Development and application of ferrite materials for low temperature co-fired ceramic （LTCC） technology are dis- cussed, specifically addressing several typical ferrite materials such as M-type barium ferrite, NiCuZ...Development and application of ferrite materials for low temperature co-fired ceramic （LTCC） technology are dis- cussed, specifically addressing several typical ferrite materials such as M-type barium ferrite, NiCuZn ferrite, YIG ferrite, and lithium ferrite. In order to permit co-firing with a silver internal electrode in LTCC process, the sintering temperature of ferrite materials should be less than 950 ℃. These ferrite materials are research focuses and are applied in many ways in electronics.展开更多
Magnesium-substituted Mn0.8Zn0.2Fe2O4 ferrite is synthesized by the sol–gel combustion method using citrate acid as the complex agent. The electromagnetic absorbing behaviors of ferrite/polymer coatings fabricated by...Magnesium-substituted Mn0.8Zn0.2Fe2O4 ferrite is synthesized by the sol–gel combustion method using citrate acid as the complex agent. The electromagnetic absorbing behaviors of ferrite/polymer coatings fabricated by dispersing Mn–Zn ferrite into epoxy resin （EP） are studied. The microstructure and morphology are characterized by X-ray diffraction and scanning electron microscope. Complex permittivity, complex permeability, and reflection loss of ferrite/EP composite coating are investigated in a low frequency range. It is found that the prepared ferrite particles are traditional cubic spinel ferrite particles with an average size of 200 nm. The results reveal that the electromagnetic microwave absorbing properties are significantly influenced by the weight ratio of ferrite to polymer. The composites with a weight ratio of ferrite/polymer being 3：20 have a maximum reflection loss of –16 dB and wide absorbing band. Thus, the Mn–Zn ferrite is the potential candidate in electromagnetic absorbing application in the low frequency range （10 MHz–1 GHz）.展开更多
The present paper analyses the effect of placing the ferrite magnet into the rotor air barrier of synchronous reluctance generators(SRG)on its electromagnetic performance.The paper uses a difference of average electro...The present paper analyses the effect of placing the ferrite magnet into the rotor air barrier of synchronous reluctance generators(SRG)on its electromagnetic performance.The paper uses a difference of average electromagnetic torque and ripple torque as a measure of the performance index.Here,in the analysis,a magnetic material is placed in the middle of each air barrier,and its size is symmetrically increased on both sides to increase the percentage of the volume of the magnetic material.The effect of an increase in the volume of the magnetic material on its performance is presented.Moreover,the variation in electromagnetic features such as the d−and q-axes inductance and flux linkage are also explored and compared for different volumes and ferrite material.In the present work,finite element analysis is used to get the electromagnetic performance.The paper also includes hardware validation on the fabricated prototype of SRG(without ferrite magnet),but SRG with a ferrite magnet only includes the results with FEA simulation.展开更多
The electromagnetic properties of Ba2Co1.8Cu0.2Fe12O22 （Co2Y） and Ba3Co2Fe23.4Zn0.6O41 （Co2Z） were studied by measuring microwave scattering parameters.In the transmission spectra of Ba2Co1.8Cu0.2Fe12O22,a forbidd...The electromagnetic properties of Ba2Co1.8Cu0.2Fe12O22 （Co2Y） and Ba3Co2Fe23.4Zn0.6O41 （Co2Z） were studied by measuring microwave scattering parameters.In the transmission spectra of Ba2Co1.8Cu0.2Fe12O22,a forbidden band emerges due to ferromagnetic resonance,and the permeability will turn to negative in the vicinity of the ferromagnetic resonance frequency.In the complex permittivity spectra of Ba3Co2Fe23.4Zn0.6O41,the negative permittivity can be obtained due to dielectric resonance.Therefore,Co2Y and Co2Z can be used to construct left-handed materials possessing negative permeability and negative permittivity simultaneously.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2012CB933100)the National Natural Science Foundation of China(Grant Nos.51132003,61021061,and 61171047)the Second Item of Strongpoint Industry of Guangdong Province,China(Grant No.2012A090100001)
文摘Development and application of ferrite materials for low temperature co-fired ceramic （LTCC） technology are dis- cussed, specifically addressing several typical ferrite materials such as M-type barium ferrite, NiCuZn ferrite, YIG ferrite, and lithium ferrite. In order to permit co-firing with a silver internal electrode in LTCC process, the sintering temperature of ferrite materials should be less than 950 ℃. These ferrite materials are research focuses and are applied in many ways in electronics.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20121101110014)
文摘Magnesium-substituted Mn0.8Zn0.2Fe2O4 ferrite is synthesized by the sol–gel combustion method using citrate acid as the complex agent. The electromagnetic absorbing behaviors of ferrite/polymer coatings fabricated by dispersing Mn–Zn ferrite into epoxy resin （EP） are studied. The microstructure and morphology are characterized by X-ray diffraction and scanning electron microscope. Complex permittivity, complex permeability, and reflection loss of ferrite/EP composite coating are investigated in a low frequency range. It is found that the prepared ferrite particles are traditional cubic spinel ferrite particles with an average size of 200 nm. The results reveal that the electromagnetic microwave absorbing properties are significantly influenced by the weight ratio of ferrite to polymer. The composites with a weight ratio of ferrite/polymer being 3：20 have a maximum reflection loss of –16 dB and wide absorbing band. Thus, the Mn–Zn ferrite is the potential candidate in electromagnetic absorbing application in the low frequency range （10 MHz–1 GHz）.
文摘The present paper analyses the effect of placing the ferrite magnet into the rotor air barrier of synchronous reluctance generators(SRG)on its electromagnetic performance.The paper uses a difference of average electromagnetic torque and ripple torque as a measure of the performance index.Here,in the analysis,a magnetic material is placed in the middle of each air barrier,and its size is symmetrically increased on both sides to increase the percentage of the volume of the magnetic material.The effect of an increase in the volume of the magnetic material on its performance is presented.Moreover,the variation in electromagnetic features such as the d−and q-axes inductance and flux linkage are also explored and compared for different volumes and ferrite material.In the present work,finite element analysis is used to get the electromagnetic performance.The paper also includes hardware validation on the fabricated prototype of SRG(without ferrite magnet),but SRG with a ferrite magnet only includes the results with FEA simulation.
基金supported by the National Natural Science Foundation of China (No.50702005)the Basic and Frontier Research Programs of Henan Province,China (No.092300410242)the Natural Science Foundation of the Education Department of Henan Province,China (No.2010A430012)
文摘The electromagnetic properties of Ba2Co1.8Cu0.2Fe12O22 （Co2Y） and Ba3Co2Fe23.4Zn0.6O41 （Co2Z） were studied by measuring microwave scattering parameters.In the transmission spectra of Ba2Co1.8Cu0.2Fe12O22,a forbidden band emerges due to ferromagnetic resonance,and the permeability will turn to negative in the vicinity of the ferromagnetic resonance frequency.In the complex permittivity spectra of Ba3Co2Fe23.4Zn0.6O41,the negative permittivity can be obtained due to dielectric resonance.Therefore,Co2Y and Co2Z can be used to construct left-handed materials possessing negative permeability and negative permittivity simultaneously.
