Non-reciprocal circuit elements

Abstract

This non-reciprocal circuit element comprises a metal layer, a loss layer, and a magnet. The metal layer comprises a first terminal, a second terminal, and a third terminal. The loss layer comprises a magnetic body and an absorber. The magnetic body overlaps with a first region of the metal layer in a thickness direction. The absorber overlaps with a second region of the metal layer in the thickness direction. The magnet and the metal layer sandwich at least the magnetic body in the thickness direction. When viewed from the thickness direction, the shortest width between a first side connecting the first terminal with the second terminal of the metal layer and a second side of the absorber on the first terminal / second terminal side is shorter than the width between a first straight line connecting both ends of the first side and a second straight line connecting both ends of the second side.

Description

[Technical Field]

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

[0002] A non-reciprocal circuit element is an element that determines the transmission direction of a high-frequency signal. Isolators and circulators are examples of non-reciprocal circuit elements. Non-reciprocal circuit elements are widely used in circuits that transmit high-frequency signals.

[0003] Non-reciprocal circuit elements are used in various places where high frequency signals are used. For example, Patent Document 1 discloses an isolator for microwave communication. Also, for example, Patent Document 2 describes the use of an isolator in a quantum computer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-287403 [Patent Document 1] Patent No. 6998459 Summary of the Invention [Problem to be solved by the invention]

[0005] As the frequency of the input signal increases, the isolation characteristics of the isolator deteriorate.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-reciprocal circuit element whose isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides the following means.

[0008] (1) A non-reciprocal circuit device according to this embodiment includes a metal layer, a lossy layer, and a magnet. The metal layer includes a first terminal, a second terminal, and a third terminal. The lossy layer includes a magnetic material and an absorber. The magnetic material overlaps a first region of the metal layer in the thickness direction. The absorber overlaps a second region of the metal layer in the thickness direction. The first region extends between the first terminal and the second terminal. The second region extends between the first terminal and the third terminal and between the second terminal and the third terminal. The magnet and the metal layer sandwich at least the magnetic material in the thickness direction. When viewed from the thickness direction, the shortest width between a first side of the metal layer connecting the first terminal and the second terminal and a second side of the absorber on the first and second terminal sides is shorter than the width between a first straight line connecting both ends of the first side and a second straight line connecting both ends of the second side.

[0009] (2) In the non-reciprocal circuit device according to the above aspect, the width between the first side and the second side may be shortest at the midpoint of the first side.

[0010] (3) In the non-reciprocal circuit device according to the above aspect, the first side may be bent or curved toward the second straight line.

[0011] (4) In the non-reciprocal circuit device according to the above aspect, the second side may be bent or curved toward the first straight line.

[0012] (5) In the non-reciprocal circuit device according to the above aspect, the first side may be bent or curved toward the second straight line, and the second side may be bent or curved toward the first straight line.

[0013] (6) In the non-reciprocal circuit device according to the above aspect, the minimum width may satisfy the following formula (1): In formula (1), W1 is the minimum width, f0 is the maximum frequency of an input signal input to the first terminal or the second terminal, ε0 is the permittivity of a vacuum, μ0 is the magnetic permeability of a vacuum, and ε effis the effective dielectric constant of the magnetic material at frequency f0, and μ eff is the effective permeability of the magnetic body at the frequency f0 when a DC magnetic field is applied to the magnetic body from the magnet.

[0014]

number

[0015] (7) In the non-reciprocal circuit device according to the above aspect, the third terminal may be grounded directly or via a resistor. [Effects of the Invention]

