Non-reciprocal circuit element

Abstract

To provide a non-reciprocal circuit element for use in the 3 GHz to 6 GHz band.SOLUTION: A non-reciprocal circuit element includes a ferrimagnetic material having a main surface, multiple central conductors arranged on the main surface of the ferrimagnetic material while being insulated from one another, and a laminated magnet formed by stacking ferrite magnets and rare earth magnets containing Sm, and the laminated magnet is arranged facing the multiple central conductors, and the composite temperature coefficient of the remanence of the laminated magnet is between -0.14% / °C and -0.06% / °C, and the slope of the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material is half or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to a non-reciprocal circuit device. [Background technology]

[0002] Non-reciprocal circuit elements include isolators and circulators, and are used in the transmission and reception circuits of devices such as mobile phones and their base stations. Non-reciprocal circuit elements are used to prevent amplifier damage and to obtain stable output power with high linearity, and have the function of causing small insertion loss in the signal transmission direction and large transmission loss in the reverse direction. For example, Patent Document 1 discloses a non-reciprocal circuit element that can be miniaturized. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-267810 Summary of the Invention [Problem to be solved by the invention]

[0004] With the advancement of information and communication technology, there is a demand for transmitting larger amounts of information, and the electromagnetic waves used in information and communication networks such as mobile phone communications are in the high-frequency band capable of transmitting larger amounts of information. Specifically, there is a demand for non-reciprocal circuit elements that are compatible with frequencies in the 3 GHz to 6 GHz band known as the Sub-6 frequency band.

[0005] An object of the present disclosure is to provide a non-reciprocal circuit device suitable for the 3 GHz to 6 GHz band. [Means for solving the problem]

[0006] A non-reciprocal circuit device according to one embodiment of the present disclosure comprises a ferrimagnetic material having a main surface, a plurality of central conductors arranged on the main surface of the ferrimagnetic material in a state insulated from one another, and a laminated magnet in which a ferrite magnet containing Sr and a rare earth magnet containing Sm are stacked, the laminated magnet being arranged opposite the plurality of central conductors, wherein the composite temperature coefficient of the residual magnetic flux density of the laminated magnet is -0.14% / °C or more and -0.06% / °C or less.

[0007] The ferrimagnetic material may have a saturation magnetic flux density of 40 mT or more and 80 mT or less, and a temperature coefficient of the saturation magnetic flux density of -0.45% / °C or more and -0.25% / °C or less.

[0008] The ratio of the thickness of the rare earth magnet to the total thickness of the ferrite magnet and the rare earth magnet may be 1 / 4 or more and 3 / 4 or less.

[0009] In the laminated magnet, the ferrite magnet may be closer to the plurality of central conductors than the rare earth magnet.

[0010] The laminated magnet may have a composite temperature coefficient of residual magnetic flux density of -0.12% / °C or more and -0.08% / °C or less.

[0011] In the frequency characteristics of the insertion loss of the non-reciprocal circuit device, the resonant frequency of the main band and the attenuation pole closest to the resonant frequency may be separated by 200 MHz or more in a temperature range from -40°C to 125°C. [Effects of the Invention]

