Nonreciprocal circuit element

Abstract

The present application provides a non-reciprocal circuit element suitable for a 3 GHz to 6 GHz band. The non-reciprocal circuit element includes a ferrimagnetic body (3) having a main surface; a plurality of center conductors (4, 5, 6) disposed in an insulating state with respect to each other on the main surface of the ferrimagnetic body; and a laminated magnet that is a laminate of a Sr-containing ferrite magnet (2B) and a Sm-containing rare earth magnet (2A) and is disposed opposite the plurality of center conductors, the laminated magnet having a temperature coefficient of the remanent flux density of the laminated magnet of -0.14% / °C or more and -0.06% / °C or less. The ferrimagnetic body preferably has a saturation flux density of 40 mT or more and 80 mT or less, has a temperature coefficient of the saturation flux density of -0.45% / °C or more and -0.25% / °C or less, and has a low ferromagnetic resonance half-width (ΔH < 2500 A / m).

Description

TECHNICAL FIELD

[0001] The present application relates to a nonreciprocal circuit element. BACKGROUND

[0002] There are isolators, circulators, and the like in nonreciprocal circuit elements, which are used in a transceiving circuit of an apparatus such as a mobile phone and a base station thereof. The nonreciprocal circuit element is used in order to prevent breakage of an amplifier and to obtain a linearly high and stable output power, and has a function in which an insertion loss in a transmission direction of a signal is small and a transmission loss in a reverse direction is large. For example, Patent Literature 1 discloses a nonreciprocal circuit element capable of achieving miniaturization.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2001-267810 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] With the progress of information communication technology, it is required to be able to transmit larger capacity information, and a frequency of an electromagnetic wave used in an information communication network such as mobile phone communication also uses a high frequency band capable of large capacity information transmission. Specifically, a nonreciprocal circuit element capable of coping with a frequency of a 3 GHz to 6 GHz band, which is called a Sub-6 frequency band, is needed.

[0008] An object of the present application is to provide a nonreciprocal circuit element suitable for a 3 GHz to 6 GHz band.

[0009] TECHNICAL MEANS FOR SOLVING THE PROBLEMS

[0010] A nonreciprocal circuit element of one embodiment of the present application includes a ferrimagnetic body having a main surface, a plurality of center conductors arranged in a state of being insulated from each other on the main surface of the ferrimagnetic body, and a laminated magnet that is laminated with a Sr-containing ferrite magnet and a Sm-containing rare earth magnet, and is arranged opposite to the plurality of center conductors, and a temperature coefficient of a saturation magnetic flux density of the ferrimagnetic body is -0.45% / °C or more and -0.25% / °C or less.

[0011] The saturation magnetic flux density of the ferrimagnetic body can be 40 mT or more and 80 mT or less, and a temperature coefficient of the saturation magnetic flux density is -0.45% / °C or more and -0.25% / °C or less.

[0012] A ratio of a thickness of the rare earth magnet to a total thickness of the ferrite magnet and the rare earth magnet can be 1 / 4 or more and 3 / 4 or less.

[0013] In the laminated magnet, the ferrite magnet can be positioned closer to the plurality of center conductors than the rare-earth magnet.

[0014] The temperature coefficient of the Br of the laminated magnet can also be -0.12% / °C or more and -0.08% / °C or less.

[0015] In the frequency characteristics of the insertion loss of the nonreciprocal circuit element, the resonance frequency of the main frequency band and the attenuation pole closest to the resonance frequency can also be 200 MHz or more apart within a temperature range of -40°C to 125°C.

[0016] Effects of the Invention

[0017] According to the embodiment of the present invention, a nonreciprocal circuit element suitable for a 3 GHz to 6 GHz band can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is an exploded perspective view showing one embodiment of the nonreciprocal circuit element of the present embodiment.

[0019] Figure 2 shows the applied magnetic field intensity of the laminated magnet to ferrimagnetic bodies within a temperature range of 5°C to 125°C.

[0020] Figure 3A shows the frequency characteristics of the VSWR and the insertion loss of the nonreciprocal circuit element of Example 1.

