Low field magnetoimpedance in the GHz range

In this paper we investigate different aspects of the high-frequency magnetoimpedance at low fields. In the first place, we will study this effect from a phenomenological point of view, comparing it with the low-frequency microwave absorption. The results, discussed in terms of an analytical description of the experiments, prove that both effects respond to the same physical causes. In the second place, we will explore the potential of the high-frequency GMI for sensing applications. The measurements, performed at 3 GHz, show that the sensitivity of the magnetoimpedance only drops due to the growth of the external inductance. However, after a proper minimization of the imaginary part (achieved by means of a matching network), the GMI proves to be as sensitive as it is in the hundreds of MHz.