JPH11214212A - Non-reciprocal circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the insertion loss and obtain excellent temperature stability in frequency, by constituting the ratio of saturation magnetization of a permanent magnet and that of microwave ferrite to be greater than the ratio at the time of normal temperature, on both low and high temperature sides. SOLUTION: The ratio (Msm /Msf ) of saturation magnetization (Msm ) of a permanent magnet and saturation magnetization (Msf ) of microwave ferrite is set to be greater than the ratio at the time of normal temperature, on both low and high temperature sides. Temperature coefficient of the microwave ferrite is set to be -0.27 to -0.34%/ deg.C on the high temperature side (60-100 deg.C), and 0 to 0.18%/ deg.C on the low temperature side (-40 to 20 deg.C). The mean value of temperature coefficient of saturation magnetization (Msf ) of a garnet type ferrite is set to be 0 to -0.18%/ deg.C in the temperature region of -40 to 20 deg.C, and -0.27 to -0.34%/ deg.C in the temperature region of 60 to 100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lumped constant type non-reciprocal circuit device used at 100 MHz to 20 GHz, that is, an isolator and a circulator, and to obtain a non-reciprocal circuit device excellent in temperature characteristics. The present invention relates to a magnetic material or a method of temperature compensation for obtaining a non-reciprocal circuit device having excellent insertion loss and temperature characteristics of a center frequency.

[0002]

2. Description of the Related Art Non-reciprocal circuit devices such as isolators and circulators are often used in high-frequency devices using a frequency band of 100 MHz to 20 GHz. This element has a function of passing a high frequency wave in a forward direction at a specific frequency with low loss and blocking a high frequency wave in a reverse direction.

An ordinary lumped-constant type nonreciprocal circuit element includes a permanent magnet, a metal case whose main component is a magnetic yoke, a microwave ferrite to which the magnetic flux of the permanent magnet is applied, and a vicinity of the microwave ferrite. Has a plurality of strip lines and a central conductor arranged in the same and a capacitive element (for example, a capacitive element such as a chip capacitor) electrically connected to the strip line. Usually, the microwave ferrite and the magnet are arranged so as to be stacked.

[0004] If one terminal of a three-terminal circulator, which is one of the non-reciprocal circuit elements, is terminated by a resistor element, the isolator becomes an isolator. The isolator and the circulator are similar in terms of technology and form.

One of the most important characteristics required of such a non-reciprocal circuit device is a loss at the time of passing a high frequency that allows the device to pass in a forward direction, that is, an insertion loss. Needless to say, the smaller the insertion loss, the better. Further, in order for the non-reciprocal circuit device to maintain excellent performance in a wide temperature range, it is necessary that the temperature characteristics of insertion loss be excellent.

On the other hand, another one of the most important characteristics required for the non-reciprocal circuit device is a frequency characteristic. Non-reciprocal circuit elements utilize ferromagnetic resonance, and are usually designed based on the concept of aberresonance (a design method that resonates at a higher magnetic field side than a DC magnetic field at which μ _{+ of a} microwave ferrite becomes maximum). Is done.

[0007] The frequency is set to be the frequency used by the non-reciprocal circuit device. That is, the saturation magnetization of the microwave ferrite (hereinafter, referred to as Ms _f) the saturation magnetization of the size and the permanent magnets (hereinafter, Ms _m and describes) size and approximately determined frequency is used frequency in their ratio of Is set to be

In order for the non-reciprocal circuit device to maintain excellent performance over a wide temperature range, it is important to take measures to prevent the operating frequency from fluctuating even when the environmental temperature changes.

From such a viewpoint, the conventional temperature compensation of the non-reciprocal circuit device has roughly two types of countermeasures and countermeasures. That is, the first method is to make the temperature coefficient of the Ms _f and Ms _m are both reduced.

[0010] For example, in order to reduce the Ms _f is G
d substituted YIG based microwave ferrite employed in, at the same time by selecting a material composition change is small with respect to the temperature of the Ms _f, permanent magnets of high Curie temperature metal system in order to reduce the change of Ms _m, For example, a method of adopting a rare earth magnet and further combining a magnetic shunt steel to adjust the magnetic resistance of the DC magnetic circuit to perform more accurate temperature compensation.

