The dispersion characteristics of shielded microstrip lines on magnetized ferrite and anisotropic dielectric substrates

The dispersion characteristics of the dominant mode in shielded microstrip lines on magnetized ferrite and anisotropic dielectric substrates have been obtained. The solution is obtained by applying the transverse equivalent transmission line in the spectral domain and Galerkin's method. Numerical results for the frequency-dependent propagation constants are presented which could be used in designing directional couplers and isolators.     

Suspended stripline on magnetized ferrite and anisotropic dielectric substrates

Suspended stripline on magnetized ferrite and anisotropic dielectric substrates are examined here. The spectral domain immittance approach was used for obtaining the dyadic Green's functions in the Fourier transform domain. Galerkin's method was used to obtain the dispersion characteristics of the dominant mode, and the curves for a few cases are shown as examples which could be used in designing isolators, phase shifters, and directional couplers.     

Transient analysis of microstrip lines with ferrite substrate by extended FD-TD method

In this paper, the wide band transient signal propagation characteristics along microstrip lines with ferrite substrate are presented. In the analysis how the frequency dependent media such as ferrite may be genearally fomulated by FD-TD method is described. the distortions of transient signal in Gaussian shape propagating along uniform or step junction microstrip are simulated by the extended FD-TD method. Results show the distinctive influence of applied DC magnetic field and magnetizaton on the dispersion of transient signal.     

The nonlinear study of microstrip lines containing ferrite dielectric layers

In this paper, the transient responses of microstrip containing ferrite dielectric layers are studied by using extended FD-TD method. When the microwave signal propagating along the microstrip is comparable with the applied DC magnetic field on the ferrite, the nonlinearity of ferrite medium is represented. The propagating procedure of Gaussian pulse in the microstrip are simulated. It is shown that the effects of the pulse amplitude on the transmission distortion of Gaussian pulse is pronounced.     

磁化铁氧体电磁散射的移位算子FDTD分析

将移位算子（shift operator,SO）-时域有限差分（fintie difference time domain,FDTD）方法推广到外磁场沿任意方向时磁化铁氧体的情形.从磁化铁氧体的相对磁导系数张量和各向异性情形下Maxwell旋度方程出发,推导出外磁场沿任意方向情形下磁化铁氧体电磁散射的SO-FDTD迭代公式.应用该方法计算了磁化铁氧体层、磁化铁氧体球及含磁化铁氧体涂层的Von Karman形雷达罩电磁散射,数值计算结果表明了该算法的正确有效性. 关键词： 磁化铁氧体 FDTD 移位算子法     

Fuul-wave analysis for coupling characteristics of multiconductor microstrip lines on semiconductor substrate

Conclusion The coupling effects for multiconductor microstrip on semiconductor substrate are analyzed by full-wave spectral domain approach. It is believed that the contribution aforementioned will facilitate successful design of MMIC modules in millimeter wave band and very high-speed digital integrated circuits.     

基于Newmark算法的任意磁化方向铁氧体电磁散射时域有限差分分析

利用坐标系转换矩阵给出实验室坐标系中饱和磁化铁氧体的频域磁导系数张量,再通过频域到时域的转换关系jω→?/?t得到一个二阶微分方程形式的时域本构关系.然后采用Newmark方法求解时域本构关系从而给出一种适用于处理任意磁化方向铁氧体电磁问题的Newmark时域有限差分算法.利用此算法计算了饱和磁化铁氧体层的反(透)射系数和饱和磁化铁氧体球的后向雷达散射截面,所获得的结果验证了此算法的正确有效性.     

High-frequency micro-inductor fabricated on NiCuZn ferrite substrates

We have fabricated the planar micro-inductors directly on a NiCuZn ferrite substrate. Due to NiCuZn's high resistivity, no insulator is required between the coil and the magnetic film; an advantage in terms of ease fabricated and stray capacitance reduction. Sandwiched inductors show improvement of inductance from 16 to 80 nH at 1 MHz compared with the coreless inductors, and the increment of inductance is larger than the sandwiched thin film inductor.     