[0016] The non-reciprocal circuit device according to the present invention is less likely to experience a decrease in isolation characteristics even when a high-frequency input signal is input. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of a non-reciprocal circuit device according to a first embodiment. [Figure 2] FIG. 2 is a plan view of a metal layer and a loss layer of the nonreciprocal circuit device according to the first embodiment. [Figure 3] FIG. 2 is a plan view of a metal layer of the non-reciprocal circuit board according to the first embodiment. [Figure 4] FIG. 2 is a plan view of a loss layer of the non-reciprocal circuit board according to the first embodiment. [Figure 5] FIG. 2 is a plan view of the conductors and magnets of the non-reciprocal circuit board according to the first embodiment. [Figure 6] FIG. 10 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a first modified example. [Figure 7] FIG. 10 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a second modified example. [Figure 8] FIG. 10 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a third modified example. [Figure 9] FIG. 10 is a cross-sectional view of a non-reciprocal circuit device according to a fourth modified example. [Figure 10]FIG. 4 is a cross-sectional view of a non-reciprocal circuit device according to a second embodiment. [Figure 11] FIG. 10 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a second embodiment. [Figure 12] FIG. 10 is a plan view of a metal layer of a non-reciprocal circuit board according to a second embodiment. [Figure 13] FIG. 10 is a plan view of a loss layer of a non-reciprocal circuit board according to a second embodiment. [Figure 14] FIG. 11 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a fifth modified example. [Figure 15] FIG. 13 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a sixth modified example. [Figure 16] FIG. 13 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a seventh modified example. [Figure 17] FIG. 10 is a cross-sectional view of a non-reciprocal circuit device according to a third embodiment. [Figure 18] FIG. 10 is a plan view of a metal layer and a loss layer of a nonreciprocal circuit device according to a third embodiment. [Figure 19] 1 shows the measurement results of isolation characteristics of the non-reciprocal circuit devices according to Example 1, Example 2, and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present embodiment will be described in detail below with reference to the drawings as appropriate. The drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate changes can be made within the scope of the effects of the present invention.

[0019] First, let us define directions. The x-direction is the direction along the surface of the metal layer. For example, the direction connecting the first and second terminals of the metal layer is the x-direction. The y-direction is the direction perpendicular to the x-direction along the surface of the metal layer. The z-direction is the direction perpendicular to the x-direction and y-directions. The thickness direction of each layer is an example of the z-direction.

[0020] "First embodiment" 1 is a cross-sectional view of a non-reciprocal circuit device 101 according to a first embodiment. The non-reciprocal circuit device 101 includes, for example, a metal layer 10, a first loss layer 21, a second loss layer 22, a first magnet 31, a second magnet 32, a first conductor 41, and a second conductor 42. The non-reciprocal circuit device 101 functions, for example, as an isolator.

[0021] Fig. 2 is a plan view of the metal layer 10 and the first loss layer 21 of the nonreciprocal circuit element 101 according to the first embodiment. Fig. 1 is a cross section taken along line AA in Fig. 2. Fig. 3 is a plan view of the metal layer 10 of the nonreciprocal circuit element 101 according to the first embodiment. Fig. 4 is a plan view of the first loss layer 21 of the nonreciprocal circuit element 101 according to the first embodiment.

[0022] The metal layer 10 has a first terminal T1, a second terminal T2, and a third terminal T3. The first terminal T1, the second terminal T2, and the third terminal T3 correspond to, for example, the vertices of a triangle. The first terminal T1 and the second terminal T2 are connected to external terminals. The third terminal T3 is, for example, an open end.

[0023] The metal layer 10 transmits high-frequency signals. The metal layer 10 transmits high-frequency signals non-reciprocally between the first terminal T1 and the second terminal T2. "Transmitting high-frequency signals non-reciprocally" means that the signal propagation efficiency differs depending on the direction. For example, if a signal propagates with low loss in the forward direction but hardly propagates in the reverse direction, this corresponds to "transmitting high-frequency signals non-reciprocally." The propagation direction of the high-frequency signal in the metal layer 10 is controlled by the first loss layer 21 and the second loss layer 22, which will be described later.

[0024] A high-frequency signal input from the first terminal T1 is transmitted with low loss to the second terminal T2. A high-frequency signal input from the second terminal T2 is transmitted with low loss to the third terminal T3. A high-frequency signal input from the third terminal T3 is transmitted with low loss to the first terminal T1. A high-frequency signal input from the second terminal T2 reaches the first terminal T1 via the third terminal T3, but is almost entirely absorbed. In other words, the high-frequency signal is hardly transmitted from the second terminal T2 to the first terminal T1. In other words, the high-frequency signal is transmitted with low loss from the first terminal T1 to the second terminal T2, but is hardly transmitted from the second terminal T2 to the first terminal T1.

