WO2018020801A1

WO2018020801A1 - Irreversible circuit element, irreversible circuit module, front-end circuit and communication device

Info

Publication number: WO2018020801A1
Application number: PCT/JP2017/019264
Authority: WO
Inventors: 岡嶋　伸吾
Original assignee: 株式会社村田製作所
Priority date: 2016-07-29
Filing date: 2017-05-23
Publication date: 2018-02-01

Abstract

An irreversible circuit element (1) is mounted on a surface (50a) of a mounting board (50). The irreversible circuit element (1) is provided with a permanent magnet (30), a ferrite (40), and a first yoke (10) provided between the ferrite (40) and the mounting board (50). The ferrite (40) comprises a central conductor part (41) formed on one principal surface (40a), and an extraction conductor part (42) extracted from the central conductor part (41), the central conductor part (41) has an LC component, the first yoke (10) comprises an input/output conductor part (11) connected to the extraction conductor part (42), and a ground conductor part (12) disposed close to the input/output conductor part (11) with a predetermined space (i1) therebetween, the ground conductor part (12) is connected to a ground pattern (52), the input/output conductor part (11) is connected to a transmission line pattern (51), and a millimeter-waveband high-frequency signal is inputted to and outputted from the input/output conductor part (11) via the transmission line pattern (51).

Description

Non-reciprocal circuit element, non-reciprocal circuit module, front-end circuit and communication device

The present invention relates to a nonreciprocal circuit element, a nonreciprocal circuit module including the nonreciprocal circuit element, a front-end circuit, and a communication device.

Non-reciprocal circuit elements such as isolators and circulators have a characteristic of allowing signals to pass only in a predetermined specific direction and not substantially passing in the reverse direction. As such an irreversible circuit element, a configuration using the irreversibility of ferrite is known (see, for example, Patent Document 1).

The non-reciprocal circuit element described in Patent Document 1 has a structure in which a multilayer substrate, ferrite, a center electrode, and a magnet are stacked in order from the inner bottom of the case, and a cap is put on the upper side of the case. Input / output terminals are provided on the lower side of the case, and the input / output terminals are connected to the lower surface electrode of the multilayer substrate. The lower surface electrode of the multilayer substrate is connected to the center electrode via the circuit element inside the multilayer substrate, the upper surface electrode of the multilayer substrate, and the lower surface electrode of ferrite.

In this nonreciprocal circuit element, a signal input from an input / output terminal is transmitted to the central electrode via these electrodes and circuit elements, and transmission of a signal using the nonreciprocal nature of the ferrite is performed at the central electrode. Done. Thereby, the signal is allowed to pass only in a predetermined specific direction.

JP 2005-20195 A

The non-reciprocal circuit element described in Patent Document 1 is surface-mounted on a mounting board, and a signal is input from a transmission line pattern on the mounting board via an input / output terminal. A central electrode constituting the L component and a multilayer substrate constituting the C component are separately formed. Since the L component and the C component are separately formed, a part of the step is increased in the line from the transmission line pattern to the center electrode. That is, in the nonreciprocal circuit device and the mounting substrate, the bent part of the transmission line increases in the line from the transmission line pattern to the center electrode.

Since the nonreciprocal circuit element is assumed to be used in a microwave band such as 1 GHz to 2 GHz band, there is little problem even if there is a step or a bent part of the transmission line, but in a millimeter wave band of 20 GHz or more, There is a problem in that power radiation occurs in a bent structure such as a step or a bent portion of the transmission line, resulting in a large radiation loss. When the radiation loss is large, unnecessary electromagnetic waves are radiated and the power consumption of the nonreciprocal circuit element is increased.

Therefore, the present invention is surface-mounted on a mounting substrate, which can reduce a transmission signal radiation loss caused by a bent structure of a transmission line in a line extending from the transmission line pattern to the center electrode in a millimeter wave band of 20 GHz or more. An object is to provide a nonreciprocal circuit element or the like.

