Study On Ion Substituted YIG Materials And Their Applications

With the development of electronic information technology,various microwave ferrite devices are more and more widely used,which requires ferrite materials for device fabrication to have better performance.YIG material is a kind of important material used in rotating ferrite devices.The development of low loss YIG materials has gradually become a very hot topic.In this thesis,YIG samples with Ca²⁺Sn⁴⁺substitution,Zn²⁺Sn⁴⁺substitution and iron deficiency were obtained by solid-state sintering.Research results show that an appropriate amount of calcium tin ion doping could increase the saturation magnetization of the material.The minimum saturation magnetization value of the samples is 1840 Gs and the maximum is 2080 Gs.The doping of tin ion can reduce the ferromagnetic resonance linewidth of the material.The linewidth decreases the most when the sintering temperature is 1380?and the lowest linewidth value is 21 Oe.Calcium tin co-doping has little effect on the dielectric constant of the material,which is stable at 15,and the dielectric loss tangent values of the samples are between 4×10^-3to4.5×10^-3.Zinc tin ion doping could significantly reduce the saturation magnetization of the material.The minimum saturation magnetization value of the samples is 1447 Gs and the maximum is 1796 Gs.Zinc Tin co-doping can slightly reduce the linewidth value of the material,and the minimum value is 42 Oe.When the sintering temperatures is 1380?or 1400?,the linewidth increases significantly with the increase of doping content,and the linewidth value of the material is stable at 45 Oe when the sintering temperatures is 1420?.The maximum dielectric loss tangent value of zinc tin doped samples is 6×10^-4,the minimum is 3.4×10^-4.Iron deficiency formula could produce YFe O₃heterophase,the porosity of the sample increases significantly and the density decreases.The 4?Ms value of calcium tin doped iron deficiency formula decreased to1630 Gs,the linewidth value increase significantly,and the minimum value is 81 Oe.The dielectric constant of these samples are stable,and the dielectric loss tangent value decreases to 3.4×10^-4.The 4?Ms value of zinc tin doped iron deficiency formula decreased to 1292 Gs,the linewidth increased significantly,and the minimum value is100 Oe.The dielectric constant of these samples are stable,and the dielectric loss tangent value decreases to 4.2×10^-4.Based on the basic principle of circulator designing and using self-made YIG material,a microstrip junction circulator with central working frequency at 9.5 GHz is designed.An actual circulator was made by screen printing process,and its test results from vector network analyzer were as follows:when the range of frequency band is between 8.6 to 9.88 GHz,the insertion loss is no more than 0.6 d B and the isolation is no more than-20 d B.When the range of frequency band is between 8.6 to 9.83 GHz,the return loss of the circulator is no more than-20 d B.It shows the correctness of designing the circulator based on this YIG material and the practicability of low loss YIG material.