Interaction between large and small signals in a resonant transmission line based on magnetostatic waves

The influence of a large signal on the characteristics of a small signal near the frequency of the former is experimentally studied for the case of their simultaneous propagation through a resonant transmission line based on backward volume magnetostatic waves. The effects observed are caused by the excitation of spin waves in a ferromagnetic film at different large-signal frequencies and by the back influence of excited spin-wave packets on the amplitude and phase characteristics of the small signal.     

Characteristics of microwave magneto-optic modulation based on magnetostatic waves

According to the magneto-optic (MO) perturbation theory, the coupled-mode equations for guided optical waves (GOWs) with microwave magneto-static waves (MSWs) in MO film waveguides are presented, which cannot only be used to analyze the MO modulation induced by MSW pulses, but also explain the optical pulse compression caused by chirped MSWs. The rectangular pulse modulation of continuous guided optical waves by magnetostatic forward volume waves (MSFVWs) excited under normal bias magnetic field is theoretically studied in detail. It is shown that: (1) the diffracted light pulse approximates to an isosceles trapezoid, which is in agreement with the experimental results, and the duration time and the flat-top response time are equal to the sum and difference between the width and transit time of the rectangular MSFVW pulse, respectively; (2) utilizing a small duty factor of MSFVW pulse helps to improve the modulating data rate, which is in inverse proportion to the transit time, and the relative peak intensity of the diffracted light pulse is less than the corresponding Bragg diffraction efficiency when the MSW duty factor is less than 0.5.     

Wideband chaotic oscillation in a self-oscillatory system with a nonlinear transmission line on magnetostatic waves

Wideband chaotic microwave oscillation in a ring self-oscillatory system is studied. The system includes a solid-state power amplifier and a wideband nonlinear transmission line with a ferromagnetic film in which magnetostatic waves of different types are excited. It is found that the eigenmodes of the self-oscillatory system excited in the passband of the transmission line on magnetostatic waves become noisy because of spin wave parametric excitation due to the magnetostatic wave and nonlinearity of the power amplifier. A continuous spectrum of modes observed in the wideband chaotic signal is associated with the presence of a descending portion in the dynamic characteristic of the nonlinear transmission line, which arises when a magnetostatic surface wave is excited.     

Interaction of magnetostatic waves with current carriers in stratified structures

The interaction of magnetostatic waves with charge carriers in ferrite-semiconductor and ferrite-electron flux structures is reviewed. The basic equations needed to calculate the interaction effects in these structures are provided. Attention is turned to the possibility of amplifying fast magnetostatic waves in bodies of revolution by means of circular electron drift over the body surface. The possibility is discussed of amplifying magnetostatic waves in a ferrite film by an electron flux band. The interaction of magnetoelastic waves with electrons in ferrite-semiconductor structures is considered. A method of calculating the static EMF (electromotive force), induced by traveling MSW (magnetostatic waves) in a ferrite-semiconductor structure, is discussed. Attention is turned to circular currents, flowing in the semiconductor, which can vary substantially the longitudinal EMF and lead to generation of a transverse EMF in the structure. We discuss experimental studies on detection of interaction of magnetostatic waves with charge carriers, suggesting the possibility of wave amplification in ferrite-semiconductor and ferrite-electron flux structures, and exploring EMF induction mechanisms in the regime of traveling waves and ferromagnetic resonance.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 5–29, January, 1989.     

Phase conjugation of linear signals and solitons of magnetostatic waves

Phase conjugation of magnetostatic waves by a local longitudinal pump in yttrium iron garnet films is observed experimentally. Theoretical expressions are obtained which describe the experimental curves well.     

Impedance of the microstrip line for magnetostatic backward volume waves

We study excitation of magnetostatic backward volume waves on the microstrip line. The relation between the current density in the line and the normal component of the magnetic induction is found. The impedance of the line per unit length, i.e., its reactance and radiation resistance per unit length, is represented as a functional of the current density. The dependence of the operating-wave radiation resistance on the transverse size of the line and the width of the dielectric gap is studied. The radiation resistances of multistrip array and meander-type converters of magnetostatic backward volume waves are calculated     

基于微波段电子自旋共振测量电磁波的传播速度

当电子自旋共振发生在微波段时,根据微波段电子自旋共振条件,并使用电子顺磁共振谱仪和微波元件(波导管、谐振腔、短路活塞、环行器)等实验仪器测量出微波的波导波长,可以计算出真空中微波的波长.利用特斯拉计测量出共振时的磁感应强度,从而计算出了电磁波的传播速度.     

Experimental study of solitary waves in a nonlinear transmission line

Several properties of solitary waves were measured on a nonlinear transmission line. These include the transition from a linear dispersive response into a solitary wave response as the amplitude of a narrow voltage impulse is increased, and an observation of the recurrence phenomena of solitary waves. Supported in part by the National Science Foundation.     

信号传输线趋肤效应的分析

信号传输线的趋肤效应直接影响传输性能.通常引用半无限大导体对入射电磁波的衰减规律来定性说明传输线上的趋肤效应.本文则根据麦克斯韦方程组对导线内的电流分布进行分析,得出了导线内电流存在趋肤效应的结论,并推导了孤立圆导线单位长度的电阻计算公式.     

Indicatrices of magnetostatic surface waves

Indicatrices (isofrequency curves) of magnetostatic surface waves are studied with allowance for wave attenuation. A bias magnetic field is applied tangentially to a ferrite film. Arbitrary angles between the bias magnetic field and the wave vector are examined.     

Nonreciprocity engineering in magnetostatic spin waves

Magnetostatic surface spin waves (MSSW) excited from a coplanar waveguide antenna travel in different directions with different amplitudes. This effect, called nonreciprocity of MSSW, has been investigated by micromagnetic simulations. The ratio of amplitude of two counter propagating spin waves, the nonreciprocity parameter κ, is obtained for different ferromagnetic materials, such as NiFe (Py), CoFeAl, yttrium iron garnet (YIG), and GaMnAs. A device schematic has been proposed in which κ can be tuned to a large value by varying simple geometrical parameters of the device.     

Nonlinear surface magnetostatic waves in a ferrite semiconductor structure

A theoretical analysis is made of the propagation of a nonlinear surface magnetostatic wave in a planar ferrite semiconductor structure as a function of the carrier concentration in the semiconductor layer. It is shown that for certain concentrations the surface magnetostatic wave is unstable with respect to longitudinal perturbations and may propagate perpendicular to the magnetic field in the form of solitons. Zh. Tekh. Fiz. 69, 119–121 (June 1999)     

Compression of a microwave pulse using a multi-mirror resonance delay line

We develop the theory of compression of a frequency-modulated pulse in a ring-shaped multi-mirror delay line connected with the input and output quasioptical waveguides by means of a common corrugated mirror. An efficiency of about 60% is obtained in an experimental compressor having a resonant frequency of 34 GHz for the fourfold compression of a pulse with an initial duration of 11 ns. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 4, pp. 314–319, April 2008.