In order to achieve the above object, a non-reciprocal circuit device according to an aspect of the present invention is a non-reciprocal circuit device mounted on a surface of a mounting substrate, and a DC magnetic field is applied by the permanent magnet. And a first yoke provided between the ferrite and the mounting substrate, and the ferrite is formed on one main surface facing away from a surface located on the first yoke side. A central conductor part, and a lead conductor part connected to the central conductor part and led out from the central conductor part, the central conductor part has an LC component, and the first yoke has the An input / output conductor connected to the lead conductor and a ground conductor disposed adjacent to the input / output conductor at a predetermined interval, and the ground conductor is formed on the surface of the mounting substrate. Along the shape The input / output conductor portion is connected to a transmission line pattern formed along the surface of the mounting substrate, and the input / output conductor portion is connected to the ground via the transmission line pattern. A high frequency signal in a wave band is input / output.

According to this, since the ground conductor part of the non-reciprocal circuit element that is surface-mounted on the mounting substrate is disposed close to the input / output conductor part, the transmission line pattern reaches the central conductor part via the input / output conductor part. The radiation loss of the transmission signal caused by the bent structure of the transmission line in the line can be reduced.

Further, the central conductor portion may be circular.

According to this, even when the central conductor portion is composed of a circular distributed constant type circuit and the nonreciprocal circuit element is adapted to the millimeter wave band (20 GHz or more), the transmission line is bent. The radiation loss of the generated transmission signal can be reduced.

Further, a cylindrical second yoke that covers the permanent magnet and the ferrite may be provided, and the second yoke may be connected to the ground conductor portion of the first yoke.

Thus, by covering the permanent magnet and the ferrite with the second yoke connected to the ground and electromagnetically shielding them, the electromagnetic waves radiated from the ferrite can be suppressed and the electrical characteristics of the nonreciprocal circuit element can be improved.

Further, the ferrite and the first yoke may be in contact with each other.

In this way, the ferrite and the first yoke are in contact with each other, and the multi-layer substrate having the C component is not sandwiched between them as in the prior art, so the line length from the input / output conductor portion to the central conductor portion is shortened. And radiation loss of the transmission signal can be reduced. Moreover, the nonreciprocal circuit element 1 can be reduced in height.

Further, the non-reciprocal circuit element may have three lead conductor portions and three input / output conductor portions.

According to this, it is possible to provide a three-port non-reciprocal circuit device in which the transmission signal radiation loss is reduced.

A nonreciprocal circuit module according to an aspect of the present invention includes the nonreciprocal circuit element and a mounting board on which the nonreciprocal circuit element is mounted. The mounting board extends along a surface of the mounting board. A transmission line pattern formed in a close proximity to the transmission line pattern and spaced from the ground pattern, and the input / output conductor portion of the non-reciprocal circuit element is connected to the transmission line pattern. The ground conductor portions of the nonreciprocal circuit elements are connected to the ground pattern.

As described above, when the nonreciprocal circuit element is mounted on the mounting substrate and a transmission signal is input from the transmission line pattern on the mounting substrate, power is radiated in a bent region that bends in a direction perpendicular to the direction in which the transmission line pattern extends. However, since the ground conductor portion is arranged close to the input / output conductor portion, radiation loss in the bent region can be reduced.

In addition, when the wavelength of the high-frequency signal input / output to / from the input / output conductor via the transmission line pattern is λ, the input / output conductor and the ground conductor in the signal propagation direction of the transmission line pattern The predetermined interval may be greater than 0 and not greater than 0.1λ.

Thus, by setting the predetermined distance between the input / output conductor portion and the ground conductor portion to be 0.1λ or less, radiation loss in the input / output conductor portion can be reduced.

Further, the total radiation loss generated in the input / output conductor part and the lead conductor part may be within 30% of the electric power input to the input / output conductor part via the transmission line pattern.

According to this, radiation loss in the input / output conductor can be reduced.

Further, the present invention can be realized not only as the above-described non-reciprocal circuit element but also as a front-end circuit including the non-reciprocal circuit element. That is, in order to achieve the above object, a front end circuit according to an aspect of the present invention includes the non-reciprocal circuit element, a transmission-side circuit connected to one of the three input / output conductors, A receiving circuit connected to an input / output conductor different from the input / output conductor connected to the transmitting circuit, and one of the three input / output conductors; and the three input / output conductors And an antenna terminal connected to an input / output conductor portion different from the input / output conductor portions connected to the transmission side circuit and the reception side circuit.

According to such a front-end circuit, it is possible to realize a desired pass characteristic by providing the non-reciprocal circuit element with reduced radiation loss.

Furthermore, the present invention can be realized not only as the above-described front end circuit but also as a communication device including the front end circuit. In other words, in order to achieve the above object, a communication device according to one aspect of the present invention includes a signal processing circuit that processes a high-frequency signal and the front end circuit.

