The driven eigenproblem computation with the Brent method acceleration

The driven eigenproblem computation is an efficient method to solve the eigenproblems of periodic structures like substrate integrated waveguides (SIWs) or metamaterials by treating the unit cell of the structure as a resonator. The analogy between the eigenproblem and the resonance opens up the possibility to convert the eigenproblem into a driven resonator problem by providing an excitation. The dispersion and attenuation curves of periodic structures are obtained by monitoring the resonance behavior, e.g. based on the electric field or the transmitted power. The speed of resonance allocation determines the speed of the eigenproblem solving procedure. In this paper, the Brent´s extremum searching procedure is utilized to accelerate the driven eigenproblem computation in the hybrid finite element boundary integral (FEBI) method.