Evaluation of Stochastic Algorithm Performance on Antenna Benchmark Problems

at , with a directivity value of 3.32, and the higher local maximum is located at , with a directivity of 3.26. Another significant local maximum results at ( , 1.09), of directivity 3.10. Thus, this problem represents a typical case of two-dimensional (2-D) unimodal optimization function with a strong local maximum and, moreover, accomplishes all the additional features, mentioned above, that a test problem should have. Therefore, we include it in the numerical test-suite proposed n this paper. It will serve to investigate whether the EAs remains stalled at either strong or weak local maxima instead of reaching the global maximum. The wire dipoles were simulated with NEC using approximately 100 segments per wavelength, with an even number of segments so that the feeding voltage is connected at its corresponding two central segments, and od l s a delta-gap source. The radius of the wires was . The search space was formed with the length of the dipoles varying from to and the observation angle from 0 to radians.