According to such a communication apparatus, it is possible to improve communication quality by including the nonreciprocal circuit element with reduced radiation loss.

The nonreciprocal circuit device or the like of the present invention is surface-mounted on a mounting substrate, and can reduce a transmission signal radiation loss in a millimeter wave band of 20 GHz or more.

1 is a perspective view of a nonreciprocal circuit device and a nonreciprocal circuit module according to Embodiment 1. FIG. FIG. 2 is an exploded perspective view of the nonreciprocal circuit device and the nonreciprocal circuit module according to Embodiment 1. FIG. 3 is an enlarged view of a portion III of the nonreciprocal circuit module shown in FIG. 4A is a cross-sectional view of the non-reciprocal circuit device shown in FIG. 1 taken along the line IVA-IVA. 4B is a cross-sectional view of the non-reciprocal circuit device shown in FIG. 1 taken along the line IVB-IVB. FIG. 5 is a cross-sectional plan view of the non-reciprocal circuit device shown in FIG. 4A taken along line VV. 6A is a cross-sectional view of the non-reciprocal circuit module shown in FIG. 1 taken along the line IVA-IVA. 6B is a diagram illustrating an example of a power transmission path of the non-reciprocal circuit module illustrated in FIG. 6A. FIG. 7A is a perspective view showing a transmission line model related to the first embodiment. FIG. 7B is a cross-sectional view of FIG. 7A taken along the XZ plane. FIG. 8A is a graph showing the relationship between the distance between the input / output conductor part and the ground conductor and the S parameter in the transmission line model shown in FIG. 7A. FIG. 8B is a graph showing the relationship between the distance between the input / output conductor part and the ground conductor part and the radiation loss in the transmission line model shown in FIG. 7A. FIG. 9 is a cross-sectional view showing the nonreciprocal circuit device according to the second embodiment. FIG. 10 is a functional block diagram illustrating a communication apparatus according to the third embodiment.

Hereinafter, a nonreciprocal circuit element, a nonreciprocal circuit module, a front end circuit, and a communication device according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily shown strictly. Moreover, in each figure, the same code | symbol is attached | subjected to the substantially same structure, The overlapping description may be abbreviate | omitted or simplified. In the following description, the top view may be hatched for simplicity.

(Embodiment 1)
The nonreciprocal circuit device according to Embodiment 1 is mounted on, for example, a mobile phone base station, passes a transmission signal from a transmission side circuit to an antenna, and passes a reception signal received by the antenna to a reception circuit. Let That is, the non-reciprocal circuit element has a characteristic that allows a signal to pass only in a predetermined specific direction and does not substantially pass the reverse direction. The nonreciprocal circuit device according to the present embodiment is used, for example, in a millimeter wave band (20 GHz or more).

[1.1 Non-reciprocal circuit elements and non-reciprocal circuit module configurations]
FIG. 1 is a perspective view of the nonreciprocal circuit device 1 and the nonreciprocal circuit module 2 according to Embodiment 1. FIG. FIG. 2 is an exploded perspective view of the nonreciprocal circuit device 1 and the nonreciprocal circuit module 2. FIG. 3 is an enlarged view of a portion III of the non-reciprocal circuit module 2 shown in FIG. 4A is a cross-sectional view of the nonreciprocal circuit device 1 shown in FIG. 1 taken along the line IVA-IVA. 4B is a cross-sectional view of the non-reciprocal circuit device 1 shown in FIG. 2 taken along the line IVB-IVB. FIG. 5 is a plan cross-sectional view of the nonreciprocal circuit device 1 shown in FIG. 4A taken along line VV.

1 to 3, the nonreciprocal circuit module 2 includes a nonreciprocal circuit element 1 and a mounting substrate 50 on which the nonreciprocal circuit element 1 is mounted.

First, the configuration of the nonreciprocal circuit element 1 will be described.

The nonreciprocal circuit device 1 includes a first yoke 10 serving as a base material, a ferrite 40 having a central conductor portion 41, a permanent magnet 30, and a second yoke 20. A ferrite 40 is disposed on the first yoke 10, and a permanent magnet 30 is disposed on the ferrite 40. The ferrite 40 and the permanent magnet 30 are covered with the cylindrical second yoke 20.