[0012] According to the embodiments of the present disclosure, a non-reciprocal circuit device suitable for the 3 GHz to 6 GHz band is provided. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is an exploded perspective view showing one embodiment of the non-reciprocal circuit device of the present embodiment. [Figure 2]FIG. 2 shows the magnetic field strength applied to the ferrimagnetic material of the laminated magnet in the temperature range of 5°C to 125°C. [Figure 3A] FIG. 3A shows the frequency characteristics of the VSWR and insertion loss of the non-reciprocal circuit device of Example 1. As shown in FIG. [Figure 3B] FIG. 3B shows the frequency characteristics of the attenuation of the non-reciprocal circuit device of Example 1. [Figure 4A] FIG. 4A shows the frequency characteristics of the VSWR and insertion loss of the non-reciprocal circuit device of Comparative Example 1. As shown in FIG. [Figure 4B] FIG. 4B shows the attenuation frequency characteristics of the non-reciprocal circuit device of Comparative Example 1. As shown in FIG. [Figure 5A] FIG. 5A shows the frequency characteristics of the VSWR and insertion loss of the non-reciprocal circuit device of Comparative Example 2. As shown in FIG. [Figure 5B] FIG. 5B shows the attenuation frequency characteristics of the non-reciprocal circuit device of Comparative Example 2. As shown in FIG. [Figure 6A] FIG. 6A shows frequency characteristics of the input VSWR and insertion loss of the non-reciprocal circuit device of Example 2. As shown in FIG. [Figure 6B] FIG. 6B shows the frequency characteristics of the output VSWR and isolation of the nonreciprocal circuit device of Example 2. [Figure 7A] FIG. 7A shows the frequency characteristics of the input VSWR and insertion loss of the non-reciprocal circuit device of Comparative Example 3. As shown in FIG. [Figure 7B] FIG. 7B shows the frequency characteristics of the output VSWR and isolation of the non-reciprocal circuit device of Comparative Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1 is an exploded perspective view of a non-reciprocal circuit device 30 of this embodiment. The non-reciprocal circuit device 30 is compatible with frequencies in the 3 GHz to 6 GHz band, for example, and is used in the transmitting and receiving circuits of mobile phones and mobile phone base stations. The external dimensions of the non-reciprocal circuit device 30 are, for example, approximately 5 mm in length, 5 mm in width, and 2.5 to 4 mm in height, and the non-reciprocal circuit device 30 is a lumped parameter non-reciprocal circuit device.

[0015] The non-reciprocal circuit device 30 includes a ferrimagnetic material 3, a plurality of central conductors, and a laminated magnet 2.

[0016] The ferrimagnetic material 3 has, for example, a disk shape with a main surface 3a. For example, the diameter of the main surface 3a is approximately 1.5 mm or more and 2.5 mm or less. The ferrimagnetic material 3 preferably has a low saturation magnetic flux density of, for example, 40 mT or more and 80 mT or less, and a low ferromagnetic resonance half-width (ΔH<2500 A / m). Furthermore, the temperature coefficient (temperature dependence) of the saturation magnetic flux density is preferably approximately -0.45% / °C or more and -0.25% / °C or less. Furthermore, the saturation magnetic flux density is preferably 40 mT or more and 70 mT or less, and the low ferromagnetic resonance half-width is preferably ΔH<2000 A / m. The temperature coefficient (temperature dependence) of the saturation magnetic flux density is more preferably approximately -0.4% / °C or more and -0.3% / °C or less. The ferrimagnetic material 3 is made of, for example, a ferrimagnetic compound such as yttrium iron garnet (YIG).

[0017] The multiple central conductors are electrically insulated from one another and are arranged on the main surface 3a of the ferrimagnetic material 3 in a state where they are overlapped and cross each other. In this embodiment, the central conductors 4, 5, and 6 are arranged at an angle of 120°. The ferrimagnetic material 3 and the central conductors 4, 5, and 6 constitute an assembly 20.

[0018] The magnet laminate 2 includes a rare earth magnet 2A and a ferrite magnet 2B. The rare earth magnet 2A includes Sm, and the ferrite magnet includes Sr. The rare earth magnet 2A has a plate shape with main surfaces 2An and 2As, with the north pole located on the main surface 2An side and the south pole located on the main surface 2As side. Similarly, the ferrite magnet 2B has a plate shape with main surfaces 2Bn and 2Bs, with the north pole located on the main surface 2Bn side and the south pole located on the main surface 2Bs side.

[0019] 1, the rare earth magnet 2A and the ferrite magnet 2B are stacked so that the main surface 2An of the rare earth magnet 2A faces the main surface 2Bs of the ferrite magnet 2B. The rare earth magnet 2A and the ferrite magnet 2B need only be stacked close to each other, and the rare earth magnet 2A and the ferrite magnet 2B may be bonded together with an adhesive or the like. The laminated magnet 2 is positioned relative to the assembly 20 so that the main surface 2Bn of the ferrite magnet 2B faces the central conductors 4, 5, and 6.

[0020] The magnetic fields formed by the rare earth magnets 2A and the ferrite magnets 2B are oriented in the same direction, and the magnet stack 2 forms an integrated magnetic field. The magnet stack 2 applies a magnetic field perpendicular to the main surface 3a of the ferrimagnetic material of the assembly 20.

