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Rigorous magnetodynamic (MD) study presented in this paper reveals what seems to be the real nature of ferromagnetic resonances occurring in gyromagnetic samples situated in larger resonant cavities. Experiments were performed with cylindrical and spherical YIG samples inserted into either cylindrical dielectric resonator or typical rectangular cavity. It is shown that the dominant mode present in the YIG sample, which was identified as the $\text {HE}_{111}^{+}$ mode, satisfies the magnetic plasmon resonance condition defined by the effective permeability ${\mu }_{r}\approx {-1}$ for cylindrical samples or ${\mu }_{r}\approx {-2}$ for spherical samples. Experiments confirmed the existence of surface resonances, identified as magnetic plasmons, and volume resonances. Comparison between the MD model, the quasi-magnetostatic model, and the perturbation theory was performed and limitations of the approximate approaches are shown.

A calculation model has been developed to describe the propagation of magnetostatic waves in a periodic structure consisting of two one-dimensional magnonic crystals, the periods of which are shifted relative to each other in the wave propagation direction. It is shown that, depending on the shift between the magnonic crystals, up to three bandgaps can be formed in this structure in the first Bragg resonance.

A periodic structure in the form of two coupled magnonic crystals in which the coupling allows effective control of nonlinear effects during propagation of magnetostatic waves is examined. The main specific features of the nonlinear effects are revealed in comparison with the periodic structure in the form of one magnonic crystal. The ability of the nonlinear coupler to suppress high- or lower-power signals for the functional processing of microwave-frequency signals is demonstrated.

We theoretically demonstrate how cloaks, anticloaks, magnifiers and illusion devices can be devised for the case of static magnetic fields. For some of these devices, we make use of the concept of negative permeability materials. Because these materials can be emulated in practice by sets of currents, our results may provide the recipe for the experimental realization of novel devices for controlling magnetic fields.

The review of magnetodynamic resonances in ferrite resonators and their mm-wave band applications was given. Ferrite resonator eigenexcitations classification has been presented. The analytical theory for modes resonant frequencies calculations is stated and a number of prototype electronically tunable mm-wave devices, utilizing the “above” and “below FMR” magnetodynamic resonances, including isolator, phase shifter, band-pass and band-stop filters have been demonstrated.

Brillouin light spectroscopy method of magnetic materials was used for experimental study of multimode propagation characteristics of surface magnetostatic waves in an irregular ferrite waveguide. It was experimentally demonstrated that the spatial transformation of modes is possible in tapered ferrite planar waveguide due to breaking of the axis symmetry.

An irregular tapered ferrite waveguide with a periodically width-modulated region was investigated. By using space- and time-resolved Brillouin light scattering spectroscopy, we measured the features of the intermodal interaction of width modes and their scattering at the boundaries of the waveguide. Near the band-gap frequency region, the spatial pattern of the spin-waves depends on the mode interaction in the periodically width-modulated yttrium-iron-garnet waveguide. These experimental results are important for controlling spin-wave propagation in width-modulated magnetic structures for future spintronic devices.

A technique for the experimental visualization of the distribution of the amplitudes and phases of the magnetostatic waves propagating in ferrite-film structures is developed. It is shown that applying the Fourier transform to the data obtained with the use of this technique, it is possible to investigate the mode composition of the magnetostatic waves and find dispersion dependences for each mode. On the basis of the proposed technique, distributions of magnetostatic surface waves in bilateral samples of ferrite films are investigated. It is found that, at a wavelength comparable with the substrate thickness, the ferrite film at the opposite side of the substrate significantly changes the wave distribution in the sample and causes spatial beating along the propagation axis.

Propagation of magnetostatic waves in a tangentially magnetized ferrite plate with a normal uniaxial anisotropy under the conditions for the orientational phase transition of the second order is considered. Dispersion relations for quasi-surface and quasi-volume magnetostatic waves with the wave vector arbitrarily oriented in the plane of the plate have been obtained. The limiting frequencies of the regions of existence of both modes have been determined and the dependences of these frequencies on the anisotropy field and wave-vector orientation have been investigated.

Propagation equation of magnetostatic waves in an arbitrarily magnetized yttrium-iron-garnet/gadolinium-gallium-garnet waveguide coated with perfect metal planes is obtained using the method of the surface magnetic permeability. And ground effects on magnetooptic Bragg cells are investigated with the magnetooptic coupled-mode theory. Theoretical analysis indicates that, diffraction efficiency of guided optical waves can be improved by adjusting the spacing of the metal plane from the ferrite film, and ground effects on the diffraction efficiency will be enhanced using an appropriately tilted bias magnetic field. In the metal clad waveguide system, the magnetostatic wave frequency at which the diffraction efficiency peak is obtained corresponds to the “zero-dispersion” point. Performance of RF spectrum analyzers in this system can also be improved by comparing with the case of the sandwich waveguide. Therefore, magnetooptic Bragg cells with the metal clad waveguide are potential applications to the microwave communication and optical signal processing.

