Magnetic nanocomposites for rf applications in mobile communication

本项目旨在开发新型高频磁性材料及其在主要用于移动通信电子的新型高频元件中的应用和评估。移动电子设备对小型化的持续需求以及电子电路频率稳步增加到GHz范围，刺激了高频磁元件的研究。众所周知，高导磁材料可以增加电感的电感，理想情况下是增加材料的相对导磁系数。因此，如果磁性材料不产生额外的损耗，则可以获得电感和质量因数的大幅增加。目前的方法要么存在低导电性、高导电性导致涡流损耗、低铁磁共振频率的问题，要么存在难以在高性能电子元件所需的复杂几何形状中对齐硬轴的问题。根据最近一篇理论论文中提出的路线，我们的方法是基于聚合物基质中的磁性纳米颗粒。如果这种方法成功，它将使我们能够有效地抑制涡流，实现软磁薄膜材料的垂直各向异性，并获得具有合理高频导磁率的非常高的截止频率。该项目包括由Franz Faupel （Kiel大学）团队通过气相共沉积或串联沉积制备这些磁性材料，他在金属-聚合物界面和复合材料方面具有长期的专业知识。磁性和高分辨率透射电子显微镜表征是由Eckhard Quandt （Caesar, Bonn）小组进行的，他是高频材料及其在电子元件中的结合方面的专家。为了证明这些新材料的好处，高频和微波工程专家Reinhard Knöchel（基尔大学）团队将设计不同的电子元件，如电感器和BALUNs，这些元件将使用凯撒的洁净室设施制造。它们的高频特性将由Reinhard Knöchel¿s小组进行表征，该小组将把它们与自己的建模结果和用经典的最先进的薄膜材料获得的数据进行比较。

This project aims at the development of new high frequency magnetic materials and their use and evaluation in novel high frequency components used mainly in mobile communication electronics. The ongoing demand for miniaturization in mobile electronic devices as well as steadily increasing frequencies of electronic circuits into the GHz range have stimulated the research on high frequency magnetic components. It is well known that a highly permeable material can increase the inductance of an inductor, ideally by a factor of the relative permeability of the material. thus a substantial increase in inductance and hence in the quality factor can be obtained if no extra losses are produced by the magnetic material. The current approaches suffer either from low permeabilities, high conductivity leading to eddy current losses, low ferromagnetic resonance frequencies or from difficulties to align the hard axis in complex geometries necessary for high performance electronic components. Following the route suggested in a recent theoretical paper our approach is based on magnetic nanoparticles in a polymer matrix. If this approach is successful it will allow us to effectively suppress eddy currents, to achieve a perpendicular anisotropy in soft magnetic thin film materials and to obtain very high cut-off frequencies with reasonable high frequency permeabilities.The project includes the preparation of these magnetic materials by vapor phase co- or tandem deposition by the group of Franz Faupel (University of Kiel), who has a long-standig expertise in metal-polymer interfaces and composites. The magnetic as well as high resolution transmission electron microscopy characterization is performed by the group of Eckhard Quandt (Caesar, Bonn), who is an expert in high frequency materials and their incorporation in electronic components. To demonstrate the benefits of these new materials the group of Reinhard Knöchel (University of Kiel), a specialist on high frequency and microwave engineering, will design different electronic components such as inductors an BALUNs which will be fabricated using caesar¿s cleanroom facilities. Their high frequency properties will be characterized by Reinhard Knöchel¿s group which will compare them to own modeling results and to the data achieved with classical state-of-the-art thin film materials.