[0021] The rare earth magnet 2A is specifically SmCo5 (1-5 system), Sm2Co 17 (2-17 system), Sm-Fe-N system magnets, etc. Ferrite magnet 2B is an SrO·Fe2O3 system magnet, etc. Table 1 shows the residual magnetic flux density and temperature coefficient of residual magnetic flux density of rare earth magnet 2A and ferrite magnet 2B.

[0022] [Table 1]

[0023] The residual magnetic flux density of the entire magnet laminate 2 is preferably equal to or greater than approximately 0.55 T and equal to or less than approximately 1.0 T. Furthermore, the temperature coefficient of the residual magnetic flux density of the entire magnet laminate 2 is preferably equal to or greater than -0.14% / °C and equal to or less than -0.06% / °C, and more preferably equal to or greater than -0.12% / °C and equal to or less than -0.08% / °C. Hereinafter, the temperature dependence of the residual magnetic flux density of the entire magnet laminate 2 will be referred to as the composite temperature coefficient.

[0024] The remanence (T) and composite temperature coefficient (% / °C) of the entire magnet laminate 2 can be adjusted by changing the materials of the rare earth magnet 2A and ferrite magnet 2B and the ratio of the thicknesses of the respective magnets. For example, if the thickness of the rare earth magnet 2A is Tr and the thickness of the ferrite magnet 2B is Tf, the composite temperature coefficient described above can be achieved by adjusting the ratio of the thickness of the rare earth magnet 2A (Tr) to the total thickness of the rare earth magnet 2A and ferrite magnet 2B (Tr+Tf) between 1 / 4 and 3 / 4.

[0025] More specifically, the above-mentioned composite temperature coefficient can be achieved by constructing the magnet laminate 2 with the thickness ratio shown in Table 2. In Table 2, rare earth magnet 2A is SmCo, which has a temperature coefficient of -0.04 to -0.02% / °C. 17 and ferrite magnet 2B was SrO·Fe2O3 with a temperature coefficient of -0.20 to -0.18% / °C. The external dimensions of laminated magnet 2 are, for example, approximately 3 to 5 mm in length, 3 to 5 mm in width, and 0.8 to 1.2 mm in height when the operating band is 3.6 GHz to 4.0 GHz, and approximately 3 to 5 mm in length, 3 to 5 mm in width, and 0.8 to 2.2 mm in height when the operating band is 4.8 GHz to 5.0 GHz.

[0026] [Table 2]

[0027] Figure 2 shows the magnetic field strength applied to the ferrimagnetic material by the magnet laminate 2 over a temperature range of 5°C to 125°C. Experimental results show that the composite temperature coefficient of the residual magnetic flux density Br of this magnet laminate correlates strongly with the temperature change rate of the applied magnetic field strength. Therefore, in Figure 2, the composite temperature coefficient of the residual magnetic flux density Br is converted into the temperature change rate of the magnetic field strength applied to the ferrimagnetic material and displayed.

[0028] For example, rare earth magnet 2A is Sm2Co 17As mentioned above, when SrO·Fe2O3 is used as ferrite magnet 2B, the temperature change in remanence can be achieved by adjusting the thickness. As such, laminated magnet 2 has a remanence value (0.55 T or more) that cannot be achieved with ferrite magnet SrO·Fe2O3 alone, and a remanence value (0.55 T or more) that cannot be achieved with rare earth magnet Sm2Co 17 It has a composite temperature coefficient of residual magnetic flux density (-0.14% / ℃ or more, -0.06% / ℃ or less) that cannot be obtained by any single element.

[0029] The nonreciprocal circuit device 30 further includes capacitance elements 8, 9, and 10 such as flat capacitors, a resistance element 11, and a resin case 7. The resin case 7 has a recess 13a, in which the assembly 20 is disposed. The capacitance elements 8, 9, and 10 and the resistance element 11 are disposed in recesses 13b, 13c, and 13d provided in the resin case 7, with one end electrically connected to one of the central conductors 4, 5, and 6 and an external terminal provided in the resin case 7, and the other end grounded to the bottom surface of the recess 13a provided in the resin case 7. The nonreciprocal circuit device 30 further includes an upper case 1 and a lower case 12, which are disposed above and below the resin case 7, thereby covering the resin case 7.

[0030] Next, with reference to FIG. 2 and Table 3, the magnetic properties of the magnet laminate 2 of the non-reciprocal circuit device 30 will be described.