Scattering of the magnetostatic surface waves generated in thin films by the gratings formed from slots in a metal screen is theoretically analyzed. A boundary-value problem for the Maxwell equations is formulated and solved in the static approximation. An algorithm of numerical solution of the boundary-value problem is proposed. Scattering of magnetostatic surface waves by 2D periodic slot gratings that are infinite along one coordinate and finite along the other coordinate is studied for an arbitrary orientation of slots and an arbitrary angle of incidence of the magnetostatic wave. The band structure of gratings is studied. The possibility of formation of magnonic crystals based on slot gratings is demonstrated.

A dispersion relation is derived for magnetostatic waves in a ferrite film with inhomogeneous layers near the interfaces. It is shown that the transition layers can be taken into account using a single integrated parameter, namely, the effective film thickness. It is established that the layered structure of the film causes an extra wave damping. The relations obtained can be used to analyze the dispersion and damping of the main modes of magnetostatic waves.

Microwave chiral fields originated from a small ferrite-disk resonator with magnetostatic oscillations can form far-field radiation pattern with a strong and controllable squint. Such an effect of a spatial mode division by a single radiation element is unique. It is very attractive for development of novel microwave antennas with controllable far-field phase structure distributions.

Effects of a metamaterial slab with negative permeability applied to a magnetically coupled two-loop wireless power transfer system on efficiencies are analyzed. Particularly, the maximum efficiencies are examined as a function of s/d (s: slab width, d: distance between two loops) and the slab loss tangent. They are evaluated in terms of coupling coefficients (k), effective Q-factors of the loop, and optimum loads for maximum efficiencies, considering the slab losses. Using the meta-slab, some enhance-ment of transfer efficiencies can be achieved when s/d ≈0.2 even for the case of considerable loss tangent of 0.2.

A new class of electric field tunable ferrite-piezoelectric microwave devices has been designed and characterized. The devices are based on ferromagnetic resonance or magnetostatic waves excitation...

Interaction between forward bulk magnetostatic waves propagating in a structure consisting of two planar films separated by a nonmagnetic spacer is studied. When two modes are excited in the structure, a phase mismatch between them produces symmetric, asymmetric, and “forked” beats of the amplitudes of the magnetically coupled modes. It is shown that the parameters of the beats can be controlled by varying the magnetic field intensity and ration between the initial amplitudes of the modes excited in the structure.

The effect of dispersion on the propagation of linear rectangular pulses of magnetostatic waves in YIG films is studied. With surface magnetostatic waves propagating in YIG filins and composite ferrite-insulator-metal structures. it is demonstrated that, for the near-rectangular phase-unmodulated input pulse and the distance between input and output transducers equal roughly to half the dispersion length of' the pulse, the FWHM of the output pulses is 50-60% of the initial value. This fact can be used for estimating the dispersion coefficient of magnetostatic waves.

The dispersion relation for magnetostatic surface waves in a ferrite/dielectric/metal-strip-grating structure is obtained. It is shown that dispersion of magnetostatic surface waves must be qualitatively the same as in a ferrite/dielectric/metal structure, while the slope of the dispersion curve in the region of backward magnetostatic waves existing in a ferrite/dielectric/grating structure (and in a ferrite/grating structure in particular) is considerably higher than the slope of this curve corresponding to a ferrite/dielectric/metal structure. It is found that this phenomenon can be explained by the dependence of the grating’s shielding capability on the wave number of magnetostatic surface waves. A grating shielding parameter is introduced and dependences of this parameter on the wave number that can be used to explain the phenomena observed in the experiment are determined.

Spatiotemporal dynamics of the multimodal propagation of magnetostatic waves in a transversally confined ferrite waveguide and the parametric excitation of spin wave under conditions of three-magnon decay processes are experimentally investigated by the Brillouin spectroscopy.

The noncollinear interaction of guided optical waves with magnetostatic waves under inclined bias magnetic field is theoretically studied in detail. Similar approach can also be applied to the collinear interaction. Calculation results indicate that the diffraction efficiency (DE) in magnitude is equal to the mode-conversion efficiency (MCE) under vertical bias magnetic field, but they differ greatly under inclined bias magnetic field. By comparison to the case of vertical magnetization, the DE or the MCE can be greatly increased under inclined magnetic field. The characteristic of the DE curves obtained is basically in agreement with the experimental result.

