Application of Invasive Weed Optimization to Design a Broadband Patch Antenna With Symmetric Radiation Pattern

In this letter, we present a patch antenna over a high impedance surface (HIS) substrate, using Jerusalem cross-shaped frequency selective surfaces (JC-FSSs). The objective in this design is to obtain the enhancement in bandwidth (BW) while achieving the symmetric radiation pattern over the frequency band of interest. In order to derive optimal dimensions of the patch antenna and JC-FSS parameters, a hybrid optimization algorithm that originates from invasive weed optimization (IWO) empowered with the analytical lumped circuit model has been employed. In general, we utilized the IWO features while proposing additional contributions in terms of efficient design and computational efficiency. The optimization benefits from the use of circuit model as a powerful tool to find specific limits for its variables. Therefore, it provides a reasonable starting point for the optimization procedure. For the most efficient design, the antenna and FSS ground plane are optimized simultaneously. In this case, the optimization time can be noticeably reduced. The simulations compared very well with measured results. This antenna shows relative bandwidth 10.44% with the radiation efficiency of better than 85% over the entire bandwidth.