The second yoke 20 has a top surface portion 21 and a side surface portion 22, and the lower side of the side surface portion 22 is fixed to the first yoke 10 by welding or soldering. The second yoke 20, together with the first yoke 10, applies a magnetic shunting action to the magnetic field formed by the permanent magnet 30, and electromagnetically shields the permanent magnet 30 and the ferrite 40. As a material of the second yoke 20, for example, iron (Fe) is used. Silver plating may be applied to the surface of the second yoke 20.

The permanent magnet 30 has a flat plate shape and is arranged to apply a DC magnetic field to the ferrite 40. Specifically, the permanent magnet 30 is disposed on the ferrite 40 and is in contact with the central conductor portion 41 formed on the ferrite 40.

The ferrite 40 is a magnetic member, and for example, a material containing iron oxide as a main component and containing at least one of zinc, nickel, and copper is used.

The ferrite 40 has a flat plate shape and has one main surface 40a, the other main surface 40b facing away from the one main surface 40a, and a side surface 40c. In other words, the one main surface 40a faces away from the surface (the other main surface 40b) located on the first yoke 10 side. The thickness of the ferrite 40 is, for example, 0.15 mm.

As shown in FIG. 2, the ferrite 40 is formed with a central conductor portion 41 and three lead conductor portions 42 connected to the central conductor portion 41. As the material of the center conductor portion 41 and the lead conductor portion 42, for example, a metal or alloy mainly containing silver is used.

The central conductor portion 41 has a circular shape and is formed on one main surface 40 a of the ferrite 40. The center conductor portion 41 is a distributed constant type resonator and has an LC component.

Each of the three lead conductor portions 42 has a line shape, and is drawn from the central conductor portion 41 to the other main surface 40b side. Specifically, as shown in FIG. 3, each of the lead conductor portions 42 has a main surface lead portion 42 a formed on one main surface 40 a and a penetration connecting the main surface lead portion 42 a and the other main surface 40 b side. And a drawer portion 42b.

One end of the main surface leading portion 42a is connected to the outer edge of the circular central conductor portion 41, respectively. The angular interval between adjacent main surface leading portions 42a is an equal angle (120 ° in the present embodiment). The other end of the main surface lead portion 42a extends toward the outer edge of the one main surface 40a of the ferrite 40 and is connected to one end of the through lead portion 42b. The through-drawing portion 42b is drawn linearly from the one main surface 40a side toward the other main surface 40b side. In the present embodiment, the propagation direction of the signal transmitted through the penetration lead portion 42b is perpendicular to the one main surface 40a and the other main surface 40b (parallel to the thickness direction of the ferrite 40).

Note that the through lead-out portion 42b may be a via conductor that penetrates the one main surface 40a and the other main surface 40b, or may be a side conductor formed along the side surface 40c of the ferrite 40. Further, a wide impedance adjustment portion 42c may be provided in a part of the main surface lead portion 42a.

The first yoke 10 has a flat plate shape as shown in FIGS. 2 to 5, and has a first main surface 10a and a second main surface 10b facing away from the first main surface 10a. The first yoke 10 is disposed such that the first main surface 10 a is in contact with the other main surface 40 b of the ferrite 40. The first yoke 10 is provided between the ferrite 40 and the mounting substrate 50. The thickness of the first yoke 10 is, for example, 0.1 mm.

As shown in FIG. 5, the first yoke 10 includes three input / output conductor portions 11 and a ground conductor portion 12 that is disposed close to each of the input / output conductor portions 11 with a predetermined interval i1. Yes. The input / output conductor portion 11 is a portion where high-frequency signals in the millimeter wave band are input / output via a transmission line pattern described later, and the ground conductor portion 12 is a portion grounded to a reference potential. An insulating part 13 is provided between the input / output conductor part 11 and the ground conductor part 12.

As the material of the input / output conductor 11 and the ground conductor 12, for example, iron (Fe) is used. In order to improve electrical characteristics, the exposed surfaces of the input / output conductor portion 11 and the ground conductor portion 12 may be subjected to silver plating.