The countermeasure by such a method is disclosed in, for example, Japanese Patent Application Laid-Open No. 31400/1982 and 42544/1982.
No. in the official gazette. In the case of this method, expensive permanent magnets and expensive magnetic shunt steels are naturally used.

Therefore, the second method was to consider whether a ferrite magnet could be used as a less expensive permanent magnet. Since Kiyuri temperature is lower than the metal-based magnet ferrite magnet, as is well known, the temperature coefficient of Ms _m is not necessarily small. However Ms temperature coefficient and Ms operating frequency even if the temperature coefficient is environmental temperature changes if the size of the same order of _m of _f has been assumed that it is possible not vary much.

[0013] Therefore, that the temperature coefficient of the temperature coefficient and Ms _m of Ms _f is selected and combined microwave ferrite and ferrite magnetic material so that the size of the same order was done. In other words, the ratio between the magnitude of the saturation magnetization (Ms _f ) of the microwave ferrite and the strength of the generated magnetic field of the permanent magnet is always constant.

However, even if the nonreciprocal circuit element is supposed to be sufficiently temperature-compensated by the above-mentioned second method, the insertion loss of the element and the temperature characteristics of the center frequency tend to be insufficient at temperatures other than the normal temperature range. Met.

That is, it has not been easy to provide a non-reciprocal circuit device which always has a small insertion loss with respect to a change in environmental temperature and has excellent temperature stability of the operating frequency.

[0016]

The problem to be solved by the present invention is at least one of the problems listed below. (1) Providing an excellent non-reciprocal circuit element over a wide temperature range where insertion loss is wide (2) Providing a stable non-reciprocal circuit element over a wide temperature range where the operating frequency is wide (3) Inserting over a wide temperature range Provision of a non-reciprocal circuit device having excellent loss and a stable operating frequency over a wide temperature range. (4) Provision of an inexpensive, highly reliable non-reciprocal circuit device. (5) At least one of the above-mentioned problems is solved. Providing magnetic materials that can be easily solved. (6) To provide a method for compensating for temperature characteristics which can easily solve at least one of the above-mentioned problems.

[0017]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a non-reciprocal circuit device having a significantly improved configuration, or a magnetic material for obtaining such a non-reciprocal circuit device. Alternatively, a new method for compensating for the temperature characteristics of such a nonreciprocal circuit device has been conceived.

That is, the first invention is a nonreciprocal circuit device which operates at a magnetic field higher than the ferromagnetic resonance magnetic field, and has a ratio of the saturation magnetization (Ms _m ) of the permanent magnet to the saturation magnetization (Ms _f ) of the microwave ferrite. This is a non-reciprocal circuit device configured such that the value of (Ms _m / Ms _f ) is larger than that at normal temperature on both the low temperature side and the high temperature side.

The greatest feature of the present invention, the values of the conventional constant and to was considered the best Ms _m / Ms _f, even in a high temperature side not cold side only, was greater than the value at room temperature There. By reducing only the value of Ms _m / Ms _f of about room temperature is the same thing also result.

With such a configuration, a non-reciprocal circuit device with low loss and small change in operating frequency over a wide temperature range can be obtained. In other words, since this leads to a dramatic improvement in the guarantee standard of the non-reciprocal circuit device, the contribution is extremely large.

Needless to say, since the non-reciprocal circuit device completed as a component is an integral component, separate component configurations suitable for each of the three temperature ranges of low temperature, high temperature and near normal temperature are required. I can't take it.

Although the reason why the configuration as in the first invention is effective is not necessarily theoretically clear from the results of the studies by the inventors, it is considered that the following facts are involved in a complicated manner. Can be

The permeance of the magnetic circuit changes depending on the temperature characteristic of the magnetic permeability and the coefficient of thermal expansion of the magnetic yoke made of Fe. In general, the imaginary part of tensor permeability, which represents the loss of permeability for clockwise circularly polarized waves (usually described as μ ₊ )
The magnitude of the magnetic field must be smaller as the applied magnetic field is farther from the magnetic field causing ferromagnetic resonance. The loss of microwaves leaking or propagating in the permanent magnet in the permanent magnet varies with the environmental temperature.