[0025] There is no particular limitation on the metal layer 10 as long as it transmits high-frequency signals with high efficiency. The metal layer 10 is made of, for example, aluminum, copper, silver, gold, stainless steel, etc. The metal layer 10 may also be made by plating a non-conductor or a conductor with a high resistance value (e.g., phosphor bronze) with aluminum, copper, silver, gold, stainless steel, etc.

[0026] The metal layer 10 has a first region 11 and a second region 12. The first region 11 extends between the first terminal T1 and the second terminal T2. The first region 11 overlaps with the first magnetic body 25 in the z direction. The second region 12 extends between the first terminal T1 and the third terminal T3 and between the second terminal T2 and the third terminal T3. The second region 12 overlaps with the first absorber 26 in the z direction. In a plan view from the z direction, there are boundaries between the first region 11 and the second region 12 between the first terminal T1 and the third terminal T3 and between the second terminal T2 and the third terminal T3.

[0027] The first side S1 of the metal layer 10, which connects the first terminal T1 and the second terminal T2, is bent. The first side S1 is bent toward the third terminal T3 side from the first straight line L1. The first side S1 is bent toward the second straight line L2. The first straight line L1 is a straight line connecting the first end S1A and the second end S1B of the first side S1. The second straight line L2 is a straight line connecting the first end S2A and the second end S2B of the second side S2, which will be described later.

[0028] The first loss layer 21 and the second loss layer 22 sandwich the metal layer 10 in the z direction. The first loss layer 21 includes a first magnetic body 25 and a first absorber 26. The second loss layer 22 includes a second magnetic body 27 and a second absorber 28. The first loss layer 21 and the second loss layer 22 have substantially the same shape. The first loss layer 21 is located between the metal layer 10 and the first magnet 31. The second loss layer 22 is located between the metal layer 10 and the second magnet 32.

[0029] The first magnetic body 25 and the first absorber 26 are located at different positions in the xy plane. The second magnetic body 27 and the second absorber 28 are located at different positions in the xy plane. The first magnetic body 25 and the second magnetic body 27 are located at positions overlapping with the first region 11 of the metal layer 10 in the z direction. The first absorber 26 and the second absorber 28 are located at positions overlapping with the second region 12 of the metal layer 10 in the z direction.

[0030] The first magnetic body 25 and the second magnetic body 27 may have any shape as long as they can cover the first region 11. The first absorbent body 26 and the second absorbent body 28 may have any shape as long as they can cover the second region 12.

[0031] A DC magnetic field is applied to the first magnetic body 25 and the second magnetic body 27 by the first magnet 31 and the second magnet 32, causing a high-frequency signal passing through the metal layer 10 to propagate while being biased to one side of the propagation direction. For example, a high-frequency signal input from the first terminal T1 propagates toward the side of the metal layer 10 opposite the third terminal T3, and then propagates with low loss to the second terminal T2. On the other hand, a high-frequency signal input to the second terminal T2 propagates toward the third terminal T3 side of the metal layer 10, and then propagates to the first terminal T1. At this time, the high-frequency signal input to the second terminal T2 is absorbed by the first absorber 26 and the second absorber 28, and is therefore significantly attenuated.

[0032] The first magnetic body 25 and the second magnetic body 27 include a magnetic material. The first magnetic body 25 and the second magnetic body 27 may be a conductor or an insulator. The first magnetic body 25 and the second magnetic body 27 include, for example, a soft magnetic body. The first magnetic body 25 and the second magnetic body 27 may be, for example, a Co-based amorphous body, ferrite, Fe 85Si2B8P4Cu, Fe 86 AlB8P4Cu, Fe 78 Si9B 13 , yttrium iron garnet (YIG). YIG includes, for example, Y3Fe2(FeO4)3, Y3Fe5O 12 is.

[0033] The first magnetic body 25 and the second magnetic body 27 may be a mixture of magnetic particles and resin. The magnetic particles may include, for example, iron, silicon steel (Fe-Si), permalloy (Ni-Fe), permendur (Fe-Co), sendust (Fe-Si-Al), electromagnetic stainless steel, amorphous iron-based alloy (Fe-BC, Fe-Co), manganese zinc ferrite, nickel zinc ferrite, etc. The first magnetic body 25 and the second magnetic body 27 may be a mixture of ferrite particles and resin.

