JP2012249174A - Non-reciprocal circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-reciprocal circuit element which can operate stably over a wide range from the high magnetic field side to the low magnetic field side of a magnetic resonance point.SOLUTION: The non-reciprocal circuit element 10 includes a dielectric substrate 12 having a through hole in the center, a columnar magnetic member 14 fitted in the through hole, a conductor 16 formed from one principal surface 14a of the magnetic member 14 to one principal surface 12a of the dielectric substrate 12, a ground conductor 18 formed from the other principal surface 14b of the magnetic member 14 to the other principal surface 12b of the dielectric substrate 12, and a bias magnetic field variable means 20 for applying an internal bias magnetic field variably to the magnetic member 14.

Description

  The present invention relates to a nonreciprocal circuit device, and more particularly to a nonreciprocal circuit device that can be operated in different frequency bands.

  The nonreciprocal circuit element is an electronic component having a function of passing electromagnetic waves only in one direction (irreversible transmission characteristics), and is used to guarantee protection and stable operation of the transmission / reception circuit. In mobile communication systems such as mobile phones, a plurality of frequency bands are used. For example, in a mobile phone in Japan, the frequency band of 800 MHz band or 2 GHz band is used, and the frequency band used by the terminal is set. In addition, the frequency band of mobile phones varies from country to country.

  Therefore, non-reciprocal circuit elements corresponding to different frequency bands are used for terminals using each frequency band. The same applies to non-reciprocal circuit elements in mobile phone base stations installed in each region and country.

  By the way, in the world wireless communication conference held in 2007, the standard of the next generation (fourth generation) mobile communication system (IMT-Advanced) was established, and four frequency bands from 450 MHz to 3.6 GHz are allocated. It was. A conventional non-reciprocal circuit element needs to be tuned for each frequency band.

  However, recently, a nonreciprocal circuit device that can use two frequency bands in one terminal has been proposed (for example, Patent Document 1).

JP-A-10-284909

The nonreciprocal circuit element described in Patent Document 1 is operated at a location where the difference between the real term μ ₊ of the positive circular polarization permeability and the real term μ ₋ of the negative circular polarization permeability is large. It has not been operated in a wide range from the high magnetic field side to the low magnetic field side.

  In addition, since the magnetic member and the conductor having the transmission line portion protruding from the central portion of the same diameter as the magnetic member are laminated, there is a problem that the magnetic field distribution is likely to be disturbed.

  The present invention has been made in consideration of the above-described problems of the prior art, and provides a nonreciprocal circuit device that can operate stably over a wide range from the high magnetic field side to the low magnetic field side of the magnetic resonance point. With the goal.

  The nonreciprocal circuit device according to the first aspect of the present invention includes a dielectric substrate having a through hole in a central portion, a columnar magnetic member fitted in the through hole, and the dielectric from one main surface of the magnetic member. A conductor formed on one main surface of the substrate; and a bias magnetic field variable means for variably applying a bias magnetic field to the magnetic member, wherein the conductor has a diameter smaller than a diameter of the magnetic member. A high magnetic field at the magnetic resonance point of the magnetic member is obtained by integrally changing the bias magnetic field applied by the bias magnetic field varying means, which has a circular part and a transmission line part extending in three directions from the circular part. It is possible to operate in a range from the side to the low magnetic field side.

  According to such a configuration, the magnetic field varying means can be operated over a wide range from the high magnetic field side to the low magnetic field side of the magnetic resonance point, and the magnetic member is fitted into the dielectric substrate. By having a conductor formed from one main surface to one main surface of the dielectric substrate, it is possible to reduce disturbance of the magnetic field distribution due to distortion or chipping of the magnetic member, and to match the impedance of the transmission line of the conductor It becomes easy.

  The non-reciprocal circuit device according to the first aspect of the present invention can be operated with an insertion loss of 0.3 dB or less in both the high magnetic field side and the low magnetic field side of the magnetic resonance point of the magnetic member. In the above range, it has an operating frequency band of 100 MHz or more.

  A non-reciprocal circuit device according to a second aspect of the present invention includes first and second dielectric substrates having a through hole in a central portion, and a cylinder fitted into the through holes of the first and second dielectric substrates, respectively. First and second magnetic members having a shape and formed from one main surface of the first and second magnetic members to one main surface of the first and second dielectric substrates, the first magnetic member and the first magnetic member A dielectric substrate, a conductor sandwiched between the second magnetic member and the second dielectric substrate, and a bias magnetic field variable means for variably applying a bias magnetic field to the first and second magnetic members. And the conductor integrally includes a circular portion having a diameter smaller than the diameters of the first and second magnetic members and a transmission line portion extending in three directions from the circular portion, and the bias magnetic field varying means By changing the bias magnetic field applied in the first, Characterized in that the high magnetic field side of the magnetic resonance points with the beauty second magnetic member is operable in a range leading to downfield.