The noncollinear interaction between guided optical waves and magnetostatic waves under inclined bias magnetic field is studied in detail. The diffraction efficiency (DE) and the mode-conversion efficiency (MCE) of guided optical waves with magnetostatic forward volume waves in the bismuth-doped yttrium–iron–garnet (Bi-doped YIG) waveguide are calculated numerically. The calculation results indicate that the DE and the MCE are different in physical conception and the DE is not equal to the MCE in magnitude under inclined bias magnetic field. The DE may be greatly increased by using an appropriately inclined bias magnetic field, which has been experimentally confirmed in a pure YIG waveguide. By using an inclined bias magnetic field and the Bi-doped YIG waveguide, under the phase-matching conditions, the maximum DE can come up to 79.5% or more.

The mode-conversion efficiency (MCE) of guided optical waves with magnetostatic waves (MSWs) generated in inclined magnetized Bi-doped YIG film is calculated at the first time. Calculation indicates that the MCE can distinctly be improved under inclined bias magnetic field. The dependence of MCE on the inclined angle θ is nonreciprocal. When the directions of MSW propagation and magnetic field (| θ | keeps fixed) are changed at the same time, the MCE does not almost vary.

The directivity diagram of electromagnetic waves, generated during the propagation of backward bulk magnetostatic waves (BMSWs) in a ferrite plate tangentially magnetized by a decreasing field has been calculated using a model of the accelerated motion of magnetic charges. It is shown that the directivity diagram consists of two lobes, which are symmetric with respect to the ferrite plate surface and tilted back relative to the direction of backward BMSW propagation.

Expressions for the temperature coefficients of frequency for magnetostatic waves in tangentially magnetized ferrite films having cubic anisotropy are obtained and analyzed. It is shown that in cases where the cubic axis lies in the plane of the film, temperature-induced changes in both the magnitude and direction of the external field can be used for thermostabilization of the frequencies. The problem of two-frequency thermostabilization is considered. The results of experimental investigations of the temperature characteristics of magnetization waves in a tangentially magnetized film of yttrium iron garnet with a {100} surface are presented.

An analytical solution is obtained for the self-consistent problem of the excitation of beams of magnetostatic waves by a converter of arbitrary type. Radiation patterns are calculated numerically for stripline converters at the frequencies where magnetostatic surface waves exist.

The problem of reflection of backward volume magnetostatic waves (BVMSWs) from a metallized portion of a ferrite film has been solved rigorously in the magnetostatic approximation. The condition of total internal reflection is formulated. This effect can be used for creation of a waveguide of BVMSWs. The waveguide is a slot in the metallic coating of a ferrite film with the slot's edges parallel to a magnetizing field. The use of such a waveguide makes it possible to avoid diffraction losses which accompany propagation of BVMSW beams in real devices. The BVMSW waveguide is convenient for connection with an active element (for example, with a Gunn diode). A simple method of calculating the dispersion characteristic of such a waveguide has been suggested. This characteristic is determined experimentally for some waveguides. The theoretical results and the experimental data are in reasonable agreement.

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.

Effects of the resonant Bragg scattering of magnetostatic backward volume waves on the periodic structure of a conductive meander pattern with an alternating current are analyzed theoretically and compared with experiment. It is shown that unlike a static grating, a dynamic grating causes a frequency shift of the scattered wave. It is proposed that this phenomenon be utilized for effective control of the intermodal conversion of magnetostatic waves.

Quasisurface magnetostatic waves propagating in a ferrite film along two magnetized channels are simulated numerically. It is shown that the interaction between the channels is manifested differently, depending on the wavelength. In the long-wavelength region the interaction between the channels has a distributed character; in the short-wavelength region the interaction between the channels appears as if it takes place at their boundary. The magnetized region of the ferrite film between the channels behaves both as a conductor of the alternating field and as a medium with eigenmodes, so that under certain conditions the waveguide can be transformed into a three-channel structure. The dispersion curves of the magnetostatic wave modes of a two-channel waveguide lie in zones bounded by the dispersion curves of the corresponding modes of a one-channel waveguide of double width. As the gap between the channels increases, the dispersion curves of the odd modes shift toward shorter wavelengths, and those of the even modes shift toward longer wavelengths.

