Abstract: A method of magnetostrictive (MS) guided wave testing of a ferromagnetic structure. One or more MS transmitters, each configured as a patch of ferromagnetic material, are acoustically coupled to the structure. Each MS transmitter is magnetized to produce a bias magnetic field in the patch. One or more MS receivers are acoustically coupled to the structure in a location remote from the MS transmitter(s). An alternating current (AC) is applied to the structure, thereby producing time-varying magnetic fields and MS vibrations in the MS transmitter(s) resulting in guided waves in the structure. MS response signals are received at the MS receiver(s), indicating whether the structure has any anomalies.

Abstract: A microwave bandstop filter having a magnetic strip formed over dielectric material. The magnetic resonant frequency is controlled by an induced magnetic anisotropy in the magnetic strip of the microwave bandstop filter. The magnetic anisotropy field is induced by an anisotropic surface texture formed on the surface of the magnetic strip itself, or formed on an underlying layer. Alternatively, the anisotropic surface texture could be formed on both an underlying layer and on the magnetic strip itself. This induced magnetic anisotropy field allows the resonant frequency of the microwave filter to be controlled over a wide frequency range and make high frequency operation possible without reliance on the application of an externally applied magnetic field.

Abstract: A lifecycle analyzer includes a temperature control element for controlling the temperature of a plurality of magnetoresistive (MR) elements, which may be, e.g., in bar, slider, head gimbal assembly, or head stack assembly form. The MR elements are in electrical contact with a stress probe element for applying a bias voltage or current stress. The MR elements and/or a magnetic field generator are moved to place one or more MR elements within the magnetic field of the magnetic field generator for testing. During testing, the MR elements are in electrical contact with a test probe element. The temperature of the MR elements may be controlled during both the stressing and testing.

Abstract: A magnetostrictive system is shown wherein there is included a wave guide but no return wire. The wave guide is folded and acts as the completed wire (whether solid or hollow) for conducting current for the current input pulse.

Abstract: A S/N enhancer using the magnetostatic wave signal.

Abstract: There is provided a magnetoresistance effect element which is capable of causing a large sense current to flow between electrodes and which has a smaller dispersion in direction of magnetization of a CPP element based on a magnetic field due to the sense current and has a lager reproducing output, and a method for producing the same. The magnetoresistance effect element is produced by: after forming a first electrode, forming a magnetoresistance effect film on the first electrode; applying a self-condensing organic resist on the magnetoresistance effect film, and thereafter, causing the organic resist to be droplets; subsequently, forming an insulating film thereon, and thereafter, removing the organic resist to form a groove portion in the insulating film to expose the top surface of the magnetoresistance effect film; and filling the groove portion with an electrode material to form a second electrode.

Abstract: Magnetostatic devices includes: input and output electrodes for including energy conversion pattern provided in a dielectric substrate; a multi-layer -magnetic substance structure placed at an upper portion of the dielectric substrate, wherein magnetically active thin film is placed at both sides of a magnetically inactive substrate; an upper shield, composed of grounded conductor, for preventing the input and output electrodes from coupling; a lower shield provided at the dielectric substrate, wherein the substrate contain a hole with the same length as the upper shield, and walls of said hole are provided with conductor; a magnetostatic wave end portion, inserted into the dielectric substrate to be placed at both end plane of the multi-layer magnetic structure, for blocking the magnetostatic wave not to reflect therefrom; and a magnetostatic wave reflector, provided in the dielectric substrate as a line whose width vary, for reflecting and selecting a desired pass band before it reaches to the magnetostatic

Abstract: A structure (and method) for tuning a resonant structure, includes a resonant structure including either a predetermined material coating provided on either a bar or a cantilever, or a lightly doped single crystal semiconductor material, and a circuit for providing a variable field adjacent the resonant structure, with the length or at least one of the elastic constants of the resonant structure changing with the application of the variable magnetic or electric field, respectively, thereby to selectively tune the resonant structure.

Abstract: In accordance with the invention, magnetostrictive saw devices are provided with improved transducer structures for enhanced performance. In one improved device, the transducers are in the form of gratings with interconnected ends for reduced resistance and inductance. In another embodiment, the transducers are shaped to provide apodization. In yet a third embodiment, transducer performance is enhanced by patterning composite structures.

