Figure 2 - uploaded by Shahideh Kiehbadroudinezhad
Content may be subject to copyright.
Source publication
An array of antennas is usually used in long distance communication. The observation of celestial objects necessitates a large array of antennas, such as the Giant Metrewave Radio Telescope (GMRT). Optimizing this kind of array is very important when observing a high performance system. The genetic algorithm (GA) is an optimization solution for the...
Context in source publication
Citations
... The Three values characterize venom, ∅ longitude, and radial distance, R (equivalent to the Earth's radius of approximately 6378100 meters), Utilized to ascertain the Coordinates in a sphere of a given point. Applying the following formula [21]: ...
... Genetic algorithms have been employed for optimizing various design aspects of array antennas of various geometries e.g., uniformly spaced linear arrays, non-uniformly spaced linear arrays, planar arrays and for various applications e.g., radio astronomy [8], satellite communications, mmWave MIMO systems etc. In 2007, Villegas et al. proposed using a GA to optimize the shaped beam coverage areas of planar 2D phased arrays, using a planar rectangular array of 10 × 10 elements as a case study [9]. ...
... The Y-like array shapes include cross-type, T-type, and Y-type shapes [10], and the round-like shapes include circular-type [11], Reuleaux triangle-type [12], and spirals-type [13] shapes, as shown in Fig. 3. In addition, there are some algorithms that study random arrangements, such as sieving methods [14], genetic algorithms [15], and particle swarm algorithms [16], which have also achieved good results. In our current design, the size of the single sub-aperture of the lenslet array is smaller than that of the existing synthetic aperture array, but the number of lenslets is larger. ...
Compared with the traditional imaging systems, segmented planar imaging technology has the advantages of low mess, small size, and low power in the same resolution situation. To obtain relatively complete frequency domain coverage, the lenslet array requires a large number of lenslets, and the photonic integrated circuit board requires a large number of optical devices, which limits the application and development of the segmented planar imaging technology. In this paper, we introduce a novel, to the best of our knowledge, design of the photonic integrated circuit to ensure that each lenslet in the lenslet array can form a baseline with any other lenslets. This breaks the barrier between segmented planar imaging technology and the traditional synthetic aperture, giving segmented planar imaging technology a sufficient number of frequency domain samples and a concise photonic integrated circuit structure.
... For a 10 element linear array, it can be noted from literature [3] that GWO produces a peak SLL of −23.42 dB which is 10.19 dB lower to that of conventional array. The three fundamental steps that define the genetic algorithm are evaluation, selection and recombination [4]- [6]. Genetic Algorithm offers several advantages which makes it more commanding than other optimization techniques [6]. ...
This paper aims to synthesize a uniform rectangular array (URA) which spans beamwidth of -30∘ to 30∘ in the azimuthal direction with the interference direction as 40∘ in the azimuth plane. In this paper, a Modified Genetic Algorithm is proposed which works to produce a beam pattern with a narrow beamwidth, high directivity and maximized side lobe level (SLL) suppression. The simulation results for the proposed algorithm demonstrates that the synthesized beam pattern for a 16x16 URA at a frequency of 1 GHz converges to the desired optimum solution producing a maximum SLL suppression of -30dB.
... In antenna design optimization, algorithms inspired by natural processes have been applied, and they are genetic algorithms (GAs) [14][15][16][17], particle swarm optimization (PSO) [18,19], and their variants [20,21]. Genetic algorithm (GA)-based optimization algorithms have been utilized for antenna array positioning and have been successful in finding optimized antenna schemes [22]. ...
In this paper, optimization of a miniaturized multiple-inputs multiple-outputs (MIMO) antenna was performed. This antenna was composed of a T-shape radiating element with stub and reduced ground plane and a compact size of 25 mm × 25 mm × 1.6 mm. The behavior of antenna was evaluated in terms of return loss (S-parameter < −10 dB), electromagnetic interference (EMI), and operation frequency. The antenna design is applicable to many applications. A 2K factorial design combined with a genetic algorithm (GA) optimization technique were used to identify the key design parameters responsible for affecting the performance quality of the antenna. Optimization of the antenna design for EMI reduction was utilized, and the optimal design showed enhanced bandwidth of the antenna and reduced power consumption.
... Fungsi tujuan merepresentasikan tujuan yang ingin dioptimalkan. Karena jumlah fungsi tujuannya lebih dari satu, maka solusi optimum dari multi-criteria optimization problem juga lebih dari satu, yang kesemuanya masuk ke dalam sebuah set yang disebut Pareto frontier [9], [10]. Hal ini sejalan dengan prinsip dimana tidak ada satu pun solusi yang mampu memberikan hasil yang lebih optimal dari salah satu fungsi tujuan yang ada tanpa mengorbankan fungsi tujuan lainnya. ...