A new approach to the design of a nondispersive delay line on magnetostatic waves is proposed, whereby the cascades operating on the surface waves and the backward volume waves have a common passband in the same magnetic system due to a difference in the crystallogrphic orientations of ferrite waveguides cut from a {100} yttrium iron garnet film. The possibility to obtain a pulse delay time of up to 113 ± 3 ns in a 300-MHz-wide frequency band is experimentally demonstrated. The central frequency of this band can be tuned within 4–6 GHz by changing the applied magnetic field.

The propagation of surface and volume magnetostatic waves in unsaturated films of yttrium iron garnet is studied experimentally for the case when the wavelength greatly exceeds the domain width, while the domain width is comparable to the film thickness. The characteristics of these waves are examined for symmetric linear, asymmetric linear, and symmetric zigzag strip domain structures in the films. These characteristics cannot be explained by a theory based on averaging the magnetization over all the domains.

Dispersion and attenuation of non-linear surface magnetostatic waves (MSSW) propagating in thin yttrium-irongamet (YIG) ferrite films have been studied both experimentally and theoretically. They were defined from the amplitude and phase alterations of the wave as it traveled along the "non-equilibrium" part of the film. At the border of such a non-equilibrium part the wave power is equal to the threshold value. The value for the threshold power is defined by the first- and second-order parametric decay processes for the MSSW.

This work presents the design, technology and experiment on a frequency tunable narrow-band filter based on coupled straight edge resonators (SERs). A number of series configurations of cascaded resonators have been obtained by properly masking a yttrium iron garnet (YIG) magnetic film, and by using a wet chemical etching technique in hot phosphoric acid to get the coupled SERs directly onto the gadolinium gallium garnet (GGG) substrate used for the epitaxial growth. Ferromagnetic resonance (FMR) measurements of the coupled SERs are done. Theoretical design and circuit simulation are also presented.

The dispersional properties of a surface magnetostatic wave (MSW) in a laminar structure consisting of ferrite film and a high-temperature superconducting (HTSC) layer are studied in detail. The propagation of surface MSW in this structure is investigated, and the dispersional equation is obtained; the granular character of the HTSC films and the influence of constant magnetic field are taken into account here. The magnetic field is responsible for breakdown of the Josephson layer of granular HTSC films and the appearance of nonsuperconducting layers close to the film surface. It follows from the calculation results that, when the HTSC film passes to the superconducting state, the dispersional characteristics of the MSW undergo a discontinuity. The magnitude of the discontinuity depends on the film thickness, the critical current, and the granule size. The results obtained may be used in designing various microelectronic devices based on granular HTSC films.

A number of significant advances have been made recently in the MSW-based integrated magnetooptics. Resulting new class of optical devices called MO Bragg cell modulators which are capable of providing desirable features similar to that of the now prevalent AO Bragg cell modulators, but with potentially superior performance characteristics, have been realized. These advances have paved the way for realization of a variety of MSW-based integrated MO device modules, such as high-speed optical scanners and space switches, electronically tunable carrier frequency band RF spectrum analyzers and correlators, and optical frequency shifters and modulators with applications to RF signal processing and communications.

In this paper, the second-order and fourth-order relativistic chromatic variational functions for all kinds of relativistic chromatic aberrations of a combined electrostatic-magnetostatic focusing-deflection system have been derived in detail. Here, the relativistic chromatic aberrations produced by the variations of accelerating voltage, currents of magnetostatic round lenses, voltages of electrostatic round lenses and excitations of deflector multipoles are considered.

This paper reports results of theoretical studies of magnetostatic surface wave (MSSW) propagation in a photosensitive semiconductor-ferrite layer structure while the external electromagnetic wave acts on the semiconductor surface. The photoelectromagnetic effect is included in the theory. The dispersion relation of MSSW has been found and the effects of various intensities of the electromagnetic wave on the propagation characteristics have been examined. Values for CdSe and yttrium iron garnet parameters were used for computer simulation. It has been shown that the MSSW propagation loss increases, the frequency range in which the MSSW exist narrows and the group time delay decreases by a factor of 3–4 with increasing the intensity of the external wave.

The layered structure that includes magnetized ferrite film, dielectric and metal shield with the slit is considered. The components of magnetic field which is excited when the magnetostatic waves diffracts by a slit in the case of tangentially and normally magnetized ferrite film is defined.

Backward Wave Oscillators are the most established vacuum electronic devices for THz and near-THz applications. The most powerful of these VEDs are BWO-clinotrons. Design process of 400 GHz Clinotron and its magnetic focusing system using 3D and 2D electromagnetic computer codes is presented. The comparison of simulation results with ones obtained experimentally has been presented. An output power of 43 mW is demonstrated at 387 GHz.