Abstract: The present invention is a method for adjusting different resonant frequencies of a plurality of mechanical resonators formed on a common substrate, in a case where the resonant frequencies of the resonators are a function of each resonator thickness. According to this method the resonators are each formed with an etchable top electrode layer which includes a material having different etching properties as a topmost layer for each of the resonators having different resonant frequencies. By selectively etching these etchable layers one at a time in the presence of the others, one may adjust the resonant frequencies of each of the resonators without need to mask the resonators during the etching process. Associated with this method there is a resonator structure having a top electrode structure having a topmost layer having different etching characteristics for different resonators.

Abstract: A magnetostatic wave device includes a Gd3Ga5O12 substrate off-angled from a {110} plane. A magnetic thin film including a crystal of garnet is formed on the Gd3Ga5O12 substrate by liquid-phase epitaxy. A transducer operates for exciting magnetostatic wave in the magnetic thin film in response to an RF electric signal. A bias magnetic field is applied to the magnetic thin film. There is a relation as 20°≦|&thgr;1+&thgr;2|≦35°, where “&thgr;1” denotes an angle between a longitudinal direction of the transducer and a <001> orientation of the crystal in the magnetic thin film, and “&thgr;2” denotes an angle between a transverse direction of the transducer and a specified direction.

Abstract: A magnetostatic wave device comprises a magnetic garnet single crystal film. The single crystal film magnetic garnet is represented by the general formula of Y3Fe5-x-yInxMyO12 (wherein M is at least one of Ga, Al and Sc, 0.01≦x≦0.45 and 0≦y≦1.2) and the Curie temperature is about 150° C. to 285° C.

Abstract: An improved surface acoustic wave device includes a film of a magnetostrictive material disposed on a substrate and spaced apart input and output transducer elements disposed on the film. The input element causes horizontally polarized shear waves to propagate along the film via the magnetostriction of the film. The shear waves propagating along the film are received by the output transducer element. The SAW device can be integrated on a microelectronic circuit useable in single chip radio frequency applications.

Abstract: There is provided a magnetostatic wave device which operates even with a substitution R, A:YIG having a small film thickness and which has a wider operational frequency band. A magnetostatic wave device comprising a magnetic garnet film is provided which is made of a material expressed by a general formula: (Y.sub.1-r R.sub.r).sub.3 (Fe.sub.1-a A.sub.a).sub.5 O.sub.12 where R is at least one selected from among La, Bi, Gd and Lu; A is at least one selected from among Al, Ga, In and Sc; r and a are within the ranges 0.ltoreq.r.ltoreq.1 and 0.ltoreq.a<1, respectively; and r and a can not be zero at the same time. Further, the crystal structure of said magnetic garnet film is a superlattice.

Abstract: In accordance with the invention, the operating frequency of a SAW device is magnetically tuned. In a first embodiment, the SAW device comprises a piezoelectric layer mechanically coupled to a substrate or body of magnetostrictive material. Strains magnetically induced in the magnetostrictive substrate is coupled to the piezoelectric layer, altering the velocity at which it can transmit acoustic waves. In an alternative embodiment, surface waves are directly generated in a magnetostrictive material and the velocity is directly altered by an applied magnetic field.

Abstract: Proposed is an improvement in a magnetostatic surface wave device such as an S/N enhancer comprising a thin film chip of a magnetic oxide garnet, e.g., gallium-substituted YIG epitaxially grown on the surface of a substrate, e.g., GGG, to which a magnetic field is applied within the plane of the thin film. The low-pass cut-off frequency of the microwaves can be decreased to 400 MHz or lower and the half-value width of magnetic resonance .DELTA.H can be small enough when the principal plane of the thin film of the magnetic oxide garnet is the (110) plane and the magnetic field applied thereto is in such a direction that the angle between the direction of the magnetic field and the direction of the <100> axis of the thin film within the (110) plane is in the range from .+-.27.degree. to .+-.33.degree..

Abstract: A surface magnetostatic wave device includes an Fe-containing garnet single crystal film grown on a gadolinium gallium garnet substrate. The crystallographic plane azimuth of the gadolinium gallium garnet substrate can be one of a (110) plane, a (100) plane, and a (211) plane. The device achieves both a reduced saturation magnetization and a reduced anisotropic magnetic field to thereby minimize the lowest frequency in the propagation band.