In the present invention, the normal temperature is a temperature around 20 ° C., the low temperature side is a temperature of about −40 ° C. to 10 ° C., and the high temperature side is a temperature of about 40 ° C. to 100 ° C.

The second invention of the present application is a more specific configuration of the above-described first invention. That is, the second
The invention is directed to a permanent magnet, a magnetic yoke whose main component is a magnetic yoke, a microwave ferrite to which the magnetic flux of the permanent magnet is applied, and a plurality of strip lines arranged near the microwave ferrite. , A capacitive element electrically connected to the strip line, wherein the saturation magnetization (Ms
The temperature coefficient of _f ) is 0% / ° C. to α% / ° C. in the temperature range of −40 ° C. to 20 ° C. (where α is −40 ° C. to 20 ° C. of the saturation magnetization (Ms _m ) of the permanent magnet. And the average value in the temperature range of 60 ° C. to 100 ° C. is (1.5 × β)% / ° C. to (1.9 × β)%.
/ ° C. (where β is the temperature coefficient of the saturation magnetization (Ms _m ) of the permanent magnet at 60 ° C. to 100 ° C.).

In the present invention, at the beginning, "permanent magnet and ...
The part "is a non-reciprocal circuit device" is a general configuration of a conventional lumped constant type non-reciprocal circuit device. Therefore, this part may have another similar configuration. The strip line is a central conductor, and in the case of a three-terminal circulator or a three-terminal isolator, the strip line includes three lines.

The capacitance element is essentially a capacitor,
Recently, there are many chip-type and ceramic-substrate-type ones. The function usually has both the function of impedance matching and the function as a microwave filter.

The temperature coefficient of the saturation magnetization is -40.degree.
The average value in the region of _{20 ℃, ((Ms 20 -Ms} -40) / Ms 20/60) given by × 100, Similarly, the average value in the region of 60 ℃ ~100 ℃, ((Ms 100 - _{ms 60) / ms 20/40} ) bottom right with numbers .Ms is given (a unit is% / ° C. in × 100 are both show the temperature, for example, ms _-40 indicates the saturation magnetization at -40 ° C.. Reference numerals 60 and 40 in the formulas indicate the temperature width (unit: ° C.) of the temperature region. The values of these saturation magnetizations and the temperature characteristics of the saturation magnetizations are measured using a vibrating sample magnetometer (VS
M) can be easily and accurately measured.

[0029] When expressing the present invention from another point of view, when normalized respectively by the value of the temperature characteristics of each Ms _f in their 20 ° C. of the permanent magnets and the microwave ferrite, expressed it in one of FIG. For example, it means that those temperature characteristic lines are in contact with each other near normal temperature, and that the temperature characteristic line of the microwave ferrite has a relationship of two curves such that it is inside the permanent magnet.

In the case where the permanent magnet of the second invention is a ferrite magnet and the microwave ferrite is a garnet-type ferrite, the present invention is the third invention if a specific slope of the temperature characteristic is shown.

That is, the third invention of the present application relates to a permanent magnet,
The main component of the magnetic yoke is a metal case made of iron, a garnet-type ferrite to which the magnetic flux of the permanent magnet is applied, a plurality of central conductors arranged near the garnet-type ferrite, and electrically connected to the central conductor. A permanent magnet is a ferrite magnet, and a temperature coefficient of a saturation magnetization (Ms _f ) of the garnet-type ferrite is in a temperature range of −40 ° C. to 20 ° C. Average value is 0% / ° C to -0.18% / ° C,
And the average value in the temperature range of 60 ° C to 100 ° C is-
It is a non-reciprocal circuit device configured to be 0.27% / ° C. to −0.34% / ° C.

In the present invention, the ferrite magnet is Sr
Ferrite is even better. Ferrite magnets have higher specific resistance than metal magnets, and are effective in reducing loss in a high frequency band. Furthermore, this is compared to the Ba ferrite if Sr ferrite magnets, linearity is good temperature coefficient of the temperature characteristic of the Ms _m can be used in a wide temperature range with about -0.18% / ° C..