[0034] When dispersing a magnetic material in an insulating material (e.g., resin, rubber, paint, etc.), it is preferable to set the volume ratio of the magnetic material to between 10% and 70%. If the volume ratio of the magnetic material is small, the electromagnetic wave absorption capacity will be low. If the volume ratio of the magnetic material is high, it will be difficult to disperse it in the insulating material.

[0035] The first absorber 26 and the second absorber 28 include a material having a larger magnetic field loss rate than the first magnetic body 25 and the second magnetic body 27. The first absorber 26 and the second absorber 28 include, for example, any one selected from the group consisting of iron, BN, conductive carbon, SiC, and Ni-based ferrite.

[0036] The second side S2 of the first absorber 26 is a straight line. The second side S2 is the side of the first absorber 26 on the first terminal T1 and second terminal T2 side. The second side S2 intersects with a line that passes through the third terminal T3 and extends in the y direction.

[0037] The width between the first side S1 and the second side S2 is, for example, shortest width W1 at the midpoint P1 of the first side S1. The midpoint P1 is the center of the first side S1 in the x direction. Here, an example is shown in which the shortest width W1 is at the midpoint P1, but the shortest width W1 may also be at a position other than the midpoint P1.

[0038] The minimum width W1 is shorter than the width W2 between the first straight line L1 and the second straight line L2. As will be described in detail later, if the minimum width W1 is shorter than the width W2, the cutoff frequency shifts to the higher frequency side, and the isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input.

[0039] The shortest width W1 preferably satisfies, for example, the following formula (1).

[0040]

number

[0041] In equation (1), f0 is the maximum frequency of the input signal input to the first terminal T1 or the second terminal T2, ε0 is the permittivity of a vacuum, μ0 is the magnetic permeability of a vacuum, and ε eff is the effective dielectric constant of the first magnetic body 25 at frequency f0, and μ eff is the effective magnetic permeability of the first magnetic body 25 at frequency f0 when a DC magnetic field is applied from the first magnet 31 to the first magnetic body 25.

[0042] Here, the shortest width W1 between the second side S2 of the first absorber 26 and the first side S1 of the metal layer 10 has been described in detail, but it is preferable that a similar relationship be satisfied between the second side of the second absorber 28 and the first side S1 of the metal layer 10. In other words, it is preferable that the shortest width between the second side of the second absorber 28 and the first side S1 of the metal layer 10 is shorter than the width W2 between the first straight line L1 and the second straight line L2.

[0043] Furthermore, when the first loss layer 21 and the second loss layer 22 are conductors, an insulating layer is provided between the first loss layer 21 and the metal layer 10, and between the second loss layer 22 and the metal layer 10. Any known insulating layer can be used.

[0044] The first magnet 31 and the second magnet 32 ​​sandwich the metal layer 10, the first loss layer 21, and the second loss layer 22 in the z direction. The first magnet 31 and the metal layer 10 sandwich the first loss layer 21 in the z direction. The second magnet 32 ​​and the metal layer 10 sandwich the second loss layer 22 in the z direction. The first magnet 31 and the second magnet 32 ​​apply a DC magnetic field to the metal layer 10.

[0045] 5 is a plan view of the first magnet 31 and the first conductor 41 of the nonreciprocal circuit device 101 according to the first embodiment. The first magnet 31 and the second magnet 32 ​​are positioned so as to overlap the first magnetic body 25 and the second magnetic body 27 when viewed from the z direction. The first magnet 31 and the second magnet 32 ​​may also overlap the first absorber 26 and the second absorber 28 when viewed from the z direction.

[0046] The first magnet 31 and the second magnet 32 ​​are, for example, hard magnetic materials. The first magnet 31 and the second magnet 32 ​​may be insulators or conductors. The first magnet 31 and the second magnet 32 ​​include, for example, any material selected from the group consisting of insulating ferrite magnets, conductive rare earth magnets, TbFeCo, GdFeCo, SmFeCo, [Co / Pt] multilayer films, and [Co / Pd] multilayer films. If the first magnet 31 and the second magnet 32 ​​are conductors, the first conductor 41 and the second conductor 42 may be omitted.

