scholarly journals Optimal Pattern Synthesis of Linear Array and Broadband Design of Whip Antenna Using Grasshopper Optimization Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Hengfeng Wang ◽  
Chao Liu ◽  
Huaning Wu ◽  
Bin Li ◽  
Xu Xie

Antenna arrays with high directivity, low side-lobe level, and null control in desired direction and whip antenna with wider bandwidth both need to be optimized to meet different needs of communication systems. A new natural heuristic algorithm simulating social behavior of grasshoppers, grasshopper optimization algorithm (GOA), is applied to electromagnetic field as a new effective technology to solve the antenna optimization problem for the first time. Its algorithm is simple and has no gradient mechanism, can effectively avoid falling into local optimum, and is suitable for single-objective and multiobjective optimization problems. GOA is used to optimize the side lobe suppression, null depth, and notch control of arbitrary linear array and then used to optimize the loading and matching network of 10-meter HF broadband whip antenna compared with other algorithms. The results show that GOA has more advantages in side-lobe suppression, null depth, and notch control of linear array than other algorithms and has better broadband optimization performance for HF whip antenna. The pattern synthesis and antenna broadband optimization based on GOA provide a new and effective method for antenna performance optimization.

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Lei Liang ◽  
Jie Sun ◽  
Hailin Li ◽  
Jialing Liu ◽  
Yachao Jiang ◽  
...  

An efficient pattern synthesis approach is proposed for the synthesis of a time-modulated sparse linear array (TMSLA) in this paper. Due to the introduction of time modulation, the low/ultralow side lobe level can be obtained with a low amplitude dynamic range ratio. Besides, it helps reduce the difficulty of antenna feeding system effectively. Based on particle swarm optimization (PSO) and convex (CVX) optimization, this paper proposes a hybrid optimization method to suppress the grating lobes of the sparse arrays, peak side lobe level (PSLL), and peak sideband level (PSBL). Firstly, the paper utilizes the CVX optimization as a local optimization algorithm to optimize the elements’ switch-on duration time, which reduces the side lobe of the array. Secondly, with the PSBL as the objective function, the paper adopts the PSO as a global optimization algorithm to optimize the elements’ positions and switch-on time instant, which helps reduce the loss of sideband power caused by time modulation. With respect to the time modulation model, variable aperture sizes (VAS) and more flexible pulse-shifting (PS) schemes are used in this paper. Owing to the introduction of time modulation and CVX optimization, the proposed method is much more feasible and efficient than conventional approaches. Furthermore, it has better array pattern synthesis performance. Numerical examples of the TMSLA and comparisons with the reference are presented to demonstrate the effectiveness of the proposed method.


Author(s):  
Gebrehiwet Gebrekrstos Lema

<p>For high performance communication systems, Side Lobe Level (SLL) reduction and improved directivity are the goal of antenna designers. In the recent years, many optimization techniques of antenna design are occupying demanding place over the analytical techniques. Though they have contributed attractive solutions, it is often obvious to select one that meets the particular design need at hand. In this paper, an optimization technique called Self-adaptive Differential Evolution (SaDE) that can be able to learn and behave intelligently along with hyper beam forming is integrated to determine an optimal set of excitation weights in the design of EcAA. Non-uniform excitation weights of the individual array elements of EcAA are performed to obtain reduced SLL, high directivity and flexible radiation pattern. To evaluate the improved performance of the proposed SaDE optimized hyper beam, comparison are done with uniformly excited, SaDE without hyper beam and Genetic Algorithm (GA). In general, the proposed work of pattern synthesis has resulted in much better reduction of SLL and FNBW than both the uniformly excited and thinned EcAA. The results of this study clearly reveal that the SLL highly reduced at a very directive beamwidth.</p>


Author(s):  
Luyen Van Tong ◽  
Vu Bang Giang Truong

In this study, an adaptive beamformer for pattern nulling of Uniformly Spaced Linear Array (ULA) antennas, which utilized BAT algorithm (BA) to suppress interferences, has been proposed. This pattern nulling has been obtained by controlling the complex weight (both the phase and the amplitude) of each array element. So as to verify the proposal, a number of scenarios of ULA pattern imposed the pre-set nulls have been carried out and compared with those of accelerated particle swarm optimization (APSO). The proposed beamformer has demonstrated the capability to place with precise single, multiple, and broad nulls at arbitrary interference directions, suppress side lobes, and maintain a predefined beamwidth. Moreover, the beamformer shows faster convergence and higher efficiency regarding null steering and side lobe suppression in pattern synthesis, as compared with an APSO based beamformer.