The garnet type ferrite is Gd-C
It is even better if it is an a-V-In substitution type YIG. Related to the loss of garnet △ H in addition to (resonance absorption half-width) is small, the material temperature coefficient prescribed in this section is easily be created, and various realizable values of room temperature Ms _f That is, since the setting range of the operating frequency is widened, the application range is widened.

However, realizing the temperature coefficient defined in this section even in the Gd-substituted garnet requires a little room temperature Ms _f
Although the value of is restricted, it is possible. It goes without saying that garnet of another system may be used.

One of the inventions based on such knowledge is as follows.
This is a Gd-Ca-V-In substituted YIG garnet-type ferrite of the fourth invention of the present application. That fourth aspect of the invention, a composition formula _{Gd z Y 3-2x-z Ca 2x} Fe 2-y In y Fe 3-x
V _x O ₁₂ , and 0 <x ≦ 0.7, 0.25 <
The magnetic material satisfies y ≦ 0.4, 0.35 ≦ z ≦ 2.0.

If this magnetic material is applied to the first to third aspects of the present invention, a non-reciprocal circuit device having excellent insertion loss and temperature characteristics of operating frequency can be obtained.

The fifth invention of the present application relates to a method, and the technical content is common to the first invention. That is, the fifth invention of the present application is a method for compensating for the temperature characteristics of a non-reciprocal circuit device operating at a magnetic field higher than the ferromagnetic resonance magnetic field, wherein the saturation magnetization (Ms _m ) of the permanent magnet and the saturation magnetization (Ms _m ) of the microwave ferrite are the value of the ratio (ms _m / ms _f) the ms _f) is, in any of the low temperature side and high temperature side, a method of compensating the temperature characteristic of the nonreciprocal circuit device to be larger than normal temperature.

[0038]

FIG. 1 is an exploded perspective view of a typical non-reciprocal circuit device, in this case, an isolator, for explaining the present invention. FIG. 1 is drawn schematically to ensure visibility, and thus the scale and shape of each part are not accurate.

First, of the structure of the non-reciprocal circuit device, an outline of a portion common to the conventional lumped-constant type non-reciprocal circuit device will be described with reference to FIG. It is as follows. However, it goes without saying that various isolators and circulators other than the type shown in FIG. 1 may be used.

A lower magnetic yoke made of iron is fixed to an insulating substrate having an external terminal electrode, and a copper ground plate (optional) is soldered to the lower magnetic yoke, and a grounding portion of a center conductor is soldered thereon. A disk-shaped microwave ferrite is fixed thereon (for example, heat-bonded with a resin), and one terminal of the strip line portion of the center conductor is bent so as to surround the microwave ferrite. Subsequently, another terminal of the center conductor is similarly bent, and an insulating film (not shown) is sandwiched between the other terminal and the terminal. Repeat the same procedure to fold the remaining terminals.

A disk-shaped permanent magnet was fixed to the upper magnetic yoke prepared beforehand (for example, a method of heating and bonding with resin). The permanent magnet was magnetized with a DC electromagnet to adjust the magnetic force. Put things together.

The extension of the center conductor from the strip line portion is connected to an input / output external terminal provided on the insulating substrate. Further, a chip capacitor for matching is inserted and connected between the extended portion of the center conductor from the strip line portion and the ground plate. There is also a method using a ceramic dielectric substrate instead of the chip capacitor.

The non-reciprocal circuit device thus prepared is accurately set to a desired operating frequency by finely adjusting the magnetic force generated by the permanent magnet.

Here, if the three input / output terminals are arranged and one of them is connected to a ground plate via a resistance element, the remaining two terminals become input terminals and output terminals. An isolator can be made as a terminal.

Next, an outline of an embodiment of the present invention will be described. The temperature characteristics of the saturation magnetization (Ms _m ) and (Ms _f ) of the above-mentioned permanent magnet and microwave ferrite are measured, and their temperature coefficients in a predetermined temperature range are determined and compared. A non-reciprocal circuit element may be selected by using a material selected as a result of the selection.

