Measuring the permeability of magnetic materials in the GHz region

Abstract

Abstract Magnetic materials have always been important in the commercial world and, as our transport systems are switching to electrification from fossil fuels, they are likely to become more so. Relative permeability, μ r, is one parameter which characterizes such materials and this article discusses some measurements of μ r, made on powdered iron oxide and two ferrite magnetic materials. Preliminary measured values of μ r range from 1.5 to 4 and the imaginary part of μ r, show that magnetic losses occur in the GHz region. An idea for improved measurements is suggested.