The ground conductor portion 12 occupies most of the first yoke 10 (for example, 80% or more and 97% or less) and applies a magnetic shunting action to the magnetic field together with the second yoke 20. The ground conductor portion 12 is formed so as to penetrate between the first main surface 10a and the second main surface 10b. Further, the ground conductor portion 12 is disposed close to the input / output conductor portion 11 in the direction along the first main surface 10a in order to reduce radiation loss of signals input to the input / output conductor portion 11. Specifically, at least a part of the ground conductor portion 12 is close to the input / output conductor portion 11 with a predetermined interval i1 (0 <i1 ≦ λ / 4, where λ is a wavelength in the millimeter wave band). Has been placed. A more desirable value of the predetermined interval i1 will be described later.

The ground conductor portion 12 is joined to the other main surface 40b of the ferrite 40 using, for example, an adhesive (not shown).

The three input / output conductor portions 11 correspond to the three lead conductor portions 42 and are connected to the other end of the through lead portion 42b of the lead conductor portion 42 using solder or the like (not shown).

As shown in FIG. 3 and FIG. 4A, the input / output conductor portion 11 is formed so as to penetrate linearly between the first main surface 10a and the second main surface 10b. In the present embodiment, the propagation direction of the signal transmitted through the input / output conductor portion 11 is perpendicular to the first main surface 10a and the second main surface 10b (parallel to the thickness direction of the first yoke 10). That is, the input / output conductor portion 11 and the through lead-out portion 42b connect the second main surface 10b of the first yoke 10 and the one main surface 40a of the ferrite 40 with the shortest distance.

In addition, the line cross-sectional area of the input / output conductor 11 is the same as the line cross-sectional area of the through lead-out part 42b. The input / output conductor portion 11 may be formed along the side surface of the first yoke 10 as long as it is directly below the through-drawing portion 42b.

As shown in FIGS. 4A and 5, three insulating portions 13 are provided so as to cover the side surface 11 a of the input / output conductor portion 11 with each of the three input / output conductor portions 11 as a core material. The ground conductor portion 12 is further provided so as to cover the side surface 13a of the insulating portion 13. That is, the insulating portion 13 is provided between the input / output conductor portion 11 and the ground conductor portion 12. The thickness of the insulating portion 13 existing between the input / output conductor portion 11 and the ground conductor portion 12 is a predetermined interval i1 between the input / output conductor portion 11 and the ground conductor portion 12. The insulating portion 13 does not have to be provided on all the side surfaces 11a of the input / output conductor portion 11, and at least the ground conductor portion 12 can support the input / output conductor portion 11 via the insulating portion 13. What is necessary is just to be formed between the one part side surface 11a of the input / output conductor part 11, and the ground conductor part 12. FIG.

As a material of the insulating part 13, for example, an epoxy resin is used. The first yoke 10 is formed, for example, by integrally molding the insulating portion 13, the input / output conductor portion 11, and the ground conductor portion 12 and then slicing.

Further, the first yoke 10 is provided with an input / output terminal 16 and a ground terminal 17 in order to improve electrical and mechanical connectivity with the mounting substrate 50. Three input / output terminals 16 are provided corresponding to each of the three input / output conductor portions 11. Each of the input / output terminals 16 is formed on the second main surface 10 b so as not to be connected to the ground conductor portion 12 but to be connected to the corresponding input / output conductor portion 11. The ground terminal 17 is provided in contact with the ground conductor portion 12. As a material of the input / output terminal 16 and the ground terminal 17, for example, silver or nickel is used.

The non-reciprocal circuit element 1 is mounted on the surface of the mounting substrate 50 from the input / output terminal 16 and the ground terminal 17 using solder or the like. The input / output terminal 16 and the ground terminal 17 are not necessarily required. For example, the input / output conductor portion 11 and the ground conductor portion 12 may be connected to the mounting substrate 50 using solder or the like without providing the input / output terminal 16 and the ground terminal 17.

Next, the nonreciprocal circuit module 2 will be described. The nonreciprocal circuit module 2 has a structure in which the nonreciprocal circuit element 1 is mounted on the surface of the mounting substrate 50.

The mounting substrate 50 has a transmission line pattern 51 and a ground pattern 52 formed along the surface 50a, as shown in FIG. Three transmission line patterns 51 are provided on the surface 50 a of the mounting substrate 50 corresponding to the three input / output conductor portions 11 of the nonreciprocal circuit element 1. The ground pattern 52 is disposed close to the transmission line pattern 51 at an interval in a region other than the transmission line pattern 51. The mounting board 50 also has a ground pattern on the back surface facing away from the front surface 50a (not shown). The ground pattern 52 on the front surface 50a and the ground pattern on the back surface are connected to each other by a plurality of via conductors (not shown). The substrate body of the mounting substrate 50 is formed of a ceramic material or an organic material. The transmission line pattern 51 and the ground pattern 52 are formed of a conductor material whose main component is copper.