  According to such a configuration, similarly to the non-reciprocal circuit device according to the first aspect of the present invention, the magnetic resonance point is operated in a wide range from the high magnetic field side to the low magnetic field side, and the disturbance of the magnetic field distribution is reduced. In addition to the fact that the impedance of the transmission line can be easily adjusted, the conductor is sandwiched between the magnetic members, so that it is possible to suppress a loss due to the electromagnetic wave being radiated from the conductor.

  In the nonreciprocal circuit device according to the second aspect of the present invention, as in the nonreciprocal circuit device according to the first aspect of the present invention, in any range between the high magnetic field side and the low magnetic field side of the magnetic resonance point of the magnetic member. Can be operated with an insertion loss of 0.3 dB or less, and has an operating frequency band of 100 MHz or more in the above range.

  In the nonreciprocal circuit device according to the first or second aspect of the present invention, the bias magnetic field varying means includes a permanent magnet and an electromagnet having a core and a coil surrounding a side wall of the core, and the permanent magnet And the core is preferably laminated, and the bias magnetic field varying means is provided on one main surface side of the magnetic member, and on the other main surface side of the magnetic member, A soft magnetic underlayer is preferably provided. Thereby, the magnetic field distribution generated in the magnetic member can be made uniform, and a more stable operation becomes possible.

  Furthermore, in the nonreciprocal circuit device according to the first or second aspect of the present invention, the bias magnetic field varying means is configured by laminating a permanent magnet and a soft magnetic disk having a diameter varying mechanism. And According to such a configuration, the bias magnetic field can be changed over a wide range, and the magnetic field strength can be maintained without supplying energy after changing the magnetic field strength once. Also in this case, the bias magnetic field varying means may be provided on one main surface side of the magnetic member, and a soft magnetic backing layer may be provided on the other main surface side of the magnetic member.

Furthermore, in the nonreciprocal circuit device according to the first or second aspect of the present invention, the transmission line portion includes a first line portion formed from the circular portion to a boundary portion between the magnetic member and the dielectric substrate. A second line part formed on one principal surface of the dielectric substrate, and a connection part interposed between the first line part and the second line part, When the width is W ₁ and the width of the second line portion is W ₂ ,
W ₁ > W ₂
It is. In addition, it is preferable that the connection portion has a shape in which a width is continuously reduced from the first line portion to the second line portion, and further, the length of the first line portion is set to L _1. when the length of the connecting portion was set to L _{2,
L 1/3 ≦ L 2 ≦} 2L 1
It is preferable that With such a configuration, the impedance of the transmission line portion can be matched.

  Further, in the nonreciprocal circuit device according to the first or second aspect of the present invention, the transmission line portion includes a first line portion formed from the circular portion to a boundary portion between the magnetic member and the dielectric substrate, And a second line portion formed on one main surface of the dielectric substrate, and the second line portion is provided with a stub for adding a capacitance component. This also facilitates the impedance matching of the transmission line portion.

  According to the present invention, the magnetic field varying means can be operated over a wide range from the high magnetic field side to the low magnetic field side of the magnetic resonance point, and the magnetic member is fitted into the dielectric substrate, so that By having a conductor formed from the surface to one principal surface of the dielectric substrate, it is possible to reduce the disturbance of the magnetic field distribution due to distortion or chipping of the magnetic member, and to further match the impedance of the transmission line section It becomes easy.

It is sectional drawing of the nonreciprocal circuit device which concerns on 1st Embodiment. It is the top view which looked at the dielectric of the nonreciprocal circuit device which concerns on 1st Embodiment, the magnetic member, and the transmission line part from the one main surface side. It is the figure which showed the frequency characteristic of the magnetic permeability at the time of applying the bias magnetic field 450Oe with respect to the magnetic member which concerns on 1st Embodiment. It is the figure which showed the frequency characteristic of the magnetic permeability at the time of applying the bias magnetic field 300Oe with respect to the magnetic member which concerns on 1st Embodiment. FIG. 5A is a diagram showing transmission characteristics of the nonreciprocal circuit device according to the first embodiment shown in FIG. 3, and FIG. 5B is an enlarged view of insertion loss in the transmission characteristics of FIG. 5A. It is. 6A is a diagram showing transmission characteristics of the nonreciprocal circuit device according to the first embodiment shown in FIG. 4, and FIG. 6B is an enlarged view of insertion loss in the transmission characteristics of FIG. 6A. It is. It is the figure which showed the relationship between the electric current value applied to the coil of the bias magnetic field variable means which concerns on 1st Embodiment, and an internal bias magnetic field. FIG. 8A is a diagram schematically showing the direction of the magnetic field when the current value applied to the coil is positive, and FIG. 8B is a schematic diagram of the direction of the magnetic field when the current value applied to the coil is negative. FIG. It is the figure which showed distribution of the internal magnetic field in a magnetic member in the analysis model of FIG. 8A and FIG. 8B. It is sectional drawing of the nonreciprocal circuit device which concerns on the modification of 1st Embodiment. It is a top view of the conductor which concerns on the modification of 1st Embodiment. It is sectional drawing of the nonreciprocal circuit device which concerns on 2nd Embodiment. FIG. 13A is a plan view showing a state where the diameter of the soft magnetic disk is expanded, and FIG. 13B is a plan view showing a state where the diameter of the soft magnetic disk is reduced. It is the figure which showed the relationship between the diameter of the soft-magnetic disc of the bias magnetic field variable means which concerns on 2nd Embodiment, and an internal bias magnetic field. It is the figure which showed distribution of the internal bias magnetic field of the magnetic member which concerns on 2nd Embodiment. 16A and 16B are diagrams schematically showing the flow of magnetic flux lines when the diameter of the soft magnetic disk is 2.0 mm and 3.2 mm, respectively.