Alternatively, a ferrite magnet, more preferably an Sr ferrite magnet is used as the permanent magnet, and a garnet-type ferrite is more preferable as the microwave ferrite, and a garnet-type ferrite material having a predetermined composition is more preferable. However, a non-reciprocal circuit element may be used by using these.

The details of the present invention will be described below based on embodiments.

(Example 1) In Example 1, the respective temperature coefficients of the saturation magnetization of an anisotropic Sr ferrite magnet as a permanent magnet and various Gd-Ca-V-In substituted YIGs as microwave ferrites were described. The present invention relates to an experiment performed to clarify the relationship between the insertion loss of a non-reciprocal circuit device and the temperature characteristics of an operating frequency.

First, a commercially available anisotropic Sr ferrite magnet disk was prepared. The temperature characteristic of the saturation magnetization (Ms _m ) is VS
M was measured. Further, as a microwave ferrite, a material having various substitution amounts of Gd-Ca-V-In substitution type YIG was prepared and processed into a disk shape. The temperature characteristics of these saturation magnetizations (Ms _f ) were also measured using VSM.

The procedure for preparing the above-mentioned Gd-Ca-V-In substituted YIG is as follows. All of them are commercially available and special grade reagents Gd ₂ O ₃ , CaCO ₃ , V ₂ O ₅ , In ₂ O ₃ , Y
₂ O _3, and powder was prepared of Fe ₂ O _3.

Further, the composition formula Gd _z Y _3-2x-z Ca _2x Fe
_{2-y In y Fe 3-} x V x O 12 of x, y, z, respectively, x is 0 to 0.7, y is 0 to 0.6, z is is varied is in the range of 0-2 The powder prepared above was weighed so as to obtain a composition having the following composition, and was weighed in ethyl alcohol using a ball mill.
After mixing for an hour, the mixture was dried and crushed to obtain a mixed powder.

These mixed powders were calcined in a ceramic case at 1000 ° C. for 2 hours in an air atmosphere to obtain calcined powder. The calcined powder was pulverized and ground in ethyl alcohol for 24 hours using a ball mill. After drying this,
An aqueous solution of polyvinyl alcohol having a concentration of 10% was solidified, and an equivalent amount of 1% by weight was added thereto, followed by granulation and sizing to obtain raw material granules.

The above-prepared raw material granules are filled in a mold, and are dried to about 100 MPa by a dry press molding method using a hydraulic press.
With the above, a disk-shaped molded body was obtained. These compacts are 1270
It was fired in an oxygen atmosphere at 3 ° C. for 3 hours to obtain a fired body. These fired bodies were subjected to polishing on the outer periphery and upper and lower surfaces to obtain microwave ferrite for non-reciprocal circuit devices.

When these fired bodies were separately confirmed by an X-ray diffraction method, they were almost a garnet single phase. Other basic characteristics, the Ms _f at room temperature 50~130mT
And the ferromagnetic resonance half width ΔH is 560 to 6,90.
0 A / m (However, most samples are 1,800 to 2,100
A / m range).

By combining the above-prepared permanent magnet and various kinds of microwave ferrites, a non-reciprocal circuit device is prepared in the usual manner, and at room temperature of 20 ° C., the insertion loss is minimized and the operating frequency is approximately 300 MHz. The temperature characteristics of the insertion loss were measured for those adjusted to. The measuring instrument and the measuring system are based on a self-made jig composed of a thermostat, a network analyzer, an accurately adjusted cable and a connection terminal.

The measurement points of the insertion loss and the operating frequency of the non-reciprocal circuit device were -10 ° C., 20 ° C., and 80 ° C.
-10 ° C is the midpoint temperature between -40 ° C and 20 ° C, 20 ° C is room temperature, and 80 ° C is the midpoint temperature between 60 ° C and 100 ° C.

Further, the frequency of 300 MHz belongs to the lowest frequency band from the viewpoint of the application, but the low frequency is more advantageous for accurate judgment. Separately about 2GH
By confirming with z, the validity of the judgment was confirmed. That is, it was confirmed that the effect of the present invention did not change at least up to 2 GHz.