FIG. 6A is a cross-sectional view of the non-reciprocal circuit module 2 shown in FIG. 1 taken along the line IVA-IVA.

As shown in FIG. 6A, the input / output conductor 11 of the non-reciprocal circuit element 1 is connected to the transmission line pattern 51 of the mounting substrate 50 via the input / output terminals 16 and solder (not shown). The ground conductor portion 12 of the nonreciprocal circuit element 1 is connected to the ground pattern 52 of the mounting substrate 50 via the ground terminal 17 and solder (not shown). Specifically, a region on the second main surface 10 b side of the input / output conductor portion 11 is connected to the transmission line pattern 51, and a region on the second main surface 10 b side of the ground conductor portion 12 is connected to the ground pattern 52. With this mounting structure, a high-frequency signal is input to the nonreciprocal circuit element 1 and the nonreciprocal circuit element 1 is electromagnetically shielded.

In FIG. 6A, the permanent magnet 30 is disposed below the cylindrical second yoke 20, but the permanent magnet 30 may be disposed above the cylindrical second yoke 20. As a result, the permanent magnet 30 is located outside the second yoke 20, so it is not necessary to have a size that fits into the second yoke 20, and can be a magnet having a larger volume than the second yoke 20. The magnetic force applied to the ferrite 40 can be increased by increasing the size of the permanent magnet 30. At this time, for the purpose of suppressing radiation, the second yoke 20 may be an RF shield having no magnetic permeability such as copper.

Here, the power transmission path in the nonreciprocal circuit device 1 will be described. 6B is a diagram illustrating an example of a power transmission path of the irreversible circuit module 2 illustrated in FIG. 6A.

In the nonreciprocal circuit element 1, signal transmission using the irreversibility of the ferrite 40 is performed in the central conductor portion 41. In order to send a signal to the central conductor 41, it is necessary to transmit power from the transmission line pattern 51 to the central conductor 41 via the input / output terminal 16, the input / output conductor 11, and the lead conductor 42. .

Here, since the central conductor portion 41 is disposed at a position higher than the transmission line pattern 51, the power transmission path T1 is in the direction in which the transmission line pattern 51 extends (on the surface 50a) as shown by the arrows in FIG. 6B. A bent region HA that is bent in a direction perpendicular to the transmission line pattern 51 (a direction perpendicular to the surface 50a). For this reason, the transmission line has a structure in which the radiation loss of electric power becomes large in the bent region HA. However, in the present embodiment, the ground conductor portion 12 is provided in the vicinity of the input / output conductor portion 11 located in the bent area HA. Specifically, in the signal propagation direction of the transmission line pattern 51, the ground conductor portion 12 is arranged with a small interval i1 of λ / 4 or less with respect to the input / output conductor portion 11. Thereby, the radiation loss of the electric power in the bending area | region HA can be reduced.

Further, in the nonreciprocal circuit element 1, since the input / output conductor portion 11 and the through lead-out portion 42b are connected in a straight line, the second main surface 10b of the first yoke 10 and the one main portion of the ferrite 40 are compared with the prior art. It is possible to reduce radiation loss of signals transmitted between the surfaces 40a.

Further, in the nonreciprocal circuit element 1, the other main surface 40b of the ferrite 40 and the first main surface 10a of the first yoke 10 are in contact with each other, and a multilayer substrate having a C component as shown in the prior art is interposed therebetween. It is not caught. With this structure, the line length from the input / output conductor portion 11 to the central conductor portion 41 is shortened, and the radiation loss of the transmission signal can be reduced. Moreover, the nonreciprocal circuit element 1 can be reduced in height.

[1.2 Simulation of transmission line]
Next, a transmission line simulation related to the nonreciprocal circuit device 1 will be described. This simulation shows the radiation loss of power when the distance i1 between the input / output conductor part and the ground conductor part is changed.

FIG. 7A is a perspective view showing a transmission line model 90. FIG. FIG. 7B is a cross-sectional view of FIG. 7A taken along the XZ plane. The transmission line model 90 shown in FIGS. 7A and 7B has substantially the same configuration as the transmission line of the nonreciprocal circuit element 1 except for the central conductor portion and the input / output terminals.