  Hereinafter, the nonreciprocal circuit device according to the present invention will be described in detail with reference to FIGS.

  First, a first embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the non-reciprocal circuit device 10 according to the first embodiment. The nonreciprocal circuit device 10 is incorporated in a communication device such as a mobile phone terminal or a mobile phone base station, and has a function of transmitting a signal in one direction and preventing transmission in the reverse direction.

  The nonreciprocal circuit element 10 includes a dielectric substrate 12 having a through hole in a central portion, a columnar magnetic member 14 fitted in the through hole, and one main surface 14 a of the magnetic member 14. A bias magnetic field is variably applied to the conductor 16 formed over the main surface 12a, the ground conductor 18 formed from the other main surface 14b of the magnetic member 14 to the other main surface 12b of the dielectric substrate 12, and the magnetic member 14. It has a bias magnetic field varying means 20 to be applied.

The dielectric substrate 12 is made of a rectangular ceramic plate. As the ceramic, a nonmagnetic and insulating material can be used. For example, alumina is preferable in that it is excellent in these characteristics and further excellent in mechanical strength. As alumina, for example, one having a dielectric constant of 8 to 10 and a dielectric loss tangent of 1 to 10 × 10 ^{−4 at} a frequency of 1 MHz can be used. The magnetic member 14 is fitted into the through hole in the central portion provided in the dielectric substrate 12. The thickness of the dielectric substrate 12 and the size and shape of the through hole are set in accordance with the magnetic member 14 to be used.

  The magnetic member 14 has a cylindrical shape (disc shape) and is fitted into the through hole of the dielectric substrate 12. The magnetic member 14 and the dielectric substrate 12 may be fitted via a resin such as polyimide, or may be directly fitted with a reduced clearance. For the magnetic member 14, a ferrite having a small magnetic loss and a ferromagnetic resonance half width (ΔH) can be used. For example, nickel zinc ferrite and YIG (yttrium iron garnet) can be suitably used. A YIG single crystal may be used. In this case, the saturation magnetization of the magnetic member 14 is about 850G. As the saturation magnetization of the magnetic member 14, for example, 850G or less, 700G or less, 600G or less can be used.

  FIG. 2 is a plan view of the dielectric substrate 12, the magnetic member 14, and the conductor 16 of the nonreciprocal circuit device 10 according to the first embodiment as viewed from the one principal surfaces 12 a and 14 a side. A conductor 16 is formed from one main surface 14 a of the magnetic member 14 to one main surface 12 a of the dielectric substrate 12. One main surface 14a of the magnetic member 14 and one main surface 12a of the dielectric substrate 12 constitute substantially the same plane. In the conductor 16, a circular portion 22 having a diameter smaller than the diameter of the magnetic member 14 and a transmission line portion 24 projecting in three directions from the circular portion 22 are integrally configured. The conductor 16 is formed by, for example, a method of printing / baking a conductor paste, plating, or attaching a metal foil with a conductive adhesive. Examples of the material of the conductor 16 include Au, Ag, Cu, and Al.

  The ground conductor 18 provided on the other principal surfaces 12b and 14b of the dielectric substrate 12 and the magnetic member 14 is also formed in the same manner as the conductor 16 formed on the one principal surface 12a and 14a. The ground conductor 18 can be provided so as to cover the dielectric substrate 12 and the other main surfaces 12b, 14b of the magnetic member 14.

  One of the three transmission lines 24 is connected to a terminating resistor (not shown), and the signal input from the other transmission line 24 is transmitted to the other. At this time, when the reflected wave from the load connected to the other transmission line unit 24 returns, the reflected wave does not return to the input side but is transmitted to the transmission line unit 24 to which the terminating resistor is connected. Absorbed by the terminating resistor.

The transmission line portion 24 includes a first line portion 24 a formed from the circular portion 22 to a boundary portion between the magnetic member 14 and the dielectric substrate 12, and a second line portion formed on one main surface 12 a of the dielectric substrate 12. 24b, and a connecting portion 24c interposed between the first line portion 24a and the second line portion 24b. Here, as shown in an enlarged partial plan view of the vicinity of the connection portion 24c surrounded by a circle in FIG. 2, the width of the connection portion 24c is W ₁ and the width of the second line portion 24b is W ₂ . When, it is preferable that W ₁ > W ₂ . The connecting portion 24c has a shape in which the width is continuously reduced from the first line portion 24a to the second line portion 24b. Further, _{L 1} the length of the first line portion 24a, when the length of the connecting portion 24c was set to _{L 2,} it is preferred that _{L 1/3 ≦ L 2 ≦} 2L 1.