[0021] Figure 3B shows the frequency characteristics of the attenuation degree of the nonreciprocal circuit element of Example 1.

[0022] Figure 4A shows the frequency characteristics of the VSWR and the insertion loss of the nonreciprocal circuit element of Comparative Example 1.

[0023] Figure 4B shows the frequency characteristics of the attenuation degree of the nonreciprocal circuit element of Comparative Example 1.

[0024] Figure 5A shows the frequency characteristics of the VSWR and the insertion loss of the nonreciprocal circuit element of Comparative Example 2.

[0025] Figure 5B shows the frequency characteristics of the attenuation degree of the nonreciprocal circuit element of Comparative Example 2.

[0026] Figure 6A shows the frequency characteristics of the input-side VSWR and the insertion loss of the nonreciprocal circuit element of Example 2.

[0027] Figure 6BFrequency characteristics of the input side VSWR and the insertion loss of the nonreciprocal circuit element of Example 2.

[0028] Figure 7A Frequency characteristics of the input side VSWR and the insertion loss of the nonreciprocal circuit element of Comparative Example 3.

[0029] Figure 7B Frequency characteristics of the output side VSWR and the isolation of the nonreciprocal circuit element of Comparative Example 3. DETAILED DESCRIPTION

[0030] Figure 1 is an exploded perspective view of the nonreciprocal circuit element 30 of the present embodiment. The nonreciprocal circuit element 30 is, for example, suitable for a frequency of a 3 GHz to 6 GHz band, and is used for a transceiving circuit of a mobile phone and a base station of a mobile phone. The size of the outer shape of the nonreciprocal circuit element 30 is, for example, 5 mm in length, 5 mm in width, and 2.5 to 4 mm in height, and the nonreciprocal circuit element 30 is a lumped constant type nonreciprocal circuit element.

[0031] The nonreciprocal circuit element 30 includes a ferrimagnetic body 3, a plurality of center conductors, and a laminated magnet 2.

[0032] The ferrimagnetic body 3 is, for example, a circular plate shape having a main surface 3a. The diameter of the main surface 3a is, for example, 1.5 mm or more and 2.5 mm or less. The ferrimagnetic body 3 is, for example, preferably a low saturation magnetic flux density of 40 mT or more and 80 mT or less, and a low ferromagnetic resonance half-width (ΔH < 2500 A / m). In addition, the temperature coefficient (temperature dependence) of the saturation magnetic flux density is preferably -0.45% / °C or more and -0.25% / °C or less. Further, 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 -0.4% / °C or more and -0.3% / °C or less. The ferrimagnetic body 3 is, for example, composed of a ferrimagnetic compound such as yttrium iron garnet (YIG).

[0033] The plurality of center conductors are electrically insulated from each other, and are arranged in a state of being overlapped in a crisscross manner on the main surface 3a of the ferrimagnetic body 3. In the present embodiment, the center conductors 4, 5, and 6 are arranged at an angle of 120° with respect to each other. The ferrimagnetic body 3 and the center conductors 4, 5, and 6 constitute a combination 20.

[0034] The laminated magnet 2 includes a rare-earth magnet 2A and a ferrite magnet 2B. The rare-earth magnet 2A contains Sm. Further, the ferrite magnet contains Sr. The rare-earth magnet 2A is in a plate shape having a main surface 2An and a main surface 2As, with an N pole on the main surface 2An side and an S pole on the main surface 2As side. Likewise, the ferrite magnet 2B is in a plate shape having a main surface 2Bn and a main surface 2Bs, with an N pole on the main surface 2Bn side and an S pole on the main surface 2Bs side.

[0035] As shown in FIG. 2, the rare-earth magnet 2A and the ferrite magnet 2B are laminated in such a manner that the main surface 2An of the rare-earth magnet 2A opposes the main surface 2Bs of the ferrite magnet 2B. The rare-earth magnet 2A and the ferrite magnet 2B can be bonded by an adhesive or the like, as long as they are laminated in close proximity. The laminated magnet 2 is disposed with respect to the assembly 20 in such a manner that the main surface 2Bn of the ferrite magnet 2B opposes the center conductor 4, 5, 6. Figure 1

[0036] The magnetic fields formed by the rare-earth magnet 2A and the ferrite magnet 2B are oriented in the same direction, and the laminated magnet 2 forms a single magnetic field. The laminated magnet 2 applies a magnetic field perpendicularly to the main surface 3a of the ferrimagnetic body of the assembly 20.

