Helle, guys! Right now, I am using fminsearch in Matlab as the optimizer to optimize a slotted substrate integrated waveguide (SIW) antenna. There are 8 longitudinal slots in the SIW H-plane as shown in Fig.1, in order to realize a Taylor distribution with -25 dB sidelobe level. So there are 16 variables in total to be optimized, including each slot's offset length (xi) and length (li), while setting its width (w) and slot interval (l01, l02,...) to constant. As a result, the optimization process is very upset as shown in Fig. 2. It's found the capability of the fminsearch is very weak and the variables only take little change in thousands. Few good solutions can be found in the optimization process. So I'd like to ask is there any better strategy to optimize such a problem? Hopping some optimization masters can give me some hints to improve the optimization efficiency.
Figure 1 SIW Slotted Antenna with Varibles Illustration
Figure 2 Optimization Process with Fitness Function Value versus Iteration Step