  The bias magnetic field varying means 20 includes a permanent magnet 26 and an electromagnet 32 having a core 28 and a coil 30 surrounding the side wall of the core 28.

  As the permanent magnet 26, for example, a ferrite magnet such as strontium, barium, or lanthanum-cobalt, or a metal magnet such as samarium-cobalt or neodymium-iron-boron can be used.

The permanent magnet 26 and the core 28 are laminated. For the core 28, for example, it is preferable to use a metal material having an initial permeability μ _i of 1000 or more, more preferably 50000 or more, and even more preferably 100000 or more, and a saturation magnetic flux density B _s of 0.4 T or more. It is preferable to use a metal material of 0.5T or more, more preferably 0.6T or more. For example, an FeNi alloy (permalloy) or an FeCoV alloy (permender) is preferably used. The diameter of the core 28 is preferably larger than at least the diameter of the magnetic member 14.

  One end of the coil 30 surrounding the side wall of the core 28 is connected to a current applying means (not shown), and the other end is grounded.

  The bias magnetic field varying means 20 is provided to face one main surface of the magnetic member 14, and a soft magnetic backing layer 34 is provided to face the other main surface of the magnetic member 14. In the first embodiment, the bias magnetic field varying means 20 is provided on the one main surface 14a side on which the conductor 16 is formed, and the soft magnetic backing layer 34 is provided on the other main surface 14b side on which the ground conductor 18 is formed. However, this may be reversed. That is, the soft magnetic backing layer 34 may be provided on the one main surface 14a side where the conductor 16 is formed, and the bias magnetic field varying means 20 may be provided on the other main surface 14b side where the ground conductor 18 is formed.

For the soft magnetic backing layer 34, it is preferable to use a metal material having an initial permeability μ _i of 1000 or more, more preferably 50000 or more, and even more preferably 100,000 or more, and a saturation magnetic flux density B _s of 0.4 T or more, More preferably, it is preferable to use a metal material of 0.5T or more, more preferably 0.6T or more. For example, the same material as that used for the core 28 can be used, and specifically, an FeNi alloy and an FeCoV alloy can be preferably used.

The non-reciprocal circuit device 10 configured in this way may have a case (yoke) surrounding the outer periphery thereof. In this case, for example, the soft magnetic backing layer 34 may also serve as a case, and the bias magnetic field varying means 20 may be provided outside the case.

  Next, the effect of the nonreciprocal circuit device 10 according to the first embodiment configured as described above will be described with reference to FIGS.

  The nonreciprocal circuit device 10 according to the first embodiment has a configuration in which a magnetic member 14 is fitted in a dielectric substrate 12 as shown in FIG. Thereby, distortion and a chip | tip of the magnetic member 14 can be prevented effectively, and disorder of magnetic field distribution can be reduced. In particular, in the first embodiment, since the bias magnetic field applied to the magnetic member 14 is changed, the magnetic field distribution is likely to be disturbed. With this configuration, a more stable operation is possible.

  In the nonreciprocal circuit element 10, the circular portion 22 of the conductor 16 has a diameter smaller than the diameter of the magnetic member 14. For this reason, since there is no portion that protrudes outside the magnetic member 14, characteristics according to the shape and dimensions of the circular portion 22 can be easily obtained.

Further, the transmission line portion 24 of the conductor 16 has a connection portion 24c interposed between the first line portion 24a and the second line portion 24b, and the first line portion 24a located on the magnetic member 14 has a connection portion 24c. Since the width W ₁ and the width W ₂ of the second line portion 24 b located on the dielectric substrate 12 have a predetermined relationship, suitable impedance matching is possible in the combination of the dielectric substrate 12 and the magnetic member 14. It becomes. Furthermore, the connecting portion 24c has a continuously reduced shape from the first line portion 24a toward the second line portion 24b, the length _{L 2} of the length _{L 1} and the connection portion 24c of the first line portion 24a However, because of the predetermined relationship, impedance matching is further optimized.

FIG. 3 shows the frequency characteristics of the magnetic permeability when a bias magnetic field 450 Oe is applied to the magnetic member 14 (ferrite: dielectric constant 15, saturation magnetization 450 G, ferromagnetic resonance half width 1 Oe) according to the first embodiment. FIG. The dimension of the magnetic member 14 is φ17 mm × 0.62 mm, and has a through-hole matched with the dimension of the magnetic member 14 at the substantially center, and the dielectric substrate 12 (alumina, dielectric constant of 52 mm × 52 mm × thickness 0.62 mm) 9.36, dielectric tangent 0.00024). The circular part 22, the transmission line part 24 and the ground conductor 18 are made of silver having a conductivity of 6.1 × 10 ⁷ S / m, the thickness is 0.01 mm, the diameter of the circular part 22 is 10 mm, and the transmission line part 24 The length of the first line portion 24a is 3.5 mm, the width is 4 mm, and the width of the second line portion 24b is 1.2 mm. The length of the connecting portion 24c between the first line portion 24a and the second line portion 24b is 3 mm, and the width is reduced from 4 mm to 1.2 mm.

