Authors : Saad S. Hreshee and Israa Mohamed
Abstract: Time Modulated Array (TMA) is an electromagnetic system that radiates a controlled power pattern. The process of the array has a non-linear nature which causes the appearance of unwanted side lobes. This study presents two algorithms with two schemes to reduce the side lobes level. The first algorithm is the Invasive Weed Optimization (IWO). While the second one is the Particle Swarm Optimization (PSO). Different numbers of array elements (4, 8, 16, 32, 64) are used and tested in this research. In the first scheme (one stage), each algorithm is used alone in one stage to achieve maximum power in the antenna pattern direction by reducing the side lobe level to the lowest value. The results appeared that the IWO algorithm reduced side lobe level to -40.53 dB at N = 64 and it is better than PSO algorithm which reduced the side lobe level to -25.49 dB. The second scheme (two stages) the algorithms used in double stages with four cases IWO-IWO, IWO-PSO, PSO-IWO and finally PSO-PSO. In the two stages scheme, the results showed that the IWO-IWO scheme is better than other schemes which reduced the SLL to -43.19 dB.
Saad S. Hreshee and Israa Mohamed, 2018. Reduction of Side Lobe Level in a Time-Modulated Linear Array Using Invasive Weed Optimization and Particle Swarm Optimization. Journal of Engineering and Applied Sciences, 13: 11048-11054.