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.

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.

A Crossover Improved Genetic Algorithm and Its Application in Non-Uniform Linear Antenna Arrays

2017 ◽  
Vol 16 (04) ◽  
pp. 1750027 ◽  
Author(s):  
Bhargav Appasani ◽  
Rahul Pelluri ◽  
Vijay Kumar Verma ◽  
Nisha Gupta
Keyword(s):  
Genetic Algorithm ◽  
Antenna Arrays ◽  
Optimization Technique ◽  
Beam Width ◽  
Side Lobe ◽  
Optimization Techniques ◽  
Linear Antenna ◽  
Improved Genetic Algorithm ◽  
Element Array ◽  
Linear Antenna Arrays

Genetic Algorithm (GA) is a widely used optimization technique with multitudinous applications. Improving the performance of the GA would further augment its functionality. This paper presents a Crossover Improved GA (CIGA) that emulates the motion of fireflies employed in the Firefly Algorithm (FA). By employing this mimicked crossover operation, the overall performance of the GA is greatly enhanced. The CIGA is tested on 14 benchmark functions conjointly with the other existing optimization techniques to establish its superiority. Finally, the CIGA is applied to the practical optimization problem of synthesizing non-uniform linear antenna arrays with low side lobe levels (SLL) and low beam width, both requirements being incompatible. However, the proposed CIGA applied for the synthesis of a 12 element array yields an SLL of [Formula: see text]29.2[Formula: see text]dB and a reduced beam width of 19.1[Formula: see text].

Electromagnetic Characteristics of Yagi-Uda Antenna at HF/VHF/UHF

2018 ◽  
Vol 3 (2) ◽  
pp. 7-11
Author(s):  
Raji A. Abimbola
Keyword(s):  
Electric Field ◽  
Method Of Moments ◽  
Current Distribution ◽  
High Frequency ◽  
Very High Frequency ◽  
Radiation Characteristics ◽  
Radiation Beam ◽  
Field Patterns ◽  
Electromagnetic Characteristics ◽  
Very High

In this paper, the radiation characteristics of Yagi-Uda antenna operating at High Frequency (HF), Very High Frequency (VHF) and Ultra High Frequency (UHF) are examined. Upon employing method of moments, the current distribution on the antenna emerges from the solution of matrix equation. It is found that the angular distribution of electric field intensity generated in free space by the antenna, obtained by evaluating the integral of associated current distribution, is characterized by patterns with significant portion of radiation beam in the main lobe in the direction of Yagi axis. This is accompanied by relatively small undesirable radiation in the minor lobe, and which persist over those communication frequencies. It is observed also that the current distribution that generates the radiated electric field patterns is relatively consistent over the same range of frequency.

scholarly journals Constrained synthesis of the Linear Antenna Array using Social Group Optimization

2018 ◽  
Vol 7 (2.17) ◽  
pp. 105 ◽  
Author(s):  
Abdul Rahiman Sheik ◽  
Dr Kalva Sri Rama Krishna
Keyword(s):  
Radiation Pattern ◽  
Social Group ◽  
Beam Width ◽  
Linear Antenna ◽  
Sidelobe Level ◽  
Array Design ◽  
Linear Arrays ◽  
Simulation Based ◽  
Social Group Optimization ◽  
Novel Algorithm

In this paper, novel algorithm known as social group optimization is use for array synthesis problem. The algorithm is implemented to the electromagnetic problem solving and its performance is evaluated. The array design is carried out with the objective of sidelobe level (SLL) suppression with uniform beam width (BW) constraint. The amplitude only technique is used to determine the coefficients of current excitation which produce the desired radiation pattern with the objectives and constraints. The analysis is carried out in terms of radiation pattern for different length of linear arrays. The simulation based experimentation is carried out in Matlab.  

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 Acoustic Beam Forming Using Ultrasonic Transducers

2012 ◽  
Vol 4 ◽  
pp. 238-242
Author(s):  
Wen Kung Tseng
Keyword(s):  
Optimization Technique ◽  
Audio Signal ◽  
Beam Width ◽  
Side Lobe ◽  
Ultrasonic Transducers ◽  
Main Lobe ◽  
Beam Forming ◽  
Acoustic Beam ◽  
Sound Beam ◽  
Audible Sound

This paper evaluates the performance of acoustic beam forming using ultrasonic transducers. A directional audible sound can be generated by amplitude-modulating the ultrasound carrier with an audio signal, then transmitting it from an array of ultrasonic transducers. A novel method has been proposed in this paper to control the beam width of the main lobe and the level of the side lobe for the beam pattern by using an optimization technique. Furthermore, the weighting distribution of uniform linear array composed of eight transducers and the effect of different weightings on the spreading angle of the sound beam have been investigated through simulations in this study. The results show that the optimization method proposed in the paper can effectively control the beam width of the main lobe and the level of the side lobe for the audible sound.

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).

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