DESIGN OF DIELECTRIC RESONATOR ANTENNAS USING SURROGATE-BASED OPTIMIZATION AND ELECTROMAGNETIC MODELS

Design of dielectric resonator antennas (DRAs) is a challenging task because their analytical models are only appropriate for estimation, i.e., to calculate the resonance frequency and radiation quality factor of an isolated dielectric resonator or for obtaining an initial design. In practice, the geometry parameters that ensure satisfaction of performance requirements are often obtained by repetitive electromagnetic (EM) simulations guided by engineering experience. This is a tedious process, and it does not guarantee optimal results. On the other hand, employing the EM solver directly in the optimization loop is typically impractical because high-fidelity EM simulations are computationally expensive. Here, we describe several techniques that allow designing DRAs in a computationally efficient way. All presented methods exploit coarse-discretization EM models of the DRA. These models, after correction, serve as prediction tools that guide the optimization process. As the low-fidelity models are computationally much cheaper than the original, high-fidelity ones, the cost of the design process is greatly reduced. The approaches presented here include adaptively adjusted design specifications, shape-preserving response prediction, and space mapping with kriging-based coarse models. Antenna design examples are provided.