[0037] The rare-earth magnet 2A is specifically SmCo5 (1-5 series), Sm2Co 17 (2-17 series), Sm-Fe-N series magnet, or the like. The ferrite magnet 2B is a SrO / Fe2O3 series magnet or the like. Table 1 shows the residual magnetic flux density and the temperature coefficient of the residual magnetic flux density of the rare-earth magnet 2A and the ferrite magnet 2B.

[0038] [Table 1]

[0039]

[0040] The residual magnetic flux density of the laminated magnet 2 as a whole is preferably 0.55 T or more and 1.0 T or less. Further, the temperature coefficient of the residual magnetic flux density of the laminated magnet 2 as a whole is preferably -0.14% / °C or more and -0.06% / °C or less, and more preferably -0.12% / °C or more and -0.08% / °C or less. Hereinafter, the temperature dependence of the residual magnetic flux density of the laminated magnet 2 as a whole is referred to as a resultant temperature coefficient.

[0041] ​The value of the residual magnetic flux density (T) and the value of the temperature coefficient of the resultant (% / °C) of the entire laminated magnet 2 can be adjusted by changing the materials of the rare-earth magnet 2A and the ferrite magnet 2B and the thickness ratio of each magnet. For example, in a case where the thickness of the rare-earth magnet 2A is Tr and the thickness of the ferrite magnet 2B is Tf, the above-mentioned temperature coefficient of the resultant 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 the ferrite magnet 2B (Tr + Tf) to be between 1 / 4 or more and 3 / 4 or less.

[0042] More specifically, for example, the above-mentioned temperature coefficient of the resultant can be achieved by configuring the laminated magnet 2 with the thickness ratio shown in Table 2. In Table 2, as the rare-earth magnet 2A, Sm2Co 17 with a temperature coefficient of -0.04 to -0.02 % / °C is used, and as the ferrite magnet 2B, SrO / Fe2O3 with a temperature coefficient of -0.20 to -0.18 % / °C is used. The dimensions of the outer shape of the laminated magnet 2 are, for example, in a case where the use frequency band is 3.6 GHz to 4.0 GHz, 3 to 5 mm in length, 3 to 5 mm in width, and 0.8 to 1.2 mm in height, and in a case where the use frequency band is 4.8 GHz to 5.0 GHz, 3 to 5 mm in length, 3 to 5 mm in width, and 0.8 to 2.2 mm in height.

[0043] [Table 2]

[0044] Tr: Tf Synthesis temperature coefficient (% / °C) 1﹕3 -0.14 1﹕1 -0.1 3﹕1 -0.06

[0045] Figure 2 The applied magnetic field strength of the laminated magnet 2 to the ferrimagnetic body in the temperature range of 5°C to 125°C is shown. According to the experimental results, the temperature coefficient of the resultant of the residual magnetic flux density Br of the laminated magnet and the temperature change rate of the applied magnetic field strength have a strong correlation. Therefore, in the following table, the temperature coefficient of the resultant of the residual magnetic flux density Br is converted into the temperature change rate of the applied magnetic field strength to the ferrimagnetic body and is shown. Figure 2

[0046] For example, the temperature change of the residual magnetic flux density achieved by adjusting the thickness in a case where Sm2Co 17 is used as the rare-earth magnet 2A and SrO / Fe2O3 is used as the ferrite magnet 2B is shown as above. In this way, the laminated magnet 2 has a value of the residual magnetic flux density (0.55 T or more) that cannot be obtained with the ferrite magnet SrO / Fe2O3 alone and a temperature coefficient of the resultant of the residual magnetic flux density of a value that cannot be obtained with the rare-earth magnet Sm2Co 17 alone (-0.14 % / °C or more, -0.06 % / °C or less).

