JPS61201503A - Magnetic substance resonator - Google Patents

Abstract

PURPOSE:To eliminate the effect on the noise characteristic or the like of an oscillator using a magnetic substance resonator even if the resonance frequency is changed and to improve the purity of signal and to attain broad band by adopting the constitution that an electrode is formed to a ferrite sintered body and a magnetic field is fed thereto. CONSTITUTION:The electrodes 2A, 2B are formed to the ferrite sintering body 1 and a magnetic field H is applied via an exciting coil 3. In applying the magnetic field H, a mus of the ferrite sintered body 1 is changed and in changing the strength of the magnetic field H, the mus of the body 1 and the resonance frequency is changed when the length of the magnetic resonator is made constant. The Q of the magnetic resonator is larger than the Q of the resonator including a varactor diode and the purity of signal is excellent. The variable range of the mus due to the change in the strength of the magnetic field H is large, the change in the resonance frequency is larger than that of a varactor diode and then broad band characteristic is attained.

Description

[Detailed Description of the Invention] [Industrial Application Field] In this invention, the relative magnetic permeability changes depending on the magnetic field. Regarding magnetic resonators.

[Conventional technology]

Resonators used in frequency bands above VHF include dielectric resonators, coaxial resonators, distributed constant circuit resonators equipped with dielectrics such as strip lines, and in particular, in the microwave frequency band, YIG elements are used. YI using the magnetic resonance of
There is a G-camera camera. In the former case, the dielectric constant ε
.

The wavelength shortening rate is determined by the length, and the resonant frequency is uniquely determined by the length. Therefore, when changing the resonant frequency, a variable capacitance diode is used. In the latter case, the resonant frequency is completely variable by changing the strength of the magnetic field.

[Problem that the invention seeks to solve]

Since it is inversely proportional to the QH frequency of the variable capacitance diode, there is a problem that Qfd decreases as the frequency increases, and signal purity decreases due to the decrease in Q. Since the variable capacitance diode C has a small variable width, it cannot be used over a wide band. There is a problem with f-hi. Also.

Since only C is changed by the variable capacitance diode,
Due to these changes, the characteristic impedance of the resonator changes, and this change has a problem in that it affects the noise characteristics of the oscillator or the like in which the resonator is used.

On the other hand, a YIG resonator? The Y-Ding G elements that make up the structure are as follows.

It is a single crystal, must have a spherical shape, and is extremely small, making it difficult to manufacture and handle. Therefore, YIG resonators have the problem of being expensive.

This invention has been made with the aim of solving all of the problems of the prior art.

[Means to solve all problems]

The means for solving the above problems will be explained below with reference to FIG. 1 corresponding to the embodiment. In this invention, electrodes 2A and 2B are formed on a ferrite sintered body 1, and a magnetic field H is applied via an excitation coil 3.

[Effect]

In this configuration, the wavelength shortening rate is
It is small and varies depending on the strength of the magnetic field H, and even if the length of the resonator is constant, the resonant frequency changes due to a change in the wavelength shortening rate.

Furthermore, even if the resonant frequency changes, the characteristic impedance hardly changes.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

In FIG. 1, 1 is a ferrite sintered body and 2A.

2B is an electrode, which is the outer peripheral surface of the ferrite sintered body 1;

It is formed on the inner peripheral surface. Electrodes 2A and 2B.

This is a metallized layer of a good conductor such as gold or silver to reduce loss. H is a magnetic field, which is applied to the ferrite sintered body 1 by the excitation coil 3 via the di-electrode 2A.

The ferrite sintered body 1 is a dielectric material (ε
, = several tens to several hundreds), so if the relative magnetic permeability is μ5, the wavelength shortening rate is proportional to 1/2. therefore,
The wavelength shortening rate of the ferrite sintered body 1 is smaller than that of the conventional one. Therefore, the length of this magnetic resonator can be shorter than the conventional one, assuming the same wavelength.

When a magnetic field H is applied, μ of the ferrite sintered body 1 increases.

When the strength of the magnetic field H is changed, μ5 of the ferrite sintered body 1 changes, and if the length of the magnetic resonator is kept constant, the resonant frequency also changes.

The Q of the magnetic resonator is higher than that of a resonator including a variable capacitance diode, and the signal purity is good.

The variable range of μ due to changes in the strength of the magnetic field H is large, and the change in the resonant frequency is larger than in the case of a variable capacitance diode. By making friends, we can expand our area.

Although μ changes as the strength of the magnetic field H changes, ε5 does not change. However, as the strength of the magnetic field H changes, the thickness of the metallized layer constituting the electrodes 2A and 2Bi changes equimetrically, and as a result, C also changes. Therefore, even if the resonant frequency changes, the rate of change in the characteristic impedance is small.

Therefore, the magnetic resonator does not affect the noise characteristics of an oscillator or the like in which it is used.

Since this magnetic resonator does not have any restrictions on shape or the like like the YIG element resonator, it is easy to manufacture and handle.

Although the resonance mode of the ferrite sintered body 1 is the T 8M mode in this case, it goes without saying that other T M and T E resonators can also be configured in the same shape as the dielectric resonator.

In the above embodiment, the ferrite sintered body 1 is formed into a hollow cylindrical shape, and metallized layers are formed on the outer and inner circumferential surfaces of the electrodes 2A and 2B, but as shown in FIG. - It may be formed by sandwiching two ferrite sintered bodies IA and IB. Even in this case, a metallized layer is required on the outside. This is because the ferrite sintered body is polycrystalline in the direction of the magnetic field H, unlike the YIG core.

There are no restrictions. However, the direction in which the entire magnetic field H is widened is μ5.
Since the variation f is large, it is better to apply the magnetic field H over a wide surface.

[Effects of the Invention] As explained above, in this invention, μ5 changes due to the magnetic field, Q, the variable range of the resonant frequency is large, and the characteristic impedance hardly changes even if the resonant frequency changes. It doesn't hit.

Therefore, according to the present invention, it is possible to improve signal purity and wideband frequency, and also to have the effect that even if the resonance frequency changes, it does not affect the noise characteristics of an oscillator or the like in which a magnetic resonator is used. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the invention, and FIG. 2 is a diagram showing another embodiment of the invention. 1, IA, IFl...ferrite sintered body, 2゜2A,
2B... Electrode, 6... Exciting coil Patent applicant TDC Co., Ltd. Figure 1

Claims (1)

[Claims] 1. A magnetic resonator configured by having electrodes formed on a ferrite sintered body and applying a magnetic field 2. Electrodes formed on the outer and inner peripheral surfaces of the ferrite sintered body A magnetic resonator 3 according to claim 1, wherein the electrode is sandwiched between two ferrite sintered bodies.