Measurement, characterization, simulation and optimization of a coplanar isolator for microwave applications

New passive components for microwave applications above 30 GHz currently have the major defect not to be compatible with industrial integration. Their performances are often ruined either when it is needed to reduce their dimensions or when some of their materials cannot be deposited in the requested conditions. This study takes a coplanar isolator working at 50 GHz and with barium hexaferrite thin film as an illustration of this problem. The component, which has been fabricated at the laboratory by RF sputtering of the different layers which stacks it up, shows very interesting characteristics. However, much work remains on the increasing of its isolation capacity as well as on its miniaturization. All of the component's dealings are here presented. Its behaviour has been revealed experimentally performing on-wafer measurements with a probe system coupled with a vector network analyser. The measurement technique is explained beforehand and then validated by further simulation results. The modelling of the component is tackled also and the obtained model serves as a basis for optimization investigations. In that matter, an innovative approach is introduced which leads to the use of currently emerging metamaterials technology. Finally, conclusions are drawn on the real opportunity that such new composite materials can be.