Abstract: A ferromagnetic resonator is disclosed, in which perpendicular ferrimagnetic resonance of thin film YIG is utilized. The resonator comprises a ferrimagnetic YIG thin film and a microstrip line coupled to the YIG thin film operative in a bias magnetic field applied perpendicular to a major surface of the YIG thin film. The YIG thin film disk has a magnetization distribution of magnetostatic mode, and the microstrip line is designed to generate a high-frequency magnetic field distribution similar to the magnetization distribution of the uniform mode (1, 1).sub.1. In such arrangement, coupling between the high-frequency magnetic field and magnetization of high sprious mode is reduced.

Abstract: A ferrimagnetic resonator is disclosed which is stabilized upon temperature deviation and operable over a wide frequency range. The resonator comprises a ferrimagnetic thin film resonance element, a temperature detector for the resonance element a bias magnetic field generating coil, a compensation coil and a compensation circuit. The compensation circuit has a pre-coded compensation data upon operation temperature range and generates a compensation signal in response a detected temperature of the resonance element. The compensation signal is then fed to the compensation coil to generate an additional magnetic field to the resonance element thus the resonance frequency of the resonance element is stabilized upon temperature.

Abstract: Disclosed is a YIG thin film device utilizing ferrimagnetic resonance effect, a magnetic circuit having a gap of length lg where the YIG thin film device being provided and applying a bias magnetic field perpendicular to a film surface of the YIG thin film device, the magnetic circuit including a permanent magnet having a thickness lm and a soft magnetic plate having a thickness lx, the permanent magnet satisfying the characteristics ##EQU1## the soft magnetic plate satisfying the characteristics ##EQU2## wherein fo is resonance frequency of the YIG thin film device,.gamma. is gyromagnetic ratio of the YIG thin filmNz.sup.Y is demagnetization factor of the YIG thin film4.pi.Mso.sup.Y is saturation magnetization of the YIG thin film at room temperature,4.pi.Mso.sup.x is saturation magnetization of the soft magnetic plate,Br.sup.o is remanence of the permanent magnet at room temperature,.alpha..sub.1.sup.B is first order temperature coefficient of the remanence of the permanent magnet near room temperature,.

Abstract: A YIG film microwave device utilizing the ferrimagnetic resonance of a YIG film, comprising a YIG film microwave element formed by a liquid phase epitaxial growth process and a photolithographic process, and a magnetic circuit including permanent magnets for applying a DC magnetic field to the YIG film microwave element. Some of the Fe.sup.3+ ions of the YIG film are substituted by nonmagnetic ions to provide the YIG film microwave device with satisfactory temperature characteristics. The YIG film microwave device is capable of operating stably over the wide range of working frequency and that of temperature.

Abstract: A signal converter comprises a filter formed of a first ferromagnetic resonator which supplied with an input signal that is to be converted and produces a filtered signal having a first frequency, a local oscillator formed of an active element and a second ferromagnetic resonator connected to the active element, produces an oscillating signal having a second frequency, a mixer receives and mixes the filtered signal and oscillating signal and produces a converted signal, the first ferromagnetic resonator is formed of a first ferrimagnetic crystal, a microstrip line magnetically coupled to the ferrimagnetic crystal and a first D.C. bias magnetic field means which applies a first D.C. bias magnetic field to the first ferrimagnetic crystal, the second ferromagnetic resonator is formed of a second ferrimagnetic crystal, a second microstrip line is magnetically coupled to the second ferrimagnetic crystal, and a second D.C. bias magnetic field means which applies a second D.C.

Abstract: Disclosed herein is a magnetic apparatus comprising: a magnetic circuit including magnetic yoke and a magnet, with a magnetic gap formed in the circuit for forming a uniform d.c. bias magnetic field in the magnetic gap; a magnetic device made of magnetic material of certain composition and placed in the magnetic gap so that the device operates in the d.c. bias magnetic field; and a soft magnetic plate provided in the magnetic gas, the soft magnetic plate being made of magnetic material having composition substantially identical to the composition of the magnetic device.

Abstract: A ferromagnetic resonator comprises a nonmagnetic substrate, a ferrimagnetic thin film element formed on a major surface of the nonmagnetic substrate, a strip line for example formed on another major surface of the nonmagnetic substrate and electromagnetically coupled to the ferrimagnetic thin film element, a conductive wall facing the strip line and spaced therefrom a predetermined distance, an end of the strip line being connected by the conductive wall to ground potential and a bias magnetic field source applying a D.C. magnetic field to the ferrimagnetic thin film perpendicular to the major surface thereof. Such an arrangement enables a drastic reduction in the effective dielectric constant of the transmission lines, whereby a filter with a high center frequency of the order of at least ten gigahertz can be achieved despite the short type structure.

Abstract: Apparatus for varying the magnetic field in a magnetic resonant element which comprises a magnetic yoke with one or more magnets mounted within the magnetic yoke so as to generate a substantially uniform magnetic field in the magnetic yoke and a plurality of magnetic resonance elements located in the magnetic field formed by the magnet and including adjusting means for varying the magnetic reluctance between the magnetic yoke and the magnet at a position which is opposite the position of the plurality of magnetic resonance elements. The magnetic reluctance can be varied to arrive at the desired strength of the magnetic field.

Abstract: A tuned oscillator is disclosed which comprises an active element, a resonator electrically connected to the active element and made of a magnetic material using ferro-magnetic resonance phenomenon, and a magnetic circuit for applying a magnetic field to the resonator. The resonator is made of an YIG (yttrium, iron and garnet) thin film magnetic resonance element formed by a thin film forming technique and utilizes an uniform mode ferro-magnetic resonance in the YIG thin film, and operating under the application of magnetic field of the magnetic circuit.

Abstract: A ferromagnetic resonator employing a disk of ferrimagnetic material is disclosed. The ferromagnetic resonator comprises a disk of ferrimagnetic material such as yttrium iron garnet (YIG) and a magnet applying D.C. magnetic field perpendicularly to a surface of the disk, and microstrip line applying RF magnetic field to the disk. The disk of ferrimagnetic material is processed to have a groove at a predetermined position on one surface of the disk, or to have a predetermined area in a central portion of the disk with a thickness smaller than that of peripheral portion of the disk, so that spurious response caused by magnetostatic mode other than the uniform mode is suppressed.

Abstract: A phase detector for detecting a mutual phase difference between two signals, such as first and second microwave signals, comprises first and second signal paths for being supplied with first and second input signals of the same frequency, respectively, and providing with a predetermined additional mutual phase difference between the first and second input signals at their output ends and a field effect transistor having a pair of input electrodes connected to the output ends of the first and second signal paths, respectively, and an output electrode from which an output signal representing a mutual phase difference which the first and second input signals have originally therebetween is derived. The first and second input signals at the input electrodes of the field effect transistor have the original mutual phase difference which is to be detected and the predetermined additional mutual phase difference added by the first and second signal paths therebetween.

Abstract: Dielectric resonator stabilized micro-strip oscillators in which micro-strip lines are provided to the first, second and third terminals of the active element for oscillation and in which a dielectric resonator coupled at a predetermined position to one of the micro-strip lines which is not used as an output terminal is disclosed. In the integrated microwave oscillator, there is an active element for oscillation such, for example, as GaAs-FET having first, second and third terminals. Micro-strip lines connect to the first and third terminals, and a micro-strip line connected between the first and third terminals form a feedback circuit, together with the first mentioned micro-strip lines. A dielectric resonator is coupled to one of these micro-strip lines which is not used as an output terminal at a predetermined location.