International audience; The miniaturization of devices and the increase of operating frequencies are two important issues for communication system development. This requires a high degree of integration, higher performance and lower cost. Isolator is an important non-reciprocal passive component for source protection. In most cases, the non-reciprocal effect is based on field displacement phenomenon induced by a magnetized ferrite material. In this paper we propose a new design of a coplanar isolator based on field displacement, composed of a non-symmetrical coplanar transmission line, made from a ferrite layer and ground plane below. Simulations were performed using HFSS software. Measurements were made on a first 1000 μm-thick YIG film sample giving 1 dB of insertion losses and 17 dB isolation and on a second sample made from a 150 μm-thick YIG ferrite sample giving an insertion loss lower than 2 dB. Interesting applications of this isolator structure are considered.

Formation and propagation of envelope solitons of dipolar spin waves under the action of nonstationary parametric pumping and dynamics of phase-conjugated signals created in the process of soliton interaction with pumping have been investigated. The influence of parametric pumping on the threshold of soliton formation was shown to be critically dependent on the moment of application of the pumping pulse. The qualitatively different behavior of phase-conjugated pulses created by linear and nonlinear (solitonic) incident signals was discovered. The possibility of soliton formation in phase-conjugated wave was considered.

Methods of calculating the characteristics of the three main types of magnetostatic waves (MSWs) in ferrite films with inhomogeneities along the propagation direction are suggested. It shown that the use of non-uniform magnetic fields is when it is necessary to provide increased wave absorption or to increase their delay times under the condition of the absence of significant reflections. Nevertheless, there may be real situations in which in MSW devices the losses due to dissipation and reflection can be of the same order, which require the latter ones to be taken into account.

The influence of cubic and uniaxial anisotropy on magnetostatic waves is investigated both theoretically and experimentally. The experimental results for standing and propagating magnetostatic waves in (111)-oriented thin garnet films are in good agreement with theoretical predictions. On the basis of our investigations we propose a curve-fitting method for estimating of the anisotropy constants.

Recent advances in Beam Optics Analyzer (BOA) are reported to demonstrate its features and capabilities. BOA is a finite element particle-in-cell code with adaptive meshing. Its usage and detailed results for several electron gun simulations with optimization will be presented.

Amplitude-frequency characteristics of a device on the basis of magnetostatic waves were experimentally investigated in the frequency band 2–8 GHz and at the levels of input signal power 0.06mW–600mW. The undoped YIG film with saturation induction 1750G was applied in the device. The orientation of external magnetic field was at the plane transversal to the direction of propagation of magnetostatic waves. For different frequency bands the existence of optimum angles of magnetic biasing at which losses of the device were minimal was proved. So at input signal power of 600mW, frequency tuning in the band 1.9 GHz–2.3 GHZ with the angle of magnetic biasing 8° and in the band from 2.35 GHz up to 2.85 GHZ for the angle 12° the insertion losses of the device did not exceed 6.5 Db. It was shown, that achievement of rather small insertion losses at frequencies lower than 3.27 GHz became possible due to providing conditions of wave generation and propagation of nonreciprocal magnetostatic volume.

The propagation of magnetostatic waves at the interface between an yttrium-iron-garnet (YIG) film and a layer of perovskite compound LaAlO3, SrTiO3, or YBa2Cu3O7−x (YBCO) was experimentally studied. The microwave dispersion characteristics were measured at room temperature and at 77 K. An effective method for controlling the propagation speed and the phaseshift of magnetostatic waves in the YIG/YBCO structures is suggested. Specifically, the phaseshift at 3 GHz is changed by more than 1.5π by reducing the critical current density from 1 to 0.7× 106 A/cm2.

Calculations are made of the trajectories of return surface magnetostatic waves (SMSWs) in a ferrite-dielectric-metal structure magnetized by a nonuniform “ridge” field. It is shown that there are four different types of trajectories. Conditions are determined for which the return SMSWs propagate in the direction opposite to the forward SMSWs and in the same direction as the forward SMSWs.

A dispersion law is obtained and analyzed for the first time for magnetostatic waves in a tangentially magnetized ferrite wafer with uniaxial anisotropy where the axis is perpendicular to the plane of the wafer and the applied static magnetic field is weaker than the anisotropy field. This model qualitatively describes the dispersion of magnetostatic waves in hexa-and orthoferrite wafers and also in an unsaturated ferrite wafer.