Design optimization of conformal antennas by integrating stochastic algorithms with the hybrid finite-element method

Previous work in antenna optimization has primarily focused on applications of optimization algorithms in conjunction with problem-specific or semi-analytic tools. However, previous developments in fast algorithms now offer the possibility of designs and moreover allow for full flexibility in material specification across three dimensions. As an example, this paper combines genetic algorithms (GA) and simulated annealing (SA) with fast hybrid finite-element boundary integral simulations to develop full three-dimensional (3-D) antenna designs using shape, topology, as well as material optimization. To illustrate these optimization methods as well as compare between GA and SA, three different antenna designs are considered. First, a folded-slot antenna is optimized for broad-band performance, followed by an irregular-shaped dual-band antenna design. As a third design, which combines shape and material optimization, a bandgap substrate is designed to substantially increase the bandwidth of a patch residing on the optimized substrate.