Time-domain analysis of lossy coupled transmission lines

A new approach, based on the waveform relaxation technique and fast Walsh transform, is first presented for the analysis of lossy coupled transmission lines (LCTL) with arbitrary terminal networks. The simulation accuracy of the new method can be greatly improved, the disadvantage which always exists in previous methods [1]–[7] can be avoided and a considerable saving in time and memory of CPU is obtained.     

X波段叠层片式微带铁氧体环行器的设计

采用叠层片式化设计有望实现微波环形器与低温共烧陶瓷(LTCC)技术的结合。借助三维电磁仿真手段设计了一种X波段微带铁氧体环行器,基片采用具有不同饱和磁化强度的旋磁材料构成叠层片式结构。研究结果表明,叠片数目及其饱和磁化强度的搭配对环形器的回波损耗和隔离度特性影响显著,这与叠层结构引入的界面及叠片变化的饱和磁化强度影响了环形器的等效输入电路参数有关。通过优化设计,可以获得具有高回波损耗、高隔离度及低插入损耗等优良性能的器件,但带宽受叠片数目及其饱和磁化强度的搭配影响较小,难以通过优化进行拓展。     

Spectral domain analysis of dispersion management without averaging

It is shown how a straightforward regular perturbative analysis can be used to derive an integral equation for the spectral shape of a dispersion-managed soliton that takes fiber loss and amplification into account without resorting to averaging. Using functional analysis, one can then find an accurate approximate Gaussian solution that should prove useful for the design of a dispersion-managed transmission link.     

Analysis of double-layered nonradiative dielectric waveguide containing a magnetized ferrite

The propagation characteristics of the dominant mode in magnetized-ferrite-loaded double-layered nonradiative dielectric waveguide are studied. The analysis is based on mode-matching method. Numerical results are presented for various values of structure and material parameters.     

Scattering characteristics of conducting cylinder coated with nonuniform magnetized ferrite

An analytical technique, referred to as the scattering matrix method （SMM）, is developed to analyse the scattering of a planar wave from a conductolution for the nonuniform fering cylinder coated with nonuniform magnetized ferrite. The SMM srite coating can be reduced to the expressions for the scattering and penetrated coefficients in four particular cases： nonuniform magnetized ferrite cylinder, uniform magnetized ferrite-coated conducting cylinder, uniform ferrite cylinder as well as homogeneous dielectric-coated conducting cylinder. The resonant condition for the nonuniform ferrite coating is obtained. The distinctive differences in scattering between the nonuniform ferrite coating and the nonuniform dielectric coating are demonstrated. The effects of applied magnetic fields and wave frequencies on the scattering characteristics for two types of the linear profiles are revealed.     

Drift of vertical Bloch lines in a domain wall with a noninterchangeable spectrum in perpendicularly magnetized films

The dynamics of vertical Bloch lines in variable external magnetic fields is examined with allowance for the magnetostatic noninterchangeability of the spectrum of the domain wall. The drift velocity of the translational motion of vertical Bloch lines is calculated and is found to be nonzero in second order in the weak oscillating field. Zh. éksp. Teor. Fiz. 112, 2169–2177 (December 1997)     

Em wave diffraction by a finite set of magnetized ferrite cylinders

The paper presents a rigorous solution of the diffraction problem by a finite set of magnetized ferrite cylinders. The main purpose of the research is to determine the steerability of scattering diagram of diffraction by several longitudinally magnetized ferrite cylinders. A plane wave scattering as well as main mode scattering by cylinders in the open end of rectangular waveguide are considered and numerical investigations are presented.     

Wave diffraction by a finite set of azimuthally magnetized ferrite cylinders

The article is devoted to the problem of scattering of plane linear and circular electromagnetic waves by a set of ferrite-coated cylinders. Particular attention is paid to the possibility of controlling the scattering pattern by the azimuthal magnetic field induced in the ferrite by the dc current in metal core of cylinders. It is shown that the best sensitivity can be obtained for the magnetic field, which provides the magnetic resonance inside ferrite layer. Relevant scattering patterns are also presented.