[0031] [Table 3]

[0032] As shown in Table 3, conventional non-reciprocal circuit elements with operating bands of 700 MHz to 2.6 GHz have been designed so that the high-frequency characteristics of the non-reciprocal circuit element, specifically the frequency characteristics of VSWR (voltage standing wave ratio), reverse loss, and insertion loss, do not fluctuate significantly in the operating temperature range of the non-reciprocal circuit element, that is, in the temperature range of -40°C to 125°C, by roughly matching the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material and the composite temperature coefficient of the residual magnetic flux density of the magnet.

[0033] The inventors of this application conducted detailed studies on the design of non-reciprocal circuit elements for use in the 3-6 GHz band. They found that in this high-frequency band, the absorption characteristics due to magnetic resonance generated when a DC magnetic field is applied to a ferrimagnetic material react more sensitively to magnetic field strength than the resonance peak of the main-band characteristics of the LC resonant circuit formed by the center conductor and capacitive element. Therefore, when the applied magnetic field decreases under high-temperature conditions, the attenuation pole of magnetic resonance shifts significantly to the low-frequency side. This overlaps with the main-band attenuation pole, resulting in increased insertion loss in the transmission direction and a deterioration in the linearity of the power amplifier output, making it difficult to meet IMD (intermodulation distortion) standards (e.g., -50 dBc max).

[0034] The non-reciprocal circuit device according to the embodiment of the present application is designed differently from conventional non-reciprocal circuit devices, taking into consideration the temperature dependence of the resonance peak of the main band characteristics of the LC resonant circuit and the temperature dependence of the attenuation pole of the magnetic resonance, so that the attenuation pole of the magnetic resonance does not overlap with the main band of the LC resonant circuit in the temperature range of -40°C to 125°C. Specifically, the saturation magnetic flux density of the ferrimagnetic material 3 is set to 40mT to 80mT, which is lower than the value used in conventional non-reciprocal circuit devices. In addition, the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material 3 is set to -0.4% / °C to -0.3% / °C, which is lower than the conventional value. Meanwhile, by using the laminated magnet 2, the composite temperature coefficient of the residual magnetic flux density is reduced to a value lower than that of a single Sm2Co 17 The temperature coefficient is set to between -0.14% / °C and -0.06% / °C, which is difficult to achieve with magnets. In other words, the slope of the composite temperature coefficient of the residual magnetic flux density of the laminated magnet 2 is half or less than that of the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material 3. As a result, as will be explained in the experimental results below, in the insertion loss frequency characteristics of the non-reciprocal circuit device 30, it is possible to separate the main band resonant frequency and the attenuation pole closest to the resonant frequency by 200 MHz or more in the temperature range of -40°C to 125°C. Furthermore, the non-reciprocal circuit device 30 can meet required characteristics such as IMD.

[0035] Patent Document 1 discloses that a low-profile non-reciprocal circuit element can be achieved by reducing the thickness of the permanent magnet in the non-reciprocal circuit element. It describes the use of a rare-earth magnet, which has a higher remanence than an Sr ferrite magnet, to reduce the thickness of the permanent magnet. It also describes that the temperature characteristics of the remanence of a rare-earth magnet are flat, and that replacing an Sr ferrite magnet with a rare-earth magnet does not eliminate the temperature characteristics of the saturation magnetic flux density of a ferrimagnetic material. For this reason, Patent Document 1 discloses the use of a stacked Sr ferrite magnet and an Nd-Fe-B magnet. Although Patent Document 1 discloses the use of two permanent magnets, the temperature characteristics of the remanence obtained by the two permanent magnets must be comparable to the temperature characteristics of the saturation magnetic flux density of the ferrimagnetic material.

[0036] In contrast, in the nonreciprocal circuit device 30 of this embodiment, the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material 3 is made smaller than the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material in conventional nonreciprocal circuit devices, while the composite temperature coefficient of the residual magnetic flux density of the magnet laminate 2 is made larger than the temperature coefficient of the residual magnetic flux density of the permanent magnet in conventional nonreciprocal circuit devices. In other words, the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material 3 and the composite temperature coefficient of the residual magnetic flux density of the magnet laminate 2 are set based on a different concept from conventional ones.