Author(s):  
Ali Durmus ◽  
Rifat Kurban

Abstract In this paper, equilibrium optimization algorithm (EOA), which is a novel optimization algorithm, is applied to synthesize symmetrical linear antenna array and non-uniform circular antenna array (CAA). The main purpose of antenna array synthesis is to achieve a radiation pattern with low maximum side lobe level (MSL) and narrow half-power beam width (HPBW) in far-field. The low MSL here is an important parameter to reduce interference from other communication systems operating in the same frequency band. A narrow HPBW is needed to achieve high directionality in antenna radiation patterns. Entering the literature as a novel optimization technique, EOA optimally determined the amplitude and position values of the array elements to obtain a radiation pattern with a low MSL and narrow HPBW. The EOA is inspired by models of the control volume mass balance used to predict equilibrium as well as dynamic states. To demonstrate the flexibility and performance of the proposed algorithm, 10-element, 16-element and 24-element linear arrays and eight-element, 10-element and 12-element CAAs are synthesized. The MSL and HPBW values of radiation pattern obtained with the EOA are very successful compared to the results of other optimization methods in the literature.


Antenna arrays are prominently used in satellites, radars mobile and wireless communication systems. Design of an antenna array with minimum side projections is the crucial component for noise free communications. There are various nature inspired optimization method have been suggested to optimize the peak side projections. To overcome low solution accuracy and low convergence rate, we are using newly developed Cauchy mutated invasive and optimization (CMIWO) to minimize the peak side projection levels in the radiation pattern. CMIWO is adapted to reduce the amplitude of the each antenna element. We have used 24, 32, and 64 element linear array of antenna for the synthesis. Based on the results the CMIWO produces suggestive reduction in peak side projections when contrasted with other array of antennas


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Reza Kazemi ◽  
Mohsen Fallah ◽  
Bijan Abbasi ◽  
Seyyed Hossein MohseniArmaki

Purpose The purpose of this study is to achieve the low-cost, light-weight and compact antenna array with wide bandwidth and low side lobe levels for synthetic aperture radar (SAR) applications in Ku frequency band. Design/methodology/approach A compact design of a rectangular microstrip patch antenna array using multilayered dielectric structure is presented in Ku-band for advanced broadband SAR systems. In this design, stepped pins are used to connect the microstrip feed lines to the radiating patches. Findings The simulation and fabrication results of the multilayered antenna and a 1×16-element linear array of the antenna with Taylor amplitude distribution in the feeding network are presented. The antenna element has a 10-dB impedance bandwidth of more than 26%, and the linear array shows reduction in bandwidth percentage (about 15.4%). Thanks to Taylor amplitude tapering, the side lobe level (SLL) of the array is lower than −24 dB. The maximum measured gains of the antenna element and the linear array are 7 and 19.2 dBi at the center frequency, respectively. Originality/value In the communication systems, a high gain narrow beamwidth radiation pattern achieved by an array of multiple antenna elements with optimized spacing is a solution to overcome the path loss, atmospheric loss, polarization loss, etc. Also, wideband characteristics and compact size are desirable in satellite and SAR systems. This paper provides the combination of these features by microstrip structures.


2018 ◽  
Vol 7 (4.5) ◽  
pp. 273
Author(s):  
Challaram Grandhi ◽  
N. Grandhi1*, N.Venkateswara rao

In many communication systems like Radar and point to point micro links there is a need of both narrow and wide beams. In target applications Antennas with narrow beam width is required on the other hand, for spy application antennas with wider beam width are required. Generally, for linear array antennas the beams width will be narrowed by increase in the number of elements in the array. To obtain narrow beams without a significant increase in the number of radiation elements in the array, the optimization algorithms are used. By the use of optimization algorithms the wider beams can also be employed in reverse procedure of choosing the highest output for a given set of random inputs. These wide ranges of beam width are obtained without any increase in the side lobe levels that is, by maintaining the side lobe level below -20db. Random stochastic methods like Particle swarm optimization (PSO), Genetic algorithm (GA), Biogeography-based optimization (BBO) and Differential Evolution Algorithm (DE) are used and the results are compared.  


In many areas of wireless communications, there is a need for high directive radiating beams. To generate such a high directive beams, a linear array of antennas is preferred to that of using a single antenna. Generally a narrow beam width tends to have high directivity but specific to the applications there is also a need for wider beam widths. In case of a radar application it requires a narrow beam width when it is operating in target mode and on the other hand it requires wider beam width when it works under search mode. These optimal beam width variations can be obtained by using Optimization techniques. In this paper Biogeography based Optimization algorithm is used to generate narrow and wide beam widths for a Linear array antenna. While we try to optimize the beam widths of a linear array it will lead to an increase in the side lobe level which make it unavailable for practical applications. As a sensible antenna should always posses a very low side lobe levels a tradeoff should be made for both side lobe level and beam width. This tradeoff which has an optimal side lobe level along with directivity can be achieved by proposed fitness function optimization. The results obtained by using Genetic algorithm and Biogeography based optimization algorithm are compared


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