An equivalent circuit for a novel RF integrated inductor with ferrite thin-film is derived. The enhancement of the magnetic ferrite thin-film on the inductance （L） and quality factor （Q） of the inductor is analyze...An equivalent circuit for a novel RF integrated inductor with ferrite thin-film is derived. The enhancement of the magnetic ferrite thin-film on the inductance （L） and quality factor （Q） of the inductor is analyzed. Circuit element parameters are extracted from RF measurements. Compared with the reference air-core inductor without magnetic film, L and Q of the ferrite thin-film inductor are 17% and 40% higher at 2GHz,respectively. Both the equivalent circuit analysis and test results demonstrate significant enhancement of the performance of RF integration inductors by ferrite thin-film integration.展开更多
Yttrium iron garnet （YIG） is widely used for microwave ferrite devices, especially for optical isolators. In this paper, ferrite ceramic target using cerium （Ce）-substituted YIG was made using ferric oxide （Fe203...Yttrium iron garnet （YIG） is widely used for microwave ferrite devices, especially for optical isolators. In this paper, ferrite ceramic target using cerium （Ce）-substituted YIG was made using ferric oxide （Fe203）, cerium oxide （CeO2） and yttrium oxide （Y2O3） powders as raw material. Ce： YIG thin films were fabricated by radio frequency （RF） magnetron sputtering. The experimental result showed that the polycrystalline YIG was obtained after sintering at 1 350 ℃ for 6 h, and the polycrystalline Ce： YIG thin films were achieved annealing up to 700 ℃ in the air.展开更多
We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for ...We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for the inforcom technologies. GHz magnetic properties of the soft magnetic thin films with in-plane anisotropy were investigated. It is found that several hundreds of permeability at the GHz frequency was achieved for Col00_xZrx and Co90Nbl0 metallic thin films because of their high satu- ration magnetization, and an adjustable resonance frequency from 1.3 to 4.9 GHz was obtained. Compared with the metallic thin films, the weaker saturation magnetization of Ni-Zn ferrite thin films results in several tens of permeability at the GHz frequency, but the larger resistivity of the ferrite prepared in situ without any heating treatments has lower energy loss. In order to obtain materials with large permeability and low energy loss in the GHz range, the [CoFe-NiZn ferrite] composite granular thin films were investigated, where the advantage of higher saturation magnetization for the metallic alloy and the high resis- tivity as well as high saturation magnetization for the ferrite results in a good GHz magnetic performance.展开更多
The microstructure and magnetic properties of cobalt ferrite thin films deposited by the sputtering method on an Fe3o4 un- der-layer were investigated at different post-annealing temperatures. Results show that the Fe...The microstructure and magnetic properties of cobalt ferrite thin films deposited by the sputtering method on an Fe3o4 un- der-layer were investigated at different post-annealing temperatures. Results show that the Fe3o4 under-layer can accelerate the grain growth of cobalt ferrite films due to the phase transformation of the Fe3o4 under-layer at about 400℃-500℃. By intro- ducing the Fe3O4 under-layer, cobalt ferrite nanocrystalline thin films with high coercivity can be obtained at lower post-annealing temperatures.展开更多
文摘An equivalent circuit for a novel RF integrated inductor with ferrite thin-film is derived. The enhancement of the magnetic ferrite thin-film on the inductance （L） and quality factor （Q） of the inductor is analyzed. Circuit element parameters are extracted from RF measurements. Compared with the reference air-core inductor without magnetic film, L and Q of the ferrite thin-film inductor are 17% and 40% higher at 2GHz,respectively. Both the equivalent circuit analysis and test results demonstrate significant enhancement of the performance of RF integration inductors by ferrite thin-film integration.
基金National Natural Science Foundation of China(NSFC)(No.51175418)Program for New Century Excellent Talents in University(No.93JXDW02000006)+4 种基金Natural Science Foundation of Shaanxi Province(No.2011JQ7004)Fundamental Research Funds for the Central Universities of Xi'an Jiaotong University(No.2011jdgz09No.2011jdhz23No.xjj2011068)Fund of the State Key Laboratory of Digital Manufacturing Equipment & Technology(No.DMETKF2012009)
文摘Yttrium iron garnet （YIG） is widely used for microwave ferrite devices, especially for optical isolators. In this paper, ferrite ceramic target using cerium （Ce）-substituted YIG was made using ferric oxide （Fe203）, cerium oxide （CeO2） and yttrium oxide （Y2O3） powders as raw material. Ce： YIG thin films were fabricated by radio frequency （RF） magnetron sputtering. The experimental result showed that the polycrystalline YIG was obtained after sintering at 1 350 ℃ for 6 h, and the polycrystalline Ce： YIG thin films were achieved annealing up to 700 ℃ in the air.
基金supported by the National Natural Science Foundation of China (Grant No. 11034004)National Science Fund for Distinguished Young Scholars (Grant No. 50925103)+1 种基金Key Grant Project of Chinese Ministry of Education (Grant No. 309027)the Fundamental Research Funds for the Central Universities (Grant No. lzujbky-2010-219)
文摘We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for the inforcom technologies. GHz magnetic properties of the soft magnetic thin films with in-plane anisotropy were investigated. It is found that several hundreds of permeability at the GHz frequency was achieved for Col00_xZrx and Co90Nbl0 metallic thin films because of their high satu- ration magnetization, and an adjustable resonance frequency from 1.3 to 4.9 GHz was obtained. Compared with the metallic thin films, the weaker saturation magnetization of Ni-Zn ferrite thin films results in several tens of permeability at the GHz frequency, but the larger resistivity of the ferrite prepared in situ without any heating treatments has lower energy loss. In order to obtain materials with large permeability and low energy loss in the GHz range, the [CoFe-NiZn ferrite] composite granular thin films were investigated, where the advantage of higher saturation magnetization for the metallic alloy and the high resis- tivity as well as high saturation magnetization for the ferrite results in a good GHz magnetic performance.
基金supported by the National Natural Science Foundation of China (Grant No. 61071028)the NCET (Grant No. 08-0089)the RFDP (Grant No. 20100185110024)
文摘The microstructure and magnetic properties of cobalt ferrite thin films deposited by the sputtering method on an Fe3o4 un- der-layer were investigated at different post-annealing temperatures. Results show that the Fe3o4 under-layer can accelerate the grain growth of cobalt ferrite films due to the phase transformation of the Fe3o4 under-layer at about 400℃-500℃. By intro- ducing the Fe3O4 under-layer, cobalt ferrite nanocrystalline thin films with high coercivity can be obtained at lower post-annealing temperatures.