In FIG. 3, μ ₊ ′ and μ ₋ ′ are represented by μ _± = μ _± ′ −jμ _± ″, and are real parts of the circularly polarized magnetic permeability μ ₊ and μ ₋ which are complex numbers. Μ ₊ is positive. Circular polarization permeability, μ ₋ means negative circular polarization permeability, μ ₊ ″, μ ₋ ″ represents the imaginary part (loss term), and μ _eff represents effective permeability. The effective permeability μ _eff can be expressed by μ ₊ , μ ₋ as effective permeability μ _eff = 2 μ ₊ μ ₋ / (μ ₊ + μ ₋ ), although it is not shown, it is a loss term. The frequency at which μ ₊ ″ has the maximum value is the magnetic resonance point.

Usually, the nonreciprocal circuit device is used in the region of μ ₊ ′> 0, μ ₊ ′ −μ ₋ ′ <0, or μ ₊ ′> 0, μ ₊ ′ −μ ₋ ′> 0. Further, it has been found that it is possible to operate even in the region of μ ₊ ′> 0 and μ _eff > 0 in relation to the effective magnetic permeability μ _eff . In the case of FIG. 3, in the operating frequency band of 2.3 to 2.4 GHz, there is a relationship of μ ₊ ′> 0 and μ ₊ ′ −μ ₋ ′ <0. It can be seen that the magnetic member 14 can be used in this region.

  The frequency characteristic of the magnetic permeability varies depending on the bias magnetic field applied to the magnetic member 14 and also on the transmission frequency. Therefore, by changing the bias magnetic field according to a desired operating frequency band, a wide frequency band can be obtained. It can be set as the nonreciprocal circuit element 10 which can operate | move.

FIG. 4 shows an example in which the operating frequency band and the bias magnetic field are changed. FIG. 4 is a diagram showing the frequency characteristics of magnetic permeability when a bias magnetic field 300 Oe is applied to the magnetic member 14 according to the first embodiment, that is, the same ferrite as in FIG. 3. In this case, in the operating frequency band of 0.7 to 0.8 GHz, the relationship is μ ₊ ′> 0 and μ ₊ ′ −μ ₋ ′> 0, so that it can be seen that it can be used in this region. The example shown in FIG. 3 shows that it can operate on the high magnetic field side of the magnetic resonance point, but in the example of FIG. 4, it can operate on the low magnetic field side of the magnetic resonance point. It is shown.

  The results of analyzing the transmission characteristics of the nonreciprocal circuit device 10 operating in both bands of the examples shown in FIGS. 3 and 4 are shown in FIGS. 5A to 6B.

  FIG. 5A shows transmission characteristics when a bias magnetic field 450 Oe is applied to the magnetic member 14 as shown in FIG. 3, and FIG. 5B shows the insertion loss. The center frequency of the nonreciprocal operation was 2.38 GHz, and the insertion loss was 0.30 dB. Further, as shown in FIGS. 6A and 6B, transmission characteristics and insertion loss when a bias magnetic field 300 Oe is applied to the magnetic member 14 have a center frequency of nonreciprocal operation of 0.74 GHz and an insertion loss of 0.28 dB. Met.

As described above, the magnetic member 14 according to the first embodiment can be operated in a wide range from the high magnetic field side to the low magnetic field side of the magnetic resonance point by changing the applied bias magnetic field. I understand. The example shown in FIGS. 3 to 6B is an operation in a frequency band away from the magnetic resonance point. However, when operating near the magnetic resonance point, for example, μ ₊ ′> 0, μ _eff > The bias magnetic field may be changed according to the operating frequency so as to have a relationship of zero.

The bias magnetic field applied to the magnetic member 14 can be changed by adjusting the current value applied to the coil 30 in the bias magnetic field varying means 20. FIG. 7 is a diagram showing the relationship between the current value applied to the coil 30 and the bias magnetic field in the bias magnetic field varying means 20. This is an analysis using the bias magnetic field varying means 20 shown in FIG. 1 as a model. For the analysis, a three-dimensional finite element method magnetic field analysis simulator (JMAG, manufactured by Japan Research Institute Solutions) is used, the magnetic member 14 is a YIG single crystal (saturation magnetization 850G, φ1.2 mm), and the permanent magnet 26 (φ1.4 mm, thickness 0). .05 mm), core 28 (FeNi alloy, initial permeability μ _i 150,000, saturation magnetic flux density B _s 0.65T, φ1.6 mm, thickness 0.7 mm), coil 30 (200 turns), soft magnetic backing layer (Soft mag , Backlayer material) 34 (FeNi alloy). Note that the numerical value of the bias magnetic field is at the center of the magnetic member 14 in the thickness direction.

