International Core Journal of Engineering 2020-26 | Page 211

2019 International Conference on Artificial Intelligence and Advanced Manufacturing (AIAM) The Optimization of Uniform Concentric Ring Array Using Improved Simulated Annealing Algorithm Feng Zhang Xueqing Yang Quanliang Huang Junwu Tao Department of Advanced Engineering Development DongFeng Commercial Vehicle Technical Center Wuhan, China [email protected] Department of Electronic Information and Communications Huazhong University of Science and Technology Wuhan, China [email protected] Department of Electronic Information and Communications Huazhong University of Science and Technology Wuhan, China [email protected] Laboratory Plasma and Conversion Energy INP Toulouse, Toulouse University Toulouse, France [email protected] constraints of the minimum element spacing, total element number, and aperture size into account, is established. On the other side, many optimization methods, such as genetic algorithm (GA) [9], differential evolution (DE) [10], simulated annealing algorithm (SA) and swarm intelligence algorithms [11], have been successfully applied to the unequally spaced array synthesis with a minimum element spacing constraint. Abstract—In this paper, a novel modified objective function is proposed, which represents a novel approach for optimization problems of uniform concentric ring arrays (UCA). Improved simulated annealing algorithm (SA) has been applied to the proposed method. The results obtained by the novel modified objective function are compared with those obtained by the objective function proposed by Cornwell. Numerical comparison results have been carried out to demonstrate the validity and outperformance of this new proposed approach. The design of optimization objective function of UCA was first proposed by Cornwell, which used maximizing the distance between spatial frequency coverage samples as objective function. However, huge computational efforts are inevitable for the approach since the problem size grows rapidly as the element number increasing and the baseline distribution in the area are intermittent. Keywords—modified objective function, uniform concentric ring arrays (URA), optimization, simulated annealing algorithm (SA) I. I NTRODUCTION Synthetic aperture imaging radiometer(SAIR) has capability of providing high-resolution image of moving targets to make it has a wide used in application of earth observation, such as ESTAR [1], MIRAS [2] , GeoSTAR [3], and GIMS [4] . One of the most important parts of the design of radio-interferometric arrays for SAIR is the choice of the optimum layout of the receiving elements [5]. Planar arrays provide more control over the radiation pattern compared with linear arrays. Though various types of planar arrays, such as “ Y, T, U, circle” , concentric ring arrays (CRA) have been widely used in applications of satellite communications and radio-astronomy since it has many advantages in terms of significant reduction in weight and cost of the antenna system, increasing resolution and reducing array redundancy[6]. However, many methods that are based on the linear periodicity of elements are unable to deal with the difficulty of the calculations because of the characteristics of such arrays. Thus, it is very important to take optimization tools for the synthesis of such arrays. In this paper, a novel modified objective function is proposed, which uses the minimum distance of adjacent elements as the objective function and has advantages in meeting the minimum element spacing constraint and forming a uniform UV sampling coverage. Simulated annealing algorithm (SA) has been applied to the proposed method. Nevertheless, there is a contradiction between the optimal solution and the solution time cost in SA algorithm, it will have extremely time consumption as the numbers of antennas increasing. In this paper, SA algorithm is optimized to make it suitable for solving the novel objective functions. Several comparisons of numerical results between the novel modified objective function and the objective function proposed by Cornwell demonstrate the flexibility and outperformance of this new proposed approach. II. M ETHODOLOGY OF THE PROPOSED METHOD A. Modified Objective Function The design of UCA optimization objective function was first proposed by Cornwell, the objective function is expressed as: In recent years, a variety of the optimization of uniform concentric ring arrays (UCA) have been presented. In [7], a two-dimensional (2-D) deterministic approach (DA) for fast design of the density-tapered CRAs is proposed, which has advantages of computationally efficient. In [8], a novel hybrid approach (HA) to synthesize uniform amplitude concentric ring arrays (UACRAs), which aim at minimizing the PSLL for pencil beams and take array parameter 978-1-7281-4691-1/19/$31.00 ©2019 IEEE DOI 10.1109/AIAM48774.2019.00045 E ( r 1 , r 2 ,..., r N ) N ¦ log( i , j , k , l 1 189 ( u ij  u kl ) 2  ( v ij  v kl ) 2 ) (1)