[0047] The first conductor 41 is sandwiched between the first magnet 31 and the first loss layer 21. The second conductor 42 is sandwiched between the second magnet 32 ​​and the second loss layer 22. The first conductor 41 or the second conductor 42 is, for example, grounded to a reference potential. The reference potential is, for example, the ground. There is no particular restriction on the first conductor 41 and the second conductor 42 as long as they are conductive.

[0048] In the nonreciprocal circuit device 101 according to this embodiment, the minimum width W1 is shorter than the width W2, so that the isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input. In an edge-guided mode isolator, the lowest-order mode high-frequency signals propagate concentratedly at the edges of the metal layer 10, while the first-order and higher-order mode high-frequency signals are distributed in areas other than the edges of the metal layer 10. Therefore, the higher-order mode high-frequency signals are less likely to be absorbed than the lowest-order mode high-frequency signals. The higher-order mode high-frequency signals are generated when the width of the metal layer 10 in the direction perpendicular to the propagation direction of the high-order mode in the xy plane is approximately equal to half the wavelength of the electromagnetic wave. Therefore, by adjusting the minimum width W1, the cutoff frequency of the higher-order mode high-order mode high-frequency signals can be increased, thereby suppressing the deterioration of the isolation characteristics caused by the higher-order mode high-order mode high-order mode high-order signal.

[0049] Although an example of the first embodiment has been shown so far, the present invention is not limited to these embodiments, and various modifications are possible.

[0050] Fig. 6 is a plan view of a nonreciprocal circuit device 101A according to a first modified example. The nonreciprocal circuit device 101A according to the first modified example differs from the nonreciprocal circuit device 101 in the shape of the metal layer 10 as viewed in the z direction. In Fig. 6, components similar to those of the nonreciprocal circuit device 101 are designated by similar reference numerals, and descriptions thereof will be omitted.

[0051] The metal layer 10A has a first side S1 that curves toward the third terminal T3 from the first straight line L1, and curves toward the second straight line L2.

[0052] The non-reciprocal circuit device 101A according to the first modification has the same effect as the non-reciprocal circuit device 100 because the shortest width W1 is shorter than the width W2.

[0053] 7 is a plan view of a nonreciprocal circuit device 101B according to the second modification. The nonreciprocal circuit device 101B according to the second modification differs from the nonreciprocal circuit device 101 in the shape of the metal layer 10 as viewed in the z direction. In FIG. 7, components similar to those of the nonreciprocal circuit device 101 are designated by the same reference numerals and will not be described.

[0054] The first side S1 of the metal layer 10B is bent toward the third terminal T3 from the first straight line L1. The first side S1 of the metal layer 10B is bent toward the second straight line L2. The first side S1 of the metal layer 10B is bent multiple times.

[0055] The non-reciprocal circuit device 101B according to the second modification has the same effect as the non-reciprocal circuit device 100 because the shortest width W1 is shorter than the width W2.

[0056] 8 is a plan view of a nonreciprocal circuit device 101C according to a third modification. The nonreciprocal circuit device 101C according to the third modification differs from the nonreciprocal circuit device 101 in the shape of the metal layer 10 as viewed in the z direction. In FIG. 8, components similar to those of the nonreciprocal circuit device 101 are designated by the same reference numerals and will not be described.

[0057] The first side S1 of the metal layer 10C is curved toward the third terminal T3 from the first straight line L1. The first side S1 of the metal layer 10C is bent toward the second straight line L2. The first side S1 of the metal layer 10C is bent multiple times. The distance between the first side S1 and the second side S2 may be the shortest width W1 at multiple points.

[0058] The non-reciprocal circuit device 101C according to the third modification has the same effect as the non-reciprocal circuit device 100 because the shortest width W1 is shorter than the width W2.

[0059] 9 is a cross-sectional view of a nonreciprocal circuit device 101D according to a fourth modification. The nonreciprocal circuit device 101C according to the fourth modification differs from the nonreciprocal circuit device 101 in that it includes a resistor 50. In FIG. 9, the same components as those in the nonreciprocal circuit device 101 are denoted by the same reference numerals, and description thereof will be omitted.