  As shown in FIG. 7, in this case, when the current value is 50 mA, a bias magnetic field of 180 Oe is applied in the direction from the core 28 side toward the soft magnetic backing layer 34. On the other hand, when the current value is −10 mA, a bias magnetic field of 100 Oe is applied in the direction from the soft magnetic backing layer 34 side toward the core 28 side. Model diagrams showing the direction of the magnetic field at this time are shown in FIGS. 8A and 8B.

  FIG. 8A is a model diagram showing the magnetic field direction (magnetic flux line, arrow B) when the current value is 50 mA, and FIG. 8B is the magnetic field direction (arrow C) when the current value is −10 mA. It is the model figure which showed. In FIG. 8A, with respect to the magnetic member 14, the direction of the magnetic field created by the permanent magnet 26 (arrow A) and the direction of the magnetic field created by the coil 30 are the same direction. Thereby, the bias magnetic field strength applied to the magnetic member 14 is increased. On the other hand, in FIG. 8B, the direction of the magnetic field created by the permanent magnet 26 and the direction of the magnetic field created by the coil 30 are opposite to the magnetic member 14. Accordingly, the magnetic field generated by the permanent magnet 26 and the magnetic field generated by the coil 30 cancel each other, and the intensity of the bias magnetic field applied to the magnetic member 14 decreases. Thus, by controlling the current value applied to the coil 30, the bias magnetic field can be variably applied. This is advantageous in realizing multi-band non-reciprocal circuit elements.

  FIG. 9 is a diagram showing the distribution of the internal magnetic field in the magnetic member 14 in the analysis model. When there is no soft magnetic backing layer 34, it can be seen that the magnetic field strength is reduced at the central portion of the magnetic member 14 in both cases of the bias magnetic field 100Oe and 180Oe (indicated by Δ and ▲ in FIG. 9). In particular, in the case of 180 Oe, the magnetic field strength at the center is greatly reduced. On the other hand, in the case of having the soft magnetic backing layer 34 (indicated by ◯ and ● in FIG. 9), it can be seen that the uniformity of the internal magnetic field distribution generated in the center is extremely high. This is because the magnetic circuit is formed by applying the soft magnetic backing layer 34 and a strong magnetic field is applied at the center of the magnetic member 14. Thereby, the magnetic field distribution generated in the magnetic member 14 can be made uniform, and a more stable operation becomes possible.

  FIG. 10 is a cross-sectional view of a non-reciprocal circuit device 40 according to a modification of the first embodiment. The non-reciprocal circuit device 10 employs a so-called microstrip configuration in which a transmission line portion 24 is formed on one exposed main surface 12a of the dielectric substrate 12 and one exposed main surface 14a of the magnetic member 14. On the other hand, in this modification, a so-called strip in which the conductor 46 is sandwiched between the first dielectric substrate 42A and the second dielectric substrate 42B, and the first magnetic member 44A and the second magnetic member 44B. A mold configuration is adopted.

  Also in this non-reciprocal circuit element 40, the first dielectric substrate 42A and the second dielectric substrate 42B have a through hole in the center, and the first magnetic member 44A and the second magnetic member 44B are respectively formed through the through holes. It is inserted in. A conductor 46 is internally provided between one main surface facing the first dielectric substrate 42A and the second dielectric substrate 42B and one main surface facing the first magnetic member 44A and the second magnetic member 44B. ing. A first grounding conductor 48A and a second grounding conductor 48B are provided on each other main surface facing outward.

  FIG. 11 is a plan view showing the conductor 46 with a part thereof omitted. Similarly to the conductor 16, the conductor 46 is formed by a method such as printing and baking of a conductor paste, and has a circular portion 50 having a diameter smaller than the diameter of the first magnetic member 44A and the second magnetic member 44B, A transmission line portion 52 extending in three directions from the circular portion 50 is integrally formed. The transmission line portion 52 includes a first line portion 52a formed from the circular portion 50 to the boundary between the first magnetic member 44A and the second magnetic member 44B and the first dielectric substrate 42A and the second dielectric substrate 42B. And a second line portion 52b extending outward.

Unlike the above-described example of the microstrip type nonreciprocal circuit device 10, the first line portion 52a and the second line portion 52b have the same line width. However, the second line portion 52b is formed with a stub 54 partially expanded. Here, when the width of the stub 54 is S ₁ and the width of the second line portion 52b is W ₂ as shown in the partial plan view in which the vicinity of the stub 54 surrounded by a circle in FIG. 11 is enlarged, S ₁ <W ₂ is preferred. Further, when the length of the stub 54 and the _{S 2,} it is preferable that _{S 1/5 ≦ S 2 ≦} 5S 1.

  According to the nonreciprocal circuit device 40 having such a configuration, the transmission line portion 52 is sandwiched between the first magnetic member 44A and the second magnetic member 44B, and the first dielectric substrate 42A and the second dielectric substrate 42B. For this reason, it is possible to suppress loss due to electromagnetic waves radiated from the transmission line portion 52. Furthermore, impedance matching is facilitated by adding a capacitance component by the stub 54 provided in the second line portion 52b.