[0047] ​The nonreciprocal circuit element 30 further includes capacitor elements 8, 9, 10 such as flat plate capacitors, a resistance element 11, and a resin housing 7. The resin housing 7 has a recess 13a in which the assembly 20 is disposed. The capacitor elements 8, 9, 10 and the resistance element 11 are disposed in recesses 13b, 13c, 13d provided in the resin housing 7, one end of each being electrically connected to any one of the center conductors 4, 5, 6 and an external terminal provided on the resin housing 7, and the other end being grounded at the bottom surface of the recess 13a provided in the resin housing 7. The nonreciprocal circuit element 30 further includes an upper housing 1 and a lower housing 12 which cover the resin housing 7 by being disposed above and below the resin housing 7.

[0048] Next, the magnetic properties of the laminated magnet 2 of the nonreciprocal circuit element 30 will be described with reference to Figure 2 and Table 3.

[0049] [Table 3]

[0050]

[0051] As shown in Table 3, with the existing nonreciprocal circuit element using a frequency band of 700 MHz or more and 2.6 GHz or less, by making the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body and the resultant temperature coefficient of the residual magnetic flux density of the magnet substantially identical, the high frequency properties, specifically, the frequency characteristics of the VSWR (voltage standing wave ratio), the reverse loss, and the insertion loss of the nonreciprocal circuit element are designed to not greatly change in the temperature range of -40°C or more and 125°C or less as the use temperature of the nonreciprocal circuit element.

[0052] The present inventors have conducted detailed studies on the design of a nonreciprocal circuit element used in a frequency band of 3 to 6 GHz. As a result, it has been known that, in such a high frequency band, the absorption characteristics caused by the magnetic resonance occurring when a DC magnetic field generated by a magnet is applied to a ferrimagnetic body react more sensitively to the magnetic field strength than the resonance peak of the main frequency band characteristics of an LC resonance circuit formed by a center conductor and a capacitor element. Therefore, it has been known that, when the magnetic field is decreased under a high temperature condition, the attenuation pole of the magnetic resonance greatly moves to the low frequency side, the attenuation pole overlaps the main frequency band, and thus the insertion loss in the transmission direction deteriorates, or the linearity of the power amplifier output deteriorates, making it difficult to satisfy the standard (for example, -50 dBc max) of IMD (intermodulation distortion).

[0053] In the non-reciprocal circuit element of the embodiment of the present application, the temperature dependence of the resonance peak of the main band characteristic of the LC resonance circuit and the temperature dependence of the decay pole of the magnetic resonance are considered, and a design different from that of the conventional non-reciprocal circuit element is performed so that the decay pole of the magnetic resonance does not overlap the main band of the LC resonance circuit in the temperature range of -40°C or higher and 125°C or lower. Specifically, the saturation magnetic flux density of the ferrimagnetic body 3 is set to be 40 mT or higher and 80 mT or lower, which is smaller than the value used in the conventional non-reciprocal circuit element. Further, the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body 3 is set to be -0.4% / °C or higher and -0.3% / °C or lower, which is smaller than the conventional one. On the other hand, by using the laminated magnet 2, the resultant temperature coefficient of the residual magnetic flux density is set to be -0.14% / °C or higher and -0.06% / °C or lower, which is larger than that of the permanent magnet of the conventional non-reciprocal circuit element. In summary, the resultant temperature coefficient of the residual magnetic flux density of the laminated magnet 2 is 1 / 2 or lower in comparison with the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body 3. Thereby, as explained in the experimental results below, in the frequency characteristic of the insertion loss of the non-reciprocal circuit element 30, the resonance frequency of the main band and the decay pole closest to the resonance frequency can be separated by 200 MHz or more in the temperature range of -40°C to 125°C. Further, the non-reciprocal circuit element 30 can satisfy the required characteristics such as IMD. 17 the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body 3 is 1 / 2 or lower in comparison with the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body 3. Thereby, as explained in the experimental results below, in the frequency characteristic of the insertion loss of the non-reciprocal circuit element 30, the resonance frequency of the main band and the decay pole closest to the resonance frequency can be separated by 200 MHz or more in the temperature range of -40°C to 125°C. Further, the non-reciprocal circuit element 30 can satisfy the required characteristics such as IMD.