FIG. 2 shows the result of the measurement as described above. FIG. 2 shows the saturation magnetization (Ms) of various microwave ferrites.
_f ) Temperature coefficient (however, average value from 60 ° C to 100 ° C)
And the insertion loss at 80 ° C. of each of the isolators prepared using these microwave ferrites. The permanent magnets used at this time were all Sr ferrites (the average value of the temperature coefficient from 60 ° C. to 100 ° C.). Is 0.19%
/ ° C).

According to FIG. 2, the value of the insertion loss is the temperature coefficient of the saturation magnetization (Ms _f ) of the microwave ferrite (6
(Average value at 0 ° C. to 100 ° C.) is in the range of −0.27 to −0.34, which is extremely small, that is, 0.2 dB or less.

It should be further noted that when the temperature coefficient is around 0% / ° C. and when the temperature coefficient is -0.19
% / ° C., the insertion loss was 0.25 in all cases.
dB or more, which is not bad but not the best.

FIG. 3 shows the results of the study on the low temperature side, which were measured in the same manner. Figure 3 is the saturation magnetization of the various microwave ferrite (average value of the proviso -40 ° C. to 20 ° C.) temperature coefficient (Ms _f), at -10 ° C. Each isolator made using these microwave ferrite The average value of the temperature coefficient of the permanent magnet Sr ferrite used at this time at −40 ° C. to 20 ° C. is 0.18% /
° C).

According to FIG. 3, the value of the insertion loss at −10 ° C. is such that the temperature coefficient of the saturation magnetization (Ms _f ) of the microwave ferrite (however, the average value at −40 ° C. to 20 ° C.) is 0 to −−.
If it is within the range of 0.18% / ° C., it is extremely small, that is, 0.2 dB or less.

It should be further noted that the temperature coefficient has an optimum point at a position different from the optimum point at the previous temperature coefficient (60 to 100 ° C.). When the temperature coefficient is 0% / ° C. or more and the temperature coefficient is −0.19% / ° C. or less, the insertion loss is 0.2 dB or more in each case, and it is not a bad value but it is not the best.

FIGS. 4 and 5 show the results of evaluation under the same conditions as the investigations in FIGS. 2 and 3, where the insertion loss is the change in the operating frequency. A negative sign indicates that the operating frequency has been lowered. According to FIG. 4, M is such that the change amount of the operating frequency at 80 ° C. based on 20 ° C. is within 5 MHz.
(average of 60 ° C. to 100 ° C.) the temperature coefficient of s _f is approximately -0.23~-0.36% / ℃.

Further, according to FIG. 5,-
Temperature coefficient of Ms _f such as variation of the operating frequency at 10 ° C. is within 5 MHz (the average value of -40 ° C. to 20 ° C.)
Is approximately −0.4 to + 0.02% / ° C.

It should be noted from the facts shown in FIGS. 4 and 5 that it is difficult to achieve ideal temperature compensation even if the temperature coefficient of the permanent magnet and the temperature coefficient of the microwave ferrite are simply made to coincide with each other. On the low-temperature side,
The reason is that the saturation magnetization of the ferrite should be compensated for to be smaller.

Further, judging from FIG. 2 to FIG. 5 comprehensively,
The temperature coefficient of the microwave ferrite for obtaining a non-reciprocal circuit device having a small insertion loss and a small change in operating frequency is -0.27 to -0.07 on the high temperature side (60 to 100 ° C).
34% / ° C, 0 to 0.18 on low temperature side (-40 to 20 ° C)
% / ° C.

(Example 2) Next, the garnet type microwave ferrite used in Example 1, Gd-Ca-V-
X, y, which are the atomic ratios of the respective element components of the In-substituted YIG.
The relationship between each value of z and the temperature coefficient was examined in detail. The results are shown below.

The temperature coefficient of the saturation magnetization (Ms _f ) of the Gd—Ca—V—In substituted YIG is 0% / ° C. to −0.18% / ° C. in the temperature range of −40 ° C. to 20 ° C. In order to make the average value in the temperature range of 60 ° C. to 100 ° C. to be −0.27% / ° C. to −0.34% / ° C., the following may be performed.