  In this modification, the bias magnetic field varying means 20 is provided on the second magnetic member 44B side, but may be on the first magnetic member 44A side, and further on the first magnetic member 44A side and the second magnetic member 44A side. It may be provided on both sides of the magnetic member 44B.

  Next, the nonreciprocal circuit device 60 according to the second embodiment will be described with reference to FIGS. Detailed descriptions and illustrations of the same or common configurations as those of the first embodiment are omitted.

  FIG. 12 is a cross-sectional view of the non-reciprocal circuit device 60 according to the second embodiment. The non-reciprocal circuit element 60 replaces the bias magnetic field varying means 20 that combines the permanent magnet 26 and the electromagnet 32 of the first embodiment shown in FIG. 1 with the permanent magnet 26, the permanent magnet 26, and the soft magnetic layer 62. And a bias magnetic field varying means 66 composed of a soft magnetic disk 64 having a diameter varying mechanism.

  The diameter variable mechanism of the soft magnetic disc 64 has a structure like a drop lid used for cooking, for example. That is, as shown in FIGS. 13A and 13B, the soft magnetic disc 64 has a plurality of fan-shaped pieces 70 provided with elongated holes 68 (slits) provided at the main pins 72 and the arc ends of the respective fan-shaped pieces 70. By connecting the position of the required pin 72 in the long hole 68 of each fan-shaped piece 70, the state shown in FIG. 13A is enlarged, and the diameter is reduced as shown in FIG. 13B. The diameter can be changed between states.

  FIG. 14 is a diagram showing a result of analyzing the relationship between the diameter of the soft magnetic disk 64 and the internal bias magnetic field in the bias magnetic field varying means 66 in the nonreciprocal circuit device 60 according to the second embodiment. The analysis uses a three-dimensional finite element method magnetic field analysis simulator (JMAG, manufactured by Japan Research Institute Solutions), the magnetic member 14 is a YIG single crystal, and a permanent magnet 26 (Nd-Fe-B magnet, φ 2.4 mm, thickness 0.4 mm). ), Soft magnetic disc 64 (permender, YEP-2V, manufactured by Hitachi Metals, minimum diameter 2.0 mm, maximum diameter 4.0 mm, thickness 0.2 mm), soft magnetic layer 62 (permender, diameter 2.0 mm, thickness) 0.2 mm) and a soft magnetic backing layer 34 (permender, diameter 2.0 mm, thickness 0.2 mm). The permanent magnet 26 was set so that a bias magnetic field of 1200 Oe was obtained when the soft magnetic disk 64 had a minimum diameter (2.0 mm).

  As shown in FIG. 14, according to the bias magnetic field varying means 66 according to the second embodiment, by making the diameter of the soft magnetic disk 64 variable from 2.0 mm to 3.2 mm, from the minimum value 100 Oe, It was found that the bias magnetic field can be changed over a wide range up to a maximum value of 1200 Oe that is 10 times or more. In the analysis model according to the second embodiment, the internal bias magnetic field distribution in the magnetic member 14 is uniform according to the presence of the soft magnetic backing layer 34 in FIG. Is high.

  16A and 16B are diagrams schematically showing the flow of magnetic flux lines when the diameter of the soft magnetic disk 64 is 2.0 mm and 3.2 mm, respectively. As can be easily understood from FIGS. 16A and 16B, when the diameter of the soft magnetic disc 64 having a variable diameter is the minimum (2.0 mm), the magnetic flux lines emitted from the permanent magnet 26 expand so much on the way. Since it flows toward the opposing soft magnetic backing layer 34 without being bent, a strong bias magnetic field is applied to the magnetic member 14. On the other hand, when the diameter of the soft magnetic disk 64 is as large as 3.2 mm, most of the magnetic flux lines emitted from the permanent magnet 26 flow in the soft magnetic disk 64 in the horizontal direction, and shortcut to the permanent magnet. Return to the back of 26. Therefore, the internal bias magnetic field applied to the magnetic member 14 becomes extremely small.

  Thus, in the second embodiment, the internal bias magnetic field can be variably applied by adjusting the diameter of the soft magnetic disk 64 as variable. Therefore, it is apparent that the second embodiment can be operated in a wide range from the high magnetic field side to the low magnetic field side of the magnetic resonance point. In this case, the electromagnet 32 used in the first embodiment is not necessary, and it is not necessary to supply energy in order to maintain the magnetic field strength. In addition, the internal bias magnetic field can be changed more easily and widely. It is excellent in that it can be done. This is further advantageous in realizing multi-band non-reciprocal circuit elements.

  Of course, the nonreciprocal circuit elements 10, 40, 60 according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. For example, the configuration may be a combination of the strip-type nonreciprocal circuit element 40 according to the modification of the first embodiment and the bias magnetic field varying means 66 including the variable-diameter soft magnetic disk 64 of the second embodiment.

