High frequency meta-ferroelectrics by inverse design

Composites with subwavelength features exhibit effective properties that depend on microstructure morphology and materials, which can be adjusted to obtain enhanced characteristics. We detail the systematic design of electromagnetic metamaterials composed of dielectric inclusions in a ferroelectric matrix that, under an applied voltage, present an optimized effective tunability higher than the bulk due to a nonlinear local electric field enhancement. The effect of volume fraction, losses, and biasing field on homogenized properties is investigated and the analysis of the photonic band diagram is carried out, providing the frequency dependence of the anisotropic effective index and tunability. Such metaceramics can be used in microwave antennas and components with higher reconfigurability and reduced power consumption.