Simplified Method of Measuring Magnetic Permeability Temperature Profile for RF Device Applications
Ferrite is popular as a core material for RF transformers. Since transmission characteristics of RF transformers are affected by the core’s permeability, which has a large temperature dependence, the development of a method for measuring the core permeability temperature profile is important. In this study, a temperature profile measurement of ferrite core permeability has been investigated using a microstrip line method which has the advantage of the circuit being compact in size and therefore suitable for measuring temperature profiles. Based on the results measured with a sample ferrite core, the temperature dependence of RF transformer performance (isolation) is also discussed. Furthermore, basic results of experiments to compensate for the degradation in isolation is presented.
Pietro VINCENZINI, Vojislav V. MITIC, Alois LOIDL and Dino FIORANI
A. Kuramoto et al., "Simplified Method of Measuring Magnetic Permeability Temperature Profile for RF Device Applications", Advances in Science and Technology, Vol. 67, pp. 118-123, 2010