10, 40, 60 ... Non-reciprocal circuit elements 12, 42A, 42B ... Dielectric substrates 14, 44A, 44B ... Magnetic members 16, 46 ... Conductors 18, 48A, 48B ... Ground conductors 20, 66 ... Bias magnetic field varying means 22, DESCRIPTION OF SYMBOLS 50 ... Circular part 24, 52 ... Transmission line part 24a, 52a ... 1st line part 24b, 52b ... 2nd line part 24c ... Connection part 26 ... Permanent magnet 28 ... Core 30 ... Coil 34 ... Soft magnetic backing layer 64 ... Soft Magnetic disk

Claims (13)

A dielectric substrate having a through hole in the central portion;
A columnar magnetic member fitted in the through hole;
A conductor formed from one main surface of the magnetic member to one main surface of the dielectric substrate;
Bias magnetic field variable means for variably applying a bias magnetic field to the magnetic member;
The conductor integrally includes a circular portion having a diameter smaller than the diameter of the magnetic member, and a transmission line portion extending in three directions from the circular portion,
A nonreciprocal circuit device capable of operating in a range from a high magnetic field side to a low magnetic field side of a magnetic resonance point of the magnetic member by changing a bias magnetic field applied by the bias magnetic field varying means. . The nonreciprocal circuit device according to claim 1,
By changing the bias magnetic field variable by the bias magnetic field changing means, the magnetic member can operate with an insertion loss of 0.3 dB or less in both the high magnetic field side and the low magnetic field side of the magnetic resonance point of the magnetic member. A non-reciprocal circuit device characterized by the above. The nonreciprocal circuit device according to claim 1 or 2,
By changing the bias magnetic field applied by the bias magnetic field varying means, the magnetic resonance point of the magnetic member has an operating frequency band of 100 MHz or more in both the high magnetic field side and the low magnetic field side. A nonreciprocal circuit device characterized by the above. First and second dielectric substrates having a through hole in the central portion;
Columnar first and second magnetic members fitted in the through holes of the first and second dielectric substrates, respectively;
Formed from one main surface of the first and second magnetic members to one main surface of the first and second dielectric substrates; the first magnetic member and the first dielectric substrate; the second magnetic member; A conductor sandwiched between the second dielectric substrates;
Bias magnetic field variable means for variably applying a bias magnetic field to the first and second magnetic members;
The conductor integrally includes a circular portion having a diameter smaller than the diameters of the first and second magnetic members, and a transmission line portion extending in three directions from the circular portion,
By changing the bias magnetic field applied by the bias magnetic field varying means, the magnetic resonance point of the first and second magnetic members can operate in a range from the high magnetic field side to the low magnetic field side. Non-reciprocal circuit element. The non-reciprocal circuit device according to claim 4,
By changing the bias magnetic field that is variable by the bias magnetic field varying means, the insertion loss is reduced in the range of both the high magnetic field side and the low magnetic field side of the magnetic resonance point of the first and second magnetic members. A nonreciprocal circuit device characterized by being operable at 3 dB or less. The nonreciprocal circuit device according to claim 4 or 5,
By changing the bias magnetic field applied by the bias magnetic field varying means, the operation at 100 MHz or higher in both the high magnetic field side and the low magnetic field side of the magnetic resonance point of the first and second magnetic members. A non-reciprocal circuit device characterized by having a frequency band. In the nonreciprocal circuit device according to any one of claims 1 to 6,
The bias magnetic field varying means includes
A permanent magnet, and an electromagnet having a core and a coil surrounding the side wall of the core,
A nonreciprocal circuit device, wherein the permanent magnet and the core are laminated. In the nonreciprocal circuit device according to any one of claims 1 to 6,
The bias magnetic field varying means includes
A non-reciprocal circuit device, wherein a permanent magnet and a soft magnetic disk having a variable diameter mechanism are laminated. The nonreciprocal circuit device according to claim 7 or 8,
The bias magnetic field varying means is provided on one main surface side of the magnetic member,
A nonreciprocal circuit device, wherein a soft magnetic backing layer is provided on the other main surface side of the magnetic member. The non-reciprocal circuit device according to any one of claims 1 to 9,
The transmission line section is
A first line portion formed from the circular portion to a boundary portion between the magnetic member and the dielectric substrate;
A second line portion formed on one main surface of the dielectric substrate;
A connecting portion interposed between the first line portion and the second line portion;
When the width of the first line portion is W ₁ and the width of the second line portion is W ₂ ,
W ₁ > W ₂
A non-reciprocal circuit device characterized by the above. The non-reciprocal circuit device according to claim 10,
The non-reciprocal circuit device, wherein the connection portion has a shape in which a width is continuously reduced from the first line portion to the second line portion. The nonreciprocal circuit device according to claim 10 or 11,
When the length of the first line portion is L ₁ and the length of the connection portion is L ₂ ,
_{L 1/3 ≦ L 2 ≦} 2L 1
A non-reciprocal circuit device characterized by the above. The non-reciprocal circuit device according to any one of claims 1 to 9,
The transmission line section is
A first line portion formed from the circular portion to a boundary portion between the magnetic member and the dielectric substrate;
A second line portion formed on one main surface of the dielectric substrate,
The non-reciprocal circuit device, wherein the second line portion is provided with a stub for adding a capacitance component.

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