Miniaturized Broadband Antenna Design via Simp

Design optimization for electromagnetic applications has traditionally been a process based on the creativity and past experience of the designer focusing mainly on size optimization. Recent advances in fast and rigorous full wave simulators and the concurrent availability of inexpensive manufacturing techniques for intricate shape and composite materials provides the opportunity to revolutionize traditional design optimization processes to topology and material optimization. So far, examples in the literature on topology optimization of electrical devices have dealt with restricted or semi-analytic tools for magneto-static applications [1]. In this paper, we introduce the mathematical framework for optimizing the topology of dielectric substrates using the SIMP method. As an example, the SIMP method is extended here to design the material distribution of a dielectric substrate of a patch antenna subject to pre-specified bandwidth and miniaturization criteria. To our knowledge, this is the first ever integration of material topology optimization for performance improvement of RadioFrequency (RF) applications. A key element of this extension is the use of the latest fast algorithms recently introduced in the FE-BI formulation [2]. For design optimization, the Sequential Linear Programming (SLP) and an exact sensitivity analysis based on the adjoint method is employed. The sensitivity analysis is crucial to integrating the solver, which is based on complex valued functions with the SLP optimizer.