A study on pattern synthesis method for array-fed reflector antenna for advanced direct broadcasting satellites

Author(s):  
S. Tanaka ◽  
T. Yamada ◽  
T. Murata ◽  
T. Nomoto ◽  
H. Matsumura
2011 ◽  
Vol 30 (3) ◽  
pp. 738-741
Author(s):  
Xia Zhang ◽  
Hai-hong Tao ◽  
Gui-sheng Lian

2014 ◽  
Vol 7 (6) ◽  
pp. 775-781 ◽  
Author(s):  
Anirban Chatterjee ◽  
Gautam Kumar Mahanti ◽  
Narendra Nath Pathak

Thinning a large concentric ring array by an evolutionary algorithm needs to handle a large amount of variables. The computational time to find out the optimum elements set increases with the increase of array size. Moreover, thinning significantly reduces the directivity of the array. In this paper, the authors propose a pattern synthesis method to reduce the peak sidelobe level (peak SLL) while keeping first null beamwidth (FNBW) of the array fixed by thinning the outermost rings of the array based on Gravitational Search Algorithm (GSA). Two different cases have been studied. In the first case only the outermost ring of the array is thinned and in the second case the two outermost rings are thinned. The FNBW of the optimized array is kept equal to or less than that of a fully populated, uniformly excited and 0.5 λ spaced concentric ring array of same number of elements and rings. The directivity of the optimized array for the above two cases are compared with an array optimized by thinning all the rings, while keeping the design criteria same as the above two cases. The optimized array by thinning the outermost rings gives higher directivity over the optimized array by thinning all the rings. Time required for computing the optimum elements state for the above two cases using GSA are shown lesser compared to the optimized array by thinning all the rings using the same algorithm. The peak SLL and the FNBW of the optimized array for the above two cases are also compared with the optimized array by thinning all the rings.


2015 ◽  
Vol 43 ◽  
pp. 147-156 ◽  
Author(s):  
Youji Cong ◽  
Guonian Wang ◽  
Zhengdong Qi

2014 ◽  
Vol 7 (5) ◽  
pp. 565-570 ◽  
Author(s):  
Seyed Mohammad Alavi ◽  
Ali F. Naini

This paper presents a comparison between three evolutionary algorithms (EAs) for pattern synthesis of offset reflector antenna fed by a planar array of horn antennas. To perform the optimization process, an elliptical-shaped beam in the U–V plane (U = sinθ cosφ and V = sinθ sinφ) is considered as the desired far-field radiation pattern. To attain the appropriate excitation value for array elements, three conditions are considered: (1) variable amplitude (with uniform phase distribution), (2) variable phase (with uniform amplitude distribution), and (3) variable amplitude and phase excitation. Obtaining the appropriate excitation value based on the mathematical methods is always complicated and time-consuming. Therefore, genetic algorithm (GA) and particle swarm optimization (PSO) as two well-known EAs have been used widely for different applications and shown the promise to solve complicated problems. This paper compares these two EAs with invasive weed optimization (IWO) which is robust and has simple and powerful process with few tuning parameters. We found that for pattern synthesis of multi-feed reflector antenna in different conditions, IWO can provide accurate and comparable results with GA and PSO methods at approximately same iteration number. The convergence diagrams as well as the optimized radiation patterns for different conditions are presented and compared for GA, PSO and IWO.


2016 ◽  
Vol 5 (3) ◽  
pp. 86 ◽  
Author(s):  
D. Mandal ◽  
K. S. Kola ◽  
J. Tewary ◽  
V. P. Roy ◽  
A. K. Bhattacharjee

In this paper a pattern synthesis method based on Evolutionary Algorithm is presented. A Flat-top beam pattern has been generated from a concentric ring array of isotropic elements by finding out the optimum set of elements amplitudes and phases using Differential Evolution algorithm. The said pattern is generated in three predefined azimuth planes instate of a single phi plane and also verified for a range of azimuth plane for the same optimum excitations. The main beam is steered to an elevation angle of 30 degree with lower peak SLL and ripple. Dynamic range ratio (DRR) is also being improved by eliminating the weakly excited array elements, which simplify the design complexity of feed networks.


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