Synthesis of Shaped, Reconfigurable, and Envelope Beam for Linear Array Using a Hybrid Whale Optimization Algorithm
Pengliang Yuan
Whale optimization algorithm (WOA) has been demonstrated to be a powerful strategy for various kinds of optimized problems. However, the direct use of WOA to tackle the shaped pattern synthesis can not reach the satisfactory result. To overcome this problem, a hybrid whale optimization algorithm(HWOA) is proposed in this paper, through integrating the invasive weed optimization (IWO) and hyper chaotic system into the standard WOA to improve the population diversity and convergence speed. To demonstrate the performance of HWOA, various runs of tests are conducted for the most widely used benchmark functions. The statistical result shows that the proposed HWOA can attain a superior performance, in comparison with other state-of-the-art algorithms. To investigate the effectiveness and feasibility of the proposed HWOA in the linear array synthesis, the simulation experiments for synthesis of shaped, reconfigurable and envelope pattern in the main and side lobe are done, and the corresponding numerical results are provided. In the shaped beams synthesis, the specified PSLL and maximal ripple are respectively -25 dB and 1 dB, and HWOA has a PSLL improvement of 0.2 dB and a ripple improvement of 0.27 dB. For the reconfigurable beams synthesis, the technique specification is the same as the shaped beams synthesis. The optimal PSLL reaches -25.57 dB, and the optimal ripple is 0.3873 dB. For the envelope synthesis, the main lobe region of line envelop lies in θ ∈ [85°, 95°], and the side lobe levels are decreased from -30 dB to -40 dB along a line. The maximal error of the optimal result is only 0.2dB. In particular, a new form of fitness function to facilitate the envelope synthesis is also presented.