[0060] In the non-reciprocal circuit device 101, the third terminal T3 is an open end, but as shown in FIG. 9, the third terminal T3 may be connected to a resistor 50. By providing the resistor 50, it is possible to further improve the absorption characteristics of high-frequency signals at the third terminal T3. Furthermore, a ground conductor may be provided instead of the resistor 50. The ground conductor electrically connects the first conductor 41, the metal layer 10, and the second conductor 42, and grounds the metal layer 10.

[0061] The non-reciprocal circuit device 101D according to the fourth modification has the same effect as the non-reciprocal circuit device 100 because the shortest width W1 is shorter than the width W2.

[0062] "Second embodiment" 10 is a cross-sectional view of a nonreciprocal circuit device 102 according to the second embodiment. The nonreciprocal circuit device 102 includes, for example, a metal layer 60, a first loss layer 71, a second loss layer 72, a first magnet 31, a second magnet 32, a first conductor 41, and a second conductor 42. The nonreciprocal circuit device 102 functions as, for example, an isolator. The first magnet 31, the second magnet 32, the first conductor 41, and the second conductor 42 are similar to those of the nonreciprocal circuit device 101 according to the first embodiment.

[0063] Fig. 11 is a plan view of the metal layer 60 and the first loss layer 71 of the nonreciprocal circuit element 102 according to the second embodiment. Fig. 10 is a cross section taken along line AA in Fig. 11. Fig. 12 is a plan view of the metal layer 60 of the nonreciprocal circuit element 102 according to the second embodiment. Fig. 13 is a plan view of the first loss layer 71 of the nonreciprocal circuit element 102 according to the second embodiment.

[0064] The configuration of the metal layer 60 is similar to that of the metal layer 10. The metal layer 60 is made of the same material as the metal layer 10. The metal layer 60 has a first terminal T1, a second terminal T2, and a third terminal T3. The metal layer 60 has a first region 61 and a second region 62. The first region 61 extends between the first terminal T1 and the second terminal T2. The first region 61 overlaps with the first magnetic body 25 in the z direction. The second region 62 extends between the first terminal T1 and the third terminal T3 and between the second terminal T2 and the third terminal. The second region 62 overlaps with the first absorber 26 in the z direction.

[0065] The first side S1' connecting the first terminal T1 and the second terminal T2 of the metal layer 60 is a straight line that does not bend. The first side S1' is a straight line that extends along the first straight line L1'. The first straight line L1' is a straight line that connects the first end S1'A ​​and the second end S1'B of the first side S1'.

[0066] The first loss layer 71 and the second loss layer 72 sandwich the metal layer 60 in the z direction. The first loss layer 71 includes a first magnetic body 75 and a first absorber 76. The second loss layer 72 includes a second magnetic body 77 and a second absorber 78. The first loss layer 71 and the second loss layer 72 have substantially the same shapes. The first loss layer 71 is similar to the first loss layer 21 in terms of material and configuration, except for the shape of the second side S2. The second loss layer 72 is similar to the second loss layer 22 in terms of material and configuration, except for the shape of the second side S2.

[0067] The second side S2' of the first absorber 76 is bent toward the first terminal T1 and the second terminal T2 from the second straight line L2'. The second side S2' is bent toward the first straight line L1'. The second straight line L2' is a straight line connecting the first end S2'A and the second end S2'B of the second side S2'.

[0068] The width between the first side S1' and the second side S2' is, for example, shortest width W1 at midpoint P1' of the second side S2'. Midpoint P1' is the center of the second side S2' in the x-direction. Here, an example is shown in which shortest width W1 is at midpoint P1', but shortest width W1 may also be at a position other than midpoint P1'.

[0069] The minimum width W1 is shorter than the width W2 between the first straight line L1' and the second straight line L2'. If the minimum width W1 is shorter than the width W2, the cutoff frequency shifts to the higher frequency side, and the isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input. It is preferable that the minimum width W1 satisfies, for example, the above-mentioned formula (1).

[0070] Here, we have explained in detail the shortest width W1 between the second side S2' of the first absorber 76 and the first side S1' of the metal layer 60, but it is preferable that a similar relationship be satisfied between the second side of the second absorber 78 and the first side S1' of the metal layer 60.

[0071] In the non-reciprocal circuit device 102 according to this embodiment, the shortest width W1 is shorter than the width W2, and therefore the isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input.