Abstract: A signal-to-noise enhancer 10 includes a first 90 degree hybrid set 20. A first output end of the first 90 degree hybrid set 20 is connected to an input end of a limiter used a magnetostatic wave element 62a utilized the magnetostatic surface wave mode. Also, a second output end of the first 90 degree hybrid set 20 is connected to an input end of a filter used a magnetostatic wave element 62b similar to the magnetostatic wave element 62a in structure, via a resistor 32 as a first attenuator. Furthermore, an output end of the limiter is connected to a first input end of a second 90 degree hybrid set 40 via a resistor 52 as a second attenuator. Also, an output end of the filter is connected to a second input end of the second 90 degree hybrid set 40.

Abstract: A magnetostatic wave (MSW) signal-to-noise (S/N) enhancer includes a divider for dividing an input signal into a first and a second path signals, first and second microwave-MSW transducers for transducing the first and second path signals into the first and second path transduced signals, and a combiner for combining the first and second path transduced signals in opposite phase to each other. The first path signal contains a desired signal which is higher than a first saturation level and a noise component which is lower than the first path threshold power level. The first microwave-MSW transducer outputs the noise in linear operation and the desired signal in saturation operation. All the component signals of the second path signal including noise are lower than the second path threshold power level and are output in a linear operation by the second microwave-MSW transducer.

Abstract: A magnetoelastic wave device comprising a substrate, a magnetostrictive film formed over the substrate, a wave generating section, a wave receiving section, and a modulation magnetic field generating section. The magnetostrictive film has an axis of easy magnetization which is substantially <uv0> axis and extends parallel to the major surfaces of the magnetostrictive film.

Abstract: A circuit element utilizing a magnetostatic wave is disclosed which uses a magnetostatic-wave resonator having a structure that a thin YIG (yttrium iron garnet) film is formed on a non-magnetic substrate such as a GGG (gadolinium gallium garnet) substrate. In this resonator, at least a part of end faces of the ferrimagnetic film are made rough such as by lapping with abrasives having a grain size greater than or equal to about 15 .mu.m, to suppress the generation of a unnecessary spurious mode in a wide frequency range.

Abstract: A discriminator having a power divider that divides a signal under test into a signal channel component and a reference channel component. A tunable delay line, such as a magnetostatic wave delay line, inserts a delay into the reference channel. A multielement input transducer selects a narrow band of spin wave wavelengths that are activated, thereby producing frequency discrimination. A phase detector is responsive to both channels to produce an output signal to a spectrum analyzer. A feedback loop, responsive to the output signal of the phase detector automatically places these two components into a quadrature relationship. The discriminator is automatically calibrated by tuning the delay line to values away from the quadrature condition in order to determine the discriminator consant.

Abstract: The invention relates to devices utilizing magnetostatic waves. The invention has as its object a filter microtape which is able to pick up and selectively dissipate magnetostatic waves as a function of their wavelength. The filter microtape is permeable to waves of which the wavelength is a submultiple of its width. The invention is applicable in particular to tunable magnetostatic wave devices such as delay lines, resonators and oscillators.

Abstract: The invention relates to bulk or surface magnetostatic wave devices. The invention provides in the ferrimagnetic substrate of such a device, at least one area with absorption increased by a treatment consisting in local sanding of the substrate or its support to produce several defects by the impact of abrasive particles. The invention is applicable to magnetostatic wave lines and filters.

Abstract: Magnetostrictive rod filter whose attenuation versus frequency curve has a resonance as the conventional magnetostrictive rod filters but also a pole at a frequency near the resonance frequency. The filter comprises a freely vibrating magnetostrictive rod, two windings symmetrically located with respect to the rod center and surrounding the rod, ferrimagnetic material sheaths surrounding the windings except on the parts thereof facing the rod and means for applying a d.c. magnetic field to the rod. The pole of the attenuation curve is due to a demagnetizing field created by portions of the rod externally projecting beyond the windings and by apertures in those parts of the sheaths facing these rod projecting portions.

Abstract: A magnetostrictive mechanical filter comprising at least one rod of a magnetostrictive material forming a resonance element, a spool surrounding the rod, a field coil the windings of which are wound around the spool, and magnets creating a continuous magnetic field, arranged respectively at the ends of the rod, the rod being held radially in at least three points disposed regularly about the rod in the vicinity of the middle portion thereof, a rib being provided at each fixation point, said rib extending parallel to the generatrices of the rod and being formed on the inner peripheral surface of the spool and integrally molded with said spool.