[0037] According to the non-reciprocal circuit device of this embodiment, by using a laminated magnet in which a ferrite magnet containing Sr and a rare earth magnet containing Sm are stacked, the composite temperature coefficient of the residual magnetic flux density can be set to between -0.14% / °C and -0.06% / °C, inclusive. Therefore, a non-reciprocal circuit device with excellent high frequency characteristics and temperature characteristics in the 3 to 6 GHz band can be realized.

[0038] The high frequency characteristics and temperature characteristics of the non-reciprocal circuit device of this embodiment were experimentally determined and the results will be described below.

[0039] FIG. 3A shows the frequency characteristics of VSWR and insertion loss of Example 1, which is a non-reciprocal circuit device of this embodiment, operating in the 4.8 GHz to 5.0 GHz (4.9 GHz band). FIG. 3B shows the frequency characteristics of attenuation over an enlarged frequency range. The magnet stack 2 is made of Sm2Co with a thickness ratio of 1:1. 17 The magnets used were a rare earth magnet 2A made of SrO·Fe2O3 and a ferrite magnet 2B made of SrO·Fe2O3. The residual magnetic flux density was 0.7 to 0.8 T, and the temperature coefficient of the residual magnetic flux density was -0.12% / °C or more and -0.08% / °C or less.

[0040] Figures 3A and 3B show the frequency characteristics obtained at temperatures of -40, 25, 85, 105, 115, and 125°C. The frequency characteristics shift as the temperature increases or decreases. However, as shown in Figure 3A, the VSWR and insertion loss remain sufficiently low in the range from -40°C to 125°C, indicating that good frequency characteristics are obtained. Also, as shown in Figure 3B, as the operating temperature increases, the magnetic resonance attenuation pole A shifts closer to the main band resonance peak P. However, even at 125°C, the main band resonance peak P and the magnetic resonance attenuation pole A are more than 200 MHz apart, so the impact on the main band resonance characteristics is small.

[0041] FIG. 4A shows the non-reciprocal circuit device of Example 1, in which the laminated magnet 2 is replaced with SmCo 17 4A shows the frequency characteristics of VSWR and insertion loss for Comparative Example 1, a non-reciprocal circuit element using a rare earth magnet made of SmCo. FIG. 4B shows the frequency characteristics of attenuation over an expanded frequency range. 17 The rare earth magnet has a residual magnetic flux density of 0.9 to 1.2 T and a temperature coefficient of the residual magnetic flux density of -0.04 to -0.02% / °C.

[0042] As shown in Fig. 4A, as the operating temperature rises, the VSWR and insertion loss increase at the lower end of the operating band. On the other hand, as shown in Fig. 4B, regardless of whether the operating temperature rises or falls, the attenuation pole A of the magnetic resonance is separated from the resonance peak P of the main band by 500 MHz or more. Therefore, in Comparative Example 1, although the attenuation pole A of the magnetic resonance can be well controlled, it can be seen that at high temperatures, the VSWR and insertion loss deteriorate, especially at the lower end of the operating band.

[0043] Figure 5A shows the frequency characteristics of VSWR and insertion loss for Comparative Example 2, a non-reciprocal circuit device that uses a ferrite magnet made of SrO·Fe2O3 instead of laminated magnet 2 in the non-reciprocal circuit device of Example 1. Figure 5B shows the frequency characteristics of attenuation over an expanded frequency range. The ferrite magnet made of SrO·Fe2O3 has a residual magnetic flux density of 0.33 to 0.45 T and a temperature coefficient of residual magnetic flux density of -0.20 to -0.18% / °C.

[0044] As shown in Figure 5A, as the operating temperature rises, the VSWR and insertion loss increase across the entire operating band. Furthermore, as shown in Figure 5B, as the operating temperature rises, the attenuation pole A of the magnetic resonance approaches the resonance peak P of the main band, and at 125°C, it is only about 150 MHz away from the resonance peak P. Therefore, in Comparative Example 2, as the temperature rises, the VSWR and insertion loss deteriorate across the entire operating band, and the influence of the attenuation pole A of the magnetic resonance appears in the resonance peak P.

[0045] FIG. 6A shows the frequency characteristics of the input VSWR and insertion loss of Example 2, a non-reciprocal circuit device of this embodiment operating in the 3.4 GHz to 3.8 GHz (3.6 GHz band). FIG. 6B similarly shows the frequency characteristics of the output VSWR and isolation. The magnet laminate 2 is the same as that of Example 1. As shown in FIGS. 6A and 6B, the input VSWR, output VSWR, insertion loss, and isolation characteristics all maintain sufficiently good values ​​in the temperature range of -40°C to 125°C, demonstrating that good frequency characteristics can be obtained.