[0072] Although an example of the second embodiment has been shown so far, the present invention is not limited to these embodiments, and various modifications are possible.

[0073] Fig. 14 is a plan view of a nonreciprocal circuit device 102A according to a fifth modified example, Fig. 15 is a plan view of a nonreciprocal circuit device 102B according to a sixth modified example, and Fig. 16 is a plan view of a nonreciprocal circuit device 102C according to a seventh modified example.

[0074] Similar to the shape of the first side S1 in the first to third modified examples of the first embodiment, the shape of the second side S2' in the first embodiment is also arbitrary. For example, as shown in FIG. 14, the second side S2' may be curved toward the first straight line L1'. Furthermore, as shown in FIGS. 15 and 16, the second side S2' may be bent multiple times toward the first straight line L1'. Furthermore, as shown in FIG. 16, the distance between the first side S1' and the second side S2' may be the shortest width W1 at multiple points.

[0075] Each of the non-reciprocal circuit devices 102A, 102B, and 102C according to the fifth to seventh modifications has the shortest width W1 shorter than the width W2, and therefore has the same effect as the non-reciprocal circuit device 100.

[0076] In the second embodiment and its modified examples, the third terminal T3 may also be an open end, connected to a resistor, or connected to a ground conductor.

[0077] "Third embodiment" Fig. 17 is a cross-sectional view of the non-reciprocal circuit device 103 according to the third embodiment. Fig. 18 is a plan view of the non-reciprocal circuit device 103 according to the third embodiment.

[0078] The non-reciprocal circuit element 103 includes, for example, a metal layer 10, a first loss layer 71, a second loss layer 72, a first magnet 31, a second magnet 32, a first conductor 41, and a second conductor 42. The non-reciprocal circuit element 103 functions as, for example, an isolator. In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

[0079] The non-reciprocal circuit device 103 according to the third embodiment is a combination of the metal layer 10 according to the first embodiment and the first loss layer 71 and second loss layer 72 according to the second embodiment.

[0080] The first side S1 of the metal layer 10 is bent toward the third terminal T3 side from the first straight line L1. The first side S1 is bent toward the second straight line L2'. The second side S2' of the first absorber 76 is bent toward the first terminal T1 and second terminal T2 side from the second straight line L2'. The second side S2' is bent toward the first straight line L1.

[0081] The minimum width W1 is shorter than the width W2 between the first straight line L1 and the second straight line L2'. If the minimum width W1 is shorter than the width W2, the cutoff frequency shifts to the higher frequency side, and the isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input. It is preferable that the minimum width W1 satisfies, for example, the above-mentioned formula (1).

[0082] In the non-reciprocal circuit device 103 according to this embodiment, the minimum width W1 is shorter than the width W2, so that the isolation characteristics are less likely to deteriorate even when a high-frequency input signal is input. Furthermore, the non-reciprocal circuit device 103 may be a combination of the modified examples of the first and second embodiments. [Example]

[0083] Example 1 In Example 1, a non-reciprocal circuit device having the same configuration as an example of the first embodiment (FIG. 6) was fabricated. The first side S1 of the metal layer 10 was curved toward the third terminal T3 side from the first straight line L1. The second sides S2 of the first absorber 26 and the second absorber 28 were straight. The width between the first side S1 and the second side S2 was, for example, shortest width W1 at the midpoint P1 of the first side S1, and this shortest width W1 was shorter than the width W2 between the first straight line L1 and the second straight line L2. The isolation characteristics of the non-reciprocal circuit device of Example 1 versus frequency were determined by simulation.

[0084] Example 2 In Example 2, a non-reciprocal circuit device was fabricated with a configuration similar to that of an example of the second embodiment (FIG. 14). The first side S1' of the metal layer 60 was a straight line extending along the first straight line L1'. The second sides S2' of the first absorber 76 and the second absorber 78 were curved toward the first straight line L1'. The width between the first side S1' and the second side S2' was, for example, a shortest width W1 at the midpoint P1' of the second side S2', and this shortest width W1 was shorter than the width W2 between the first straight line L1' and the second straight line L2'. The isolation characteristics of the non-reciprocal circuit device of Example 1 versus frequency were determined by simulation.

