Microwave properties of diluted composites made of magnetic wires with giant magnetoimpedance effect

Free space permittivity measurements are presented on lattices of magnetic microwires . It is shown that the magnetic properties strongly affect the dielectric response of the composite. A model is presented, that accounts for these observations. The microwave dielectric function is shown to depend on the microwave impedance of the wire. Previous works on giant magneto impedance have provided a strong theoretical and experimental background, that may now be used to design composites with complex dielectric response, and also tuneable response. Some principles for making tuneable composites are presented, and illustrated by experimental results.