is technically more straightforward in the cross, the circular array has the following advantages: (1) the length of transmission line (and hence attenuation) between each element and receiver is halved; (2) the number of elements required to gain the same information is reduced, approximately in the ratio 4: π ; (3) the beam possesses circular or elliptical symmetry; and (4) the system offers the possibility of direct phase and amplitude calibration with the aid of a transmitter situated on a central tower.

scholarly journals Null Steering in Failed Antenna Arrays

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Om Prakash Acharya ◽  
Amalendu Patnaik ◽  
Sachendra N. Sinha
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Correction Procedure ◽  
Swarm Optimization ◽  
Array Pattern ◽  
Null Steering ◽  
Simulation Results ◽  
Pattern Simulation

Antenna array pattern nulling is desirable in order to suppress the interfering signals. But in large antenna arrays, there is always a possibility of failure of some elements, which may degrade the radiation pattern with an increase in side lobe level (SLL) and removal of the nulls from desired position. In this paper a correction procedure is introduced based on Particle Swarm Optimization (PSO) which maintains the nulling performance of the failed antenna array. Considering the faulty elements as nonradiating elements, PSO reoptimizes the weights of the remaining radiating elements to reshape the pattern. Simulation results for a Chebyshev array with imposed single, multiple, and broad nulls with failed antenna array are presented.

scholarly journals The optimal synthesis of scanned linear antenna arrays

2020 ◽  
Vol 10 (2) ◽  
pp. 1477
Author(s):  
Anas A. Amaireh ◽  
Asem S. Al-Zoubi ◽  
Nihad I. Dib
Keyword(s):  
Antenna Arrays ◽  
Firefly Algorithm ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Linear Antenna ◽  
Symbiotic Organisms Search ◽  
Optimization Parameters ◽  
Antlion Optimization ◽  
Symbiotic Organisms ◽  
Linear Antenna Arrays

In this paper, symmetric scanned linear antenna arrays are synthesized, in order to minimize the side lobe level of the radiation pattern. The feeding current amplitudes are considered as the optimization parameters. Newly proposed optimization algorithms are presented to achieve our target; Antlion Optimization (ALO) and a new hybrid algorithm. Three different examples are illustrated in this paper; 20, 26 and 30 elements scanned linear antenna array. The obtained results prove the effectiveness and the ability of the proposed algorithms to outperform and compete other algorithms like Symbiotic Organisms Search (SOS) and Firefly Algorithm (FA).

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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