[0085] (Comparative Example 1) The non-reciprocal circuit device of Comparative Example 1 differs from Example 1 in that the first side S1 of the metal layer 10 is a straight line extending along the first straight line L1, and differs from Example 2 in that the second sides S2' of the first absorber 76 and the second absorber 78 are straight lines extending along the second straight line L2'. The first side S1 and the second side S2 are parallel to each other, and the widths of the first side S1 and the second side S2 are constant. In other words, the width W2 of the first side S1 and the second side S2 is equal to the shortest width W1. The isolation characteristics of the non-reciprocal circuit device of Comparative Example 1 versus frequency were determined by simulation.

[0086] FIG. 19 shows the measurement results of the isolation characteristics of the non-reciprocal circuit devices according to Example 1, Example 2, and Comparative Example 1. The horizontal axis of FIG. 19 represents the frequency of the high-frequency signal input to the first terminal T1, and the vertical axis represents the isolation characteristics. As shown in FIG. 19, in Comparative Example 1, the isolation characteristics begin to deteriorate at 7.5 GHz or higher. In contrast, in Examples 1 and 2, the isolation characteristics do not begin to deteriorate until around 8.0 GHz. In other words, the point at which the isolation characteristics begin to deteriorate is shifted to the higher frequency side. Compared to Comparative Example 1, Examples 1 and 2 are less likely to deteriorate in isolation characteristics even when a high-frequency input signal is input. [Explanation of symbols]

[0087] 10, 10A, 10B, 10C...metal layer, 11, 61...first region, 12, 62...second region, 21, 71...first loss layer, 22, 72...second loss layer, 25, 75...first magnetic body, 26, 76...first absorber, 27, 77...second magnetic body, 28, 78...second absorber, 31...first magnet, 32...second magnet, 41...first conductor, 42...second conductor, 50...resistor, 60 ...metal layer, 100, 101, 101A, 101B, 101C, 101D, 102, 102A, 102B, 102C, 103...non-reciprocal circuit element, L1, L1'...first straight line, L2, L2'...second straight line, P1, P1'...midpoint, S1, S1'...first side, S2, S2'...second side, T1...first terminal, T2...second terminal, T3...third terminal, W1...shortest width, W2...width

Claims

1. a metal layer, a lossy layer, and a magnet; the metal layer includes a first terminal, a second terminal, and a third terminal; the lossy layer includes a magnetic material and an absorber; the magnetic body overlaps the first region of the metal layer in a thickness direction; the absorber overlaps the second region of the metal layer in the thickness direction; the first region extends across the first terminal and the second terminal; the second region extends between the first terminal and the third terminal and between the second terminal and the third terminal; the magnet and the metal layer sandwich at least the magnetic body in the thickness direction; When viewed from the thickness direction, the shortest width between a first side connecting the first terminal and the second terminal of the metal layer and a second side of the absorber on the first terminal and second terminal side is a non-reciprocal circuit element having a length shorter than the width between a first straight line connecting both ends of the first side and a second straight line connecting both ends of the second side;

2. The non-reciprocal circuit device according to claim 1 , wherein the width between the first side and the second side is shortest at the midpoint of the first side.

3. The non-reciprocal circuit device according to claim 1 , wherein the first side is bent or curved toward the second straight line.

4. The non-reciprocal circuit device according to claim 1 , wherein the second side is bent or curved toward the first straight line.

5. the first side is bent or curved toward the second straight line, The non-reciprocal circuit device according to claim 1 , wherein the second side is bent or curved toward the first straight line.

6. The shortest width satisfies the following formula (1): [Equation 1] In the formula (1), W1 is the shortest width, and f ０ is the maximum frequency of the input signal input to the first terminal or the second terminal, and ε ０ is the dielectric constant of a vacuum, and μ ０ is the permeability of a vacuum, and ε ｅｆｆ is the frequency f ０ is the effective dielectric constant of the magnetic material at μ ｅｆｆ is the frequency f when a DC magnetic field is applied to the magnetic body from the magnet. ０ 2. The nonreciprocal circuit device according to claim 1, wherein the effective permeability of the magnetic material is

7. 2. The non-reciprocal circuit device according to claim 1, wherein the third terminal is grounded directly or via a resistor.

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