[0054] In addition, Patent Literature 1 discloses a technique of realizing a low posture (low height) non-reciprocal circuit element by reducing the thickness of the permanent magnet of the non-reciprocal circuit element. It is described that, in order to reduce the thickness of the permanent magnet, a rare-earth magnet having a larger residual magnetic flux density Sr than a ferrite magnet is used; in the case where the ferrite magnet is replaced with the rare-earth magnet in which the temperature characteristic of the residual magnetic flux density of the rare-earth magnet is flat, the temperature characteristic of the saturation magnetic flux density of the ferrimagnetic body cannot be eliminated. Therefore, Patent Literature 1 discloses a technique of overlappingly using an Sr ferrite magnet and an Nd-Fe-B system magnet. Patent Literature 1 discloses a technique of using two permanent magnets, but it is necessary to make the temperature characteristic of the residual magnetic flux density obtained by the two permanent magnets be the same degree as the temperature characteristic of the saturation magnetic flux density of the ferrimagnetic body.

[0055] In contrast, in the non-reciprocal circuit element 30 of the present embodiment, the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body 3 is made smaller than the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body of the conventional non-reciprocal circuit element, and the resultant temperature coefficient of the residual magnetic flux density of the laminated magnet 2 is made larger than the temperature coefficient of the residual magnetic flux density of the permanent magnet of the conventional non-reciprocal circuit element. That is, the temperature coefficient of the saturation magnetic flux density of the ferrimagnetic body 3 and the resultant temperature coefficient of the residual magnetic flux density of the laminated magnet 2 are set in a different concept from the prior art.

[0056] According to the non-reciprocal circuit element of the present embodiment, by providing the laminated magnet composed of the Sr-containing ferrite magnet and the Sm-containing rare earth magnet laminated, the temperature coefficient of the residual magnetic flux density can be set to -0.14% / °C or more and -0.06% / °C or less. Thus, the non-reciprocal circuit element having excellent high frequency characteristics and temperature characteristics in the frequency band of 3 to 6 GHz can be realized.

[0057] Hereinafter, the results of the high frequency characteristics and the temperature characteristics of the non-reciprocal circuit element of the present embodiment obtained by experiments are described.

[0058] Figure 3A The frequency characteristics of the VSWR and the insertion loss of the non-reciprocal circuit element of the present embodiment, that is, Example 1, using the frequency band of 4.8 GHz to 5.0 GHz (4.9 GHz band) are shown. Figure 3B The frequency characteristics of the attenuation degree are shown with the frequency range enlarged. In the laminated magnet 2, the Sm2Co 17 magnet 2A composed of Sm2Co

[0059] In Figure 3A and Figure 3B , the frequency characteristics obtained at the temperatures of -40, 25, 85, 105, 115, and 125°C are shown overlapped. As the temperature rises or falls, the frequency characteristics move. However, as shown in Figure 3A , in the range of -40°C to 125°C, the VSWR and the insertion loss maintain very low values, and good frequency characteristics are obtained. Further, as shown in Figure 3B , when the use temperature is allowed to rise, the attenuation pole A of the magnetic resonance moves in a manner to approach the resonance peak P of the main frequency band, but at 125°C, the resonance peak P of the main frequency band and the attenuation pole A of the magnetic resonance are also separated by 200 MHz or more, and the influence on the resonance characteristics of the main frequency band is small.

[0060] Figure 4A The frequency characteristics of the VSWR and the insertion loss of the non-reciprocal circuit element, that is, Comparative Example 1, in which the laminated magnet 2 of Example 1 is replaced with the rare earth magnet composed of Sm2Co 17 Figure 4B The frequency characteristics of the attenuation degree are shown with the frequency range enlarged. The Sm2Co 17 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.

