Optimization of a Novel Nano Antenna With Two Radiation Modes Using Kriging Surrogate Models

In this paper, a novel nano antenna with two radiation modes is introduced. The structure of this nano antenna consists of a ring coupler and two patch antennas placed on a SiO2 substrate. The direction of the main lobe of the radiation pattern of this nano antenna can be adjusted to be either in the broadside or the endfire direction. The proposed nano antenna is optimized to minimize the losses and to maximize the radiation efficiency in addition to achieve maximum discrimination between the two desired directions of the main beam. In optimizing the proposed structure, the computationally expensive full-wave electromagnetic simulation is replaced by cheaper surrogate models, which are kriging models. Two optimization techniques, namely multi-objective particle swarm with preference ranking organization METHod for enrichment evaluations method and design centering using the normed distances, are used to obtain the optimal values of the design parameters. A convergence test is performed to ensure the validity of the obtained simulation results. A sensitivity analysis is performed to show how the manufacturing tolerance in each design parameter is affecting the performance of the proposed nano antenna.