That is, the composition formula Gd _z Y _3-2x-z Ca _2x F
e _2-y In _y Fe _3-x V _x O ₁₂ , 0 <x ≦ 0.7, 0.
The composition may satisfy 25 <y ≦ 0.4 and 0.35 ≦ z ≦ 1.6.

However, even if x> 0.7 and z <0.35, the above condition is satisfied in terms of the temperature coefficient, but
In this case, excessive sintering proceeds, and a low-loss material is not obtained.
Further, when y ≦ 0.25, the crystal grains are fine, so that the loss is not reduced. If y ≧ 0.4, the temperature coefficient on the low temperature side becomes negative, which is not appropriate, and excessive sintering proceeds to worsen the loss. When z <0.35, the temperature coefficient on the low temperature side is excessive, and z>
In the case of 1.6, the temperature coefficient on the high temperature side becomes excessive, which is not desirable.

For example, the composition formula Gd _0.8 Y _1.2 Ca ₁ Fe
_1.7 In _0.3 Fe _2.5 V _0.5 O _12, that is, x = 0.5, y =
The parameters when 0.3 and z = 0.8 were as follows. The microwave ferrite had a saturation magnetization (Ms _f ) at 20 ° C. of 75 mT and a ferromagnetic resonance absorption half width (ΔH) of 1240 A / m. The temperature coefficient is
-0.15% / ° C at -40 ° C to 20 ° C, near 20 ° C
0.17% / ° C, -0.29% / ° C at 60 ° C to 100 ° C
Met.

With respect to the nonreciprocal circuit device manufactured using this microwave ferrite, the insertion loss was 0.19 dB at -10 ° C., 0.17 dB at 20 ° C., and 0.1% at 80 ° C.
8 dB, the operating frequency is 330 MHz at −10 ° C.,
It was 329 MHz at 20 ° C and 330 MHz at 80 ° C.

Example 3 The Sr ferrite magnet of Example 1 was replaced with a commercially available anisotropic Ba ferrite magnet, isotropic samarium-cobalt magnet, and isotropic Nd-Fe-B magnet. The same examination as in Example 1 was performed instead. However, isotropic samarium-cobalt magnet, isotropic Nd
-The Fe-B magnet was formed into a thinner disk than the ferrite magnet in order to adjust the operating frequency.

The temperature characteristics of the saturation magnetization (Ms _m ) of each magnet were measured using a VSM. As a result, the temperature coefficient of each material showed little change with temperature, and the anisotropic Ba ferrite magnet was -0.19%. / ° C, the isotropic samarium-cobalt magnet was −0.04% / ° C., and the isotropic Nd—Fe—B based magnet was −0.12% / ° C.

The optimum temperature coefficient of the microwave ferrite was determined in the same manner as in Example 1. As a result, the same results as in Example 1 were obtained for the anisotropic Ba ferrite magnet.
For the isotropic samarium-cobalt magnet, 0 to -0.4% / C on the low temperature side (-40 to 20C) and -0.6 to -0.8% on the high temperature side (60 to 100C). / ° C was optimal. For isotropic Nd-Fe-B magnets,
0 to -0.12% / ° C on low temperature side, -0.1 on high temperature side
The optimum was 7 to -0.23% / ° C.

According to the above results, the optimum range of the temperature coefficient of the microwave ferrite for the non-reciprocal circuit device is determined by the ratio with the temperature coefficient of the permanent magnet. The temperature coefficient of -40 ° C to 20 ° C is 0 to α% / ° C, and the temperature coefficient of 60 ° C to 100 ° C is (1.
5 × β)% / ° C. to (1.9 × β)% / ° C. was found to be optimal (where α and β are temperature coefficients in the same temperature range of the saturation magnetization (Ms _m ) of the permanent magnet). .

(Embodiment 4) Regarding the relationship between the optimum temperature coefficients found in Embodiment 3, Gd-Ca-VI of Embodiment 3
Gd-substituted YIG, Al-substituted C
It was confirmed in the same manner as in Example 3 when all of the o-doped Ni-based spinel ferrites were replaced with commercial products having various substitution amounts. As a result, the same conclusion as above was obtained.