[0061] As​Figure 4A As shown, as the use temperature rises, the VSWR and the insertion loss increase at the lower end of the use frequency band. On the other hand, as shown, regardless of whether the use temperature rises or falls, the attenuation pole A of the magnetic resonance departs from the resonance peak P of the main frequency band by 500 MHz or more. Therefore, it is known that in Comparative Example 1, the attenuation pole A of the magnetic resonance can be controlled smoothly, but when it becomes a high temperature, particularly at the lower end side of the use frequency band, the VSWR and the insertion loss deteriorate. Figure 4B As shown, as the use temperature rises, the VSWR and the insertion loss increase at the lower end of the use frequency band. On the other hand, as shown, regardless of whether the use temperature rises or falls, the attenuation pole A of the magnetic resonance departs from the resonance peak P of the main frequency band by 500 MHz or more. Therefore, it is known that in Comparative Example 1, the attenuation pole A of the magnetic resonance can be controlled smoothly, but when it becomes a high temperature, particularly at the lower end side of the use frequency band, the VSWR and the insertion loss deteriorate.

[0062] Figure 5A Frequency characteristics of the VSWR and the insertion loss of a nonreciprocal circuit element in which the laminated magnet 2 is replaced with a ferrite magnet composed of SrO / Fe2O3 in the nonreciprocal circuit element of Example 1, that is, Comparative Example 2, are shown. Figure 5B The frequency characteristics of the attenuation degree are shown with a frequency range enlarged. The residual flux density of the ferrite magnet composed of SrO / Fe2O3 is 0.33 to 0.45 T, and the temperature coefficient of the residual flux density is -0.20 to -0.18 % / °C.

[0063] As shown, as the use temperature rises, the VSWR and the insertion loss increase at the lower end of the use frequency band. On the other hand, as shown, regardless of whether the use temperature rises or falls, the attenuation pole A of the magnetic resonance departs from the resonance peak P of the main frequency band by 500 MHz or more. Therefore, it is known that in Comparative Example 1, the attenuation pole A of the magnetic resonance can be controlled smoothly, but when it becomes a high temperature, particularly at the lower end side of the use frequency band, the VSWR and the insertion loss deteriorate. Figure 5A As shown, as the use temperature rises, the VSWR and the insertion loss increase at the lower end of the use frequency band. On the other hand, as shown, regardless of whether the use temperature rises or falls, the attenuation pole A of the magnetic resonance departs from the resonance peak P of the main frequency band by 500 MHz or more. Therefore, it is known that in Comparative Example 1, the attenuation pole A of the magnetic resonance can be controlled smoothly, but when it becomes a high temperature, particularly at the lower end side of the use frequency band, the VSWR and the insertion loss deteriorate. Figure 5B As shown, as the use temperature rises, the VSWR and the insertion loss increase at the lower end of the use frequency band. On the other hand, as shown, regardless of whether the use temperature rises or falls, the attenuation pole A of the magnetic resonance departs from the resonance peak P of the main frequency band by 500 MHz or more. Therefore, it is known that in Comparative Example 1, the attenuation pole A of the magnetic resonance can be controlled smoothly, but when it becomes a high temperature, particularly at the lower end side of the use frequency band, the VSWR and the insertion loss deteriorate.

[0064] Figure 6A Frequency characteristics of the VSWR and the insertion loss of the input side of the nonreciprocal circuit element of the present embodiment in which the use frequency band is 3.4 GHz to 3.8 GHz (3.6 GHz band), that is, Example 2, are shown. Figure 6B The frequency characteristics of the VSWR and the isolation of the output side are also shown. The laminated magnet 2 is the same as in Example 1. As shown by Figure 6A and Figure 6B As shown, as the use temperature rises, the VSWR and the insertion loss increase at the lower end of the use frequency band. On the other hand, as shown, regardless of whether the use temperature rises or falls, the attenuation pole A of the magnetic resonance departs from the resonance peak P of the main frequency band by 500 MHz or more. Therefore, it is known that in Comparative Example 1, the attenuation pole A of the magnetic resonance can be controlled smoothly, but when it becomes a high temperature, particularly at the lower end side of the use frequency band, the VSWR and the insertion loss deteriorate.