Wilayah Pengelolaan Perikanan Republik Indonesia (WPP-RI) terdiri dari 11 wilayah. Salah satunya adalah WPP-712 yang merupakan wilayah Laut Jawa. WPP-712 mencakup pulau Jawa yang terdiri dari 8 Provinsi, yaitu Provinsi Lampung, Banten, DKI Jakarta, Jawa Barat, Jawa Tengah, Jawa Timur, Kalimantan Tengah dan Kalimantan Selatan. Dengan Luas Wilayah 160.309 square milles. Permasalahan di WPP-712 adalah memiliki tingkat kerawanan yang tinggi dan sering terjadinya gejala tangkap lebih (overfishing). Salah satu faktor yang mempengaruhi adalah sedikitnya kapal pengawas perikanan milik Kementrian Kelautan yang ditugaskan di WPP-712. Tujuan dari penelitian ini adalah menentukan jumlah kapal pengawas perikanan yang di tugaskan di WPP-712. Untuk menyelesaikan permasalahan tersebut metode yang digunakan adalah metode Genetic Algorithms (GA). GA adalah sebuah metode optimasi yang paling banyak digunakan untuk permassalahan multi-obyektif. Hasil dari implementasi GA merekomendasikan jumlah kapal yang beroperasi di WPP-712 adalah 5 kapal dengan tipe A-B-C-B-D dengan capaian coverage area 167.334 Mil 2 dan biaya operasional Rp. 1.319.621.100. Temuan dalam penelitian ini bisa digunakan sebagai pertimbangan oleh Pemerintah untuk menentukan kebijakan peningkatan keamanan laut Indonesia.
... It involves the efforts of more than 10 countries. Although it will observe the blue sky and produce images with very high sensitivity, its image quality is still limited and affected by the sidelobe levels (SLLs ;Hall 2007;El-makadema et al. 2014;Shahideh et al. 2014;Gie et al. 2016). On the other hand, it is shown that the value of unsampled points in the u-v coverage can be a standardized indication of the SLLs of the beam generated by an array system. ...
Aperture synthesis arrays are commonly used in radio astronomy to take images of radio point sources, with the planned Square Kilometre Array (SKA) being the most common example. One approach to enhancing the quality of the images is to optimize an antenna array configuration in a possible SKA implementation. An ideal arrangement must ensure optimal configurations to capture a clear image by either decreasing the sidelobe level (SLL) in the l–m domain or increasing the sampled data in the spatial-frequency domain. In this paper a novel configuration is considered to optimize the array by considering all possible observation situations through the positions of the antenna array elements via a mathematical model that we call geometrical method (GM). To demonstrate its efficiency, the technique is applied to developing an optimal configuration for the elements of the Giant Metrewave Radio Telescope (GMRT). The effect of these changes, particularly in the forms of circular and spiral arrangements, is discussed. It is found that a spiral configuration results in fewer overlapping samples than the number of antennas placed along three arms of the GMRT with fewer than 11% and 27% overlapping samples in the snapshot and 6 hr tracking observations, respectively. Finally, the spiral configuration reduces the first SLL from −13.01 dB, using the arms of the current GMRT configuration, to −15.64 dB.
... There are several notable works doneonoptimization of antenna arrays, among them: Kogan 2000;Boone 2001Boone , 2002Cohanim et al. 2004;Su et al. 2004;Karastergiou et al. 2006;Jin & Rahmat-Samii 2008;Oliveri et al. 2010;Beardsley et al. 2012;Kiehbadroudinezhad et al. 2014. In particular, Karastergiou et al. (2006) obtained the most appropriate u-v plane sampling for lowdensity interferometers, based on the work of Keto (1997) and Boone (2001Boone ( , 2002, but they did not consider SLL suppression, which is important in astronomy applications to capture a clear image of a radio point source. ...
... The more complicated problem of optimizing a correlator array that satisfies all possible observation conditions, such as suppressed SLL in the angular domain (l-m domain) and uniform coverage in the spatial frequency domain (u-v domain), has been considered only recently by Kiehbadroudinezhad et al. (2014). Therefore, our contribution in the current paper focuses on a new algorithm that optimizes an interferometric array of antennas, in the two main aspects of the u-v sample distribution in the spatial frequency domain in both observations and SLLs in the angular domain, while considering the scientific application goals. ...
... Moreover, with respect to previous methods and algorithms (see, e.g., Kogan 2000;Boone 2001;Sodin & Kopilovich 2002;Cohanim et al. 2004;Su et al. 2004;Karastergiou et al. 2006;Oliveri et al. 2010;Gauci et al. 2013;Kiehbadroudinezhad et al. 2014), Kiehbadroudinezhad et al. (2014) applied the Genetic Algorithm (GA) to correlator arrays. The authors showed that the GA was able to cover the u-v plane more efficiently than the Giant Metrewave Radio Telescope (GMRT) under the same constraints. ...
The Square Kilometre Array (SKA) ushers in the new generation of large radio telescopes that will work at wavelengths between meters and centimeters. In order to competitively design interferometric antenna arrays such as SKA, it is crucial to focus on the optimization of system performance. In this paper, we contribute to the solution by introducing a new optimization algorithm called Division Algorithm (DA). This algorithm finds the optimal positions of antennas to simultaneously maximize u–v coverage and decrease sidelobe level (SLL). The DA is able to optimize the configuration of the interferometric array in both snapshot and Earth rotation synthesis observations. To demonstrate its efficiency, the DA is applied to configure an optimum 30-element array for the Giant Metrewave Radio Telescope. The proposed algorithm is able to improve the overlapped samples parameter by about 4% and the unsampled cells parameter by about 12%, at snapshot observation, compared to the Genetic Algorithm (GA). DA is able to improve these two parameters for a 6-hr tracking observation as well. Finally, the proposed algorithm is compared with the GA for different source declination. Results show that the DA is able to decrease the SLL better than the GA.