Further, in order to change the setting of the operating frequency,
When a magnetic field applied to the microwave ferrite was increased and a material having a composition having a higher saturation magnetization (Ms _f ) of the microwave ferrite was selected for trial manufacture, it was confirmed that the above conclusion did not change at least up to 2 GHz.

The structure of the non-reciprocal circuit device in this prototype was different from that shown in FIG. 1 in the following points. The lower magnetic yoke was a substantially flat plate, the upper magnetic yoke was a box having holes, and pin terminals were provided in the holes to serve as input / output terminals. The insulating substrate was omitted. The capacity of the capacitor and the power durability of the resistance element were changed.

[0080]

As described above in detail, according to the present invention, it is possible to provide a non-reciprocal circuit device having a low loss and excellent temperature characteristics of loss and operating frequency. Alternatively, it has become possible to provide a microwave ferrite for the non-reciprocal circuit device. Alternatively, a novel temperature compensation method could be provided ideally.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a non-reciprocal circuit device according to one embodiment of the present invention.

FIG. 2 is a diagram illustrating characteristics of an embodiment according to the present invention.

FIG. 3 is a diagram illustrating characteristics of another embodiment according to the present invention.

FIG. 4 is a diagram illustrating characteristics of another embodiment according to the present invention.

FIG. 5 is a diagram illustrating characteristics of another embodiment according to the present invention.

Claims (5)

[Claims] 1. A non-reciprocal circuit device operating at a magnetic field higher than a ferromagnetic resonance magnetic field, wherein a saturation magnetization (M
s _m ) and the ratio (Ms _m / Ms _f ) of the saturation magnetization (Ms _f ) of the microwave ferrite are larger than those at normal temperature on both the low temperature side and the high temperature side. Reversible circuit element. 2. A permanent magnet, a metal case mainly made of iron, which is a magnetic yoke, a microwave ferrite to which a magnetic flux of the permanent magnet is applied, and a plurality of strip lines arranged near the microwave ferrite And a capacitance element electrically connected to the strip line, wherein the temperature coefficient of saturation magnetization (Ms _f ) of the microwave ferrite in a temperature range of −40 ° C. to 20 ° C. The average value is 0% / ° C. to α% / ° C. (where α is the temperature coefficient of the saturation magnetization (Ms _m ) of the permanent magnet at −40 ° C. to 20 ° C.) in the temperature range of 60 ° C. to 100 ° C. The average value is (1.5 × β)% / ° C. to (1.9 ×
β)% / ° C (where β is the saturation magnetization (Ms
_m ) of 60 ° C. to 100 ° C.). 3. A permanent magnet, a metal case mainly made of iron, which is a magnetic yoke, a garnet-type ferrite to which a magnetic flux of the permanent magnet is applied, and a plurality of strip lines arranged near the garnet-type ferrite. And a capacitance element electrically connected to the strip line, wherein the permanent magnet is a ferrite magnet, and the saturation magnetization (Ms
The temperature coefficient of _f ) is 0% / ° C. to −0.18% / ° C. in the temperature range of −40 ° C. to 20 ° C., and is 60%.
The average value in the temperature range of -100 ° C to -0.27%
/ C to -0.34% / C. 4. Composition formula Gd _z Y _3-2x-z Ca _2x Fe _2-y In
_y Fe _3-x V _x O ₁₂ , and in the above composition formula,
0 <x ≦ 0.7, 0.25 <y ≦ 0.4, 0.35 ≦ z
A magnetic material having a composition satisfying ≦ 1.6. 5. A method for compensating for temperature characteristics of a non-reciprocal circuit device operating at a magnetic field higher than a ferromagnetic resonance magnetic field, comprising: a saturation magnetization (Ms _m ) of a permanent magnet and a saturation magnetization (Ms _f ) of a microwave ferrite. A value of the ratio (Ms _m / Ms _f ) of both the low-temperature side and the high-temperature side is larger than that at normal temperature.