[0065] Figure 7A Frequency characteristics of the VSWR and the insertion loss of the input side of the nonreciprocal circuit element in which the laminated magnet 2 is replaced with a ferrite magnet composed of SrO / Fe2O3 in the nonreciprocal circuit element of Example 2, that is, Comparative Example 3, are shown. Figure 7BThe frequency characteristics of the output-side VSRW and the isolation are shown in the same manner. As in Comparative Example 2, the residual flux density of the ferrite magnet composed of SrO / Fe203was 0.33 to 0.45 T, and the temperature coefficient of the residual flux density was -0.20 to -0.18% / °C. In Figure 7A and Figure 7B The frequency characteristics obtained at temperatures of -40, 25, 85, and 125°C are shown superimposed.

[0066] As shown in Figure 7A , the input-side VSWR or the insertion loss increases throughout the use frequency band as the use temperature rises or falls. Further, as shown in Figure 7B , the output-side VSWR increases throughout the use frequency band when the use temperature is raised or lowered, and the isolation deteriorates. Thus, it is known that in Comparative Example 3, any of the characteristics of the input-side VSWR, the output-side VSWR, the insertion loss, and the isolation deteriorate throughout the use frequency band as the temperature rises or falls.

[0067] The non-reciprocal circuit element of the embodiment of the present application was produced, and in a product including a representative frequency range of 3.4 to 3.8 GHz band / bandwidth of 400 MHz in the 5G band n78, characteristics such as an insertion loss of 1 dB (typ.), an isolation of 10 dB (typ.), and an intermodulation distortion of -60 dBc or less (at the time of 5W x 2 wave input) were achieved.

[0068] Further, it is known from the above experiment that in the case of the non-reciprocal circuit element used in other frequency bands than the 3.4 to 3.8 GHz band, the structure of the embodiment is also a very effective technology capable of achieving a small change in characteristics from low temperature to high temperature, low insertion loss, and low IMD, high isolation.

[0069] Industrial applicability

[0070] The non-reciprocal circuit element of the present application can be used in various frequency bands, and is particularly preferably used in a frequency band of 3 to 6 GHz.

[0071] Explanation of reference numerals

[0072] 1 upper housing

[0073] 2 laminated magnet

[0074] 2A rare earth magnet

[0075] 2An, 2As, 2Bn, 2Bs, 3a main surface

[0076] 2B ferrite magnet

[0077] 3 ferrimagnetic body

[0078] 4, 5, 6 center conductor

[0079] 7 resin case

[0080] 8, 9, 10 capacitor element

[0081] 12 lower case

[0082] 13a-13d recess

[0083] 20 combination

[0084] 30 non-reciprocal circuit element

Claims

1. A non-reciprocal circuit element, characterized by, Comprising: a ferrimagnetic body having a main surface; a plurality of center conductors arranged on the main surface of the ferrimagnetic body in an insulating state from each other; and a laminated magnet composed of a Sr-containing ferrite magnet and a Sm-containing rare earth magnet, and arranged opposite to the plurality of center conductors, a temperature coefficient of the resultant residual flux density of the laminated magnet is -0.14% / °C or more and -0.06% / °C or less, and a slope of the temperature coefficient of the resultant residual flux density of the laminated magnet compared to a temperature coefficient of a saturated flux density of the ferrimagnetic body is 1 / 2 or less, in a frequency characteristic of an insertion loss of the nonreciprocal circuit element, a resonance frequency of a main frequency band and an attenuation pole closest to the resonance frequency are apart by 200 MHz or more in a temperature range of -40°C to 125°C.

2. The nonreciprocal circuit element according to claim 1, wherein: a temperature coefficient of a saturated flux density of the ferrimagnetic body is -0.45% / °C or more and -0.25% / °C or less, the saturated flux density of the ferrimagnetic body is 40 mT or more and 80 mT or less.

3. The nonreciprocal circuit element according to claim 1 or 2, wherein: a ratio of a thickness of the rare earth magnet to a total thickness of the ferrite magnet and the rare earth magnet is 1 / 4 or more and 3 / 4 or less.

4. The nonreciprocal circuit element according to claim 1 or 2, wherein: in the laminated magnet, the ferrite magnet is closer to the plurality of center conductors than the rare earth magnet.

5. The nonreciprocal circuit element according to claim 1 or 2, wherein: a temperature coefficient of the resultant residual flux density of the laminated magnet is -0.12% / °C or more and -0.08% / °C or less. ​

Images