Ontwerp van metamaterialen en toepassing in antennes

Metamaterials have received increasing attention due to their unique electromagnetic properties. Various types of metamaterial have been proposed with different characteristics, e.g. negative refractive index, huge chirality, magnetic conductivity, etc. These unusual properties play an important role in modern antenna design, which can provide better performance, more functions, and more flexibility. The main target of this PhD is to deeply study the characteristics of metamaterials, and to use that to improve the performance of microwave antennas. Three types of metamaterial are proposed, i.e. the coated dielectric sphere-based metamaterial with a wide negative refractive index band, the encapsulating metamolecule with high quality factor, and the planar coupled resonators with huge chirality. Different physical parameters are studied for these topologies with both numerical and measured results, and the working mechanisms behind these phenomena are explained by studying current and field distributions. Some potential applications of these structures are also discussed. Then, several antennas based on metamaterials are designed, including dual-band textile patch antennas based on the linear composite right/left-handed transmission line, radial patch antennas operating at zeroth-order mode and negative modes, and low profile antennas loaded with an artificial magnetic conductor plane. All the antennas are designed using simulations and verified through experiments. Their performances improve compared with conventional antennas.nrpages: 163status: publishe