[0046] FIG. 7A shows the frequency characteristics of the VSWR and insertion loss on the input side of Comparative Example 3, a non-reciprocal circuit device that uses a ferrite magnet made of SrO·Fe2O3 instead of the laminated magnet 2 in the non-reciprocal circuit device of Example 2. FIG. 7B similarly shows the frequency characteristics of the VSRW and isolation on the output side. As with Comparative Example 2, the ferrite magnet made of SrO·Fe2O3 has a residual magnetic flux density of 0.33 to 0.45 T and a temperature coefficient of residual magnetic flux density of -0.20 to -0.18% / °C. In FIGS. 7A and 7B, the frequency characteristics obtained at temperatures of -40, 25, 85, and 125°C are shown overlapping.

[0047] As shown in Figure 7A, as the operating temperature rises or falls, the input VSWR or insertion loss increases across the entire operating band. Furthermore, as shown in Figure 7B, as the operating temperature rises or falls, the output VSWR increases across the entire operating band, and isolation deteriorates. Therefore, it can be seen that in Comparative Example 3, the input VSWR, output VSWR, insertion loss, and isolation all deteriorate across the entire operating band as the temperature rises or falls.

[0048] When a non-reciprocal circuit device according to an embodiment of the present disclosure was fabricated, it was possible to achieve characteristics of an insertion loss of 1 dB (typ.), an isolation of 10 dB (typ.), and an intermodulation distortion of −60 dBc or less (when 5 W × 2 waves are input) in a product operating in the typical frequency range of 3.4 to 3.8 GHz / bandwidth of 400 MHz, which is included in 5G band n78.

[0049] Furthermore, as can be seen from the above experiments, even when manufacturing a non-reciprocal circuit element for use in a frequency band other than the 3.4 to 3.8 GHz band, ie, 3 GHz to 6 GHz, the configuration of this embodiment is a very effective technique that exhibits little change in characteristics from low to high temperatures, and can achieve low insertion loss, low IMD, and high isolation. [Industrial Applicability]

[0050] The non-reciprocal circuit device of the present disclosure can be used in various bands, and is particularly suitable for use in the 3 to 6 GHz band. [Explanation of symbols]

[0051] 1 Upper case 2. Laminated magnet 2A rare earth magnet 2An, 2As, 2Bn, 2Bs, 3a main surface 2B ferrite magnet 3 Ferrimagnetic materials 4, 5, 6 center conductor 7 Resin case 8, 9, 10 Capacitor elements 12 Lower case 13a~13d Recesses 20 assemblies 30 Non-reciprocal circuit elements

Claims

1. a ferrimagnetic body having a main surface; a plurality of central conductors arranged on a main surface of the ferrimagnetic material in a mutually insulated state; a laminated magnet in which a ferrite magnet and a rare earth magnet containing Sm are stacked, the laminated magnet being disposed opposite the plurality of central conductors; A non-reciprocal circuit element comprising: The composite temperature coefficient of the residual magnetic flux density of the laminated magnet is -0.14% / °C or more and -0.06% / °C or less, and the slope is half or less of the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material. Non-reciprocal circuit element.

2. the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic material is −0.45% / °C or more and −0.25% / °C or less; The saturation magnetic flux density of the ferrimagnetic material is 40 mT or more and 80 mT or less. The non-reciprocal circuit device according to claim 1 .

3. the ratio of the thickness of the rare earth magnet to the total thickness of the ferrite magnet and the rare earth magnet is 1 / 4 or more and 3 / 4 or less; The non-reciprocal circuit device according to claim 1 or 2.

4. In the laminated magnet, the ferrite magnet is closer to the plurality of central conductors than the rare earth magnets; The non-reciprocal circuit device according to claim 1 .

5. the composite temperature coefficient of the residual magnetic flux density of the laminated magnet is -0.12% / °C or more and -0.08% / °C or less; The non-reciprocal circuit device according to claim 1 .

6. the ferrimagnetic material has a ferromagnetic resonance half-width ΔH of less than 2500 A / m; The non-reciprocal circuit device according to claim 1 .

Images