In this transmission line model 90, two

transmission line patterns

92 a and 92 b are provided on the main surface of the mounting substrate 91. Between the two

transmission line patterns

92a and 92b, a ground pattern 93 is provided at a distance from each of the

transmission line patterns

92a and 92b. On the ground pattern 93, a ground conductor portion 95 and a ferrite 99 are sequentially provided. A central line 97 is provided on the upper surface of the ferrite 99, and through

lines

98 a and 98 b are provided on both side surfaces of the ferrite 99. Input /

output conductor portions

94a and 94b connected to the through-

lines

98a and 98b are provided on both side surfaces of the ground conductor portion 95 located below the ferrite 99, respectively. The input /

output conductor portions

94a and 94b are connected to the

transmission line patterns

92a and 92b, respectively. That is, one transmission line pattern 92a is connected to the other transmission line pattern 92b via the input / output conductor portion 94a, the through line 98a, the center line 97, the through line 98b, and the input / output conductor portion 94b.

An insulating portion 96 is provided between the ground conductor portion 95 and the input /

output conductor portions

94a and 94b. The input /

output conductor portions

94a and 94b and the ground conductor portion 95 are arranged close to each other with a predetermined interval i1. Specifically, the predetermined interval i1 is an interval between the input /

output conductor portions

94a and 94b and the ground conductor portion 95 in the signal propagation direction of the

transmission line patterns

92a and 92b.

The material of each line such as the input /

output conductors

94a and 94b, the through

lines

98a and 98b, and the center line 97 is the same as that of the first embodiment, and the line cross-sectional area is 0.01 mm ² . The thicknesses of the ground conductor portion 95 and the ferrite 99 are the same as those in the first embodiment. The relative dielectric constant of the ferrite 99 is ε = 13. The frequency of the high-frequency signal propagating through each line is 28 GHz, and the wavelength is λ = 2.8 mm. The power applied to the transmission line model 90 is 10 dBm.

The simulation result of the power radiation loss using the transmission line model 90 will be described.

FIG. 8A is a graph showing the relationship between the interval i1 between the input /

output conductor portions

94a and 94b and the ground conductor portion 95 and the S parameter. FIG. 8A shows reflection characteristics S11 and transmission characteristics S21 when the horizontal axis is i1 / (λ / 4) and the vertical axis is an S parameter.

FIG. 8B is a graph showing the relationship between the distance i1 between the input /

output conductor portions

94a and 94b and the ground conductor portion 95 and the radiation loss.

FIG. 8B shows the radiation loss when i1 / (λ / 4) is changed. The radiation loss is, for example, the total radiation loss generated in the input / output conductor portion 94a and the lead conductor portion (through-line 98a) out of the electric power input to the input / output conductor portion 94a via the transmission line pattern 92a. Specifically, the radiation loss is a characteristic that does not appear as the reflection characteristic S11 and the transmission characteristic S21 shown in FIG. 8A. The reflection characteristic S11 and the transmission characteristic S21 are magnitude-converted, and the magnitude component is subtracted from 1. Can be sought.

As shown in FIG. 8B, when the distance i1 between the input / output conductor portion 94a and the ground conductor portion 95 is reduced, the radiation loss is reduced. Here, when the allowable level of radiation loss required from the market is set to 30% (0.3), i1 / (λ / 4) = 0.4 from FIG. 8B. Therefore, in order to reduce the radiation loss to 30% or less, the interval i1 is preferably 0 <i1 ≦ 0.1λ. For example, when the wavelength λ is 2.8 mm, the interval i1 is desirably larger than 0 and not larger than 0.28 mm.

From the simulation result of the transmission line, it is desirable that the predetermined interval i1 between the input / output conductor portion 11 and the ground conductor portion 12 of the nonreciprocal circuit element 1 is larger than 0 and not more than 0.1λ. By setting the predetermined interval i1 within the above range, the radiation loss of the transmission signal in the irreversible circuit element 1 can be reduced.

[1.3 Summary]
As described above, the nonreciprocal circuit device 1 shown in the present embodiment is the nonreciprocal circuit device 1 mounted on the surface 50a of the mounting substrate 50, and includes a permanent magnet 30 and a ferrite to which a DC magnetic field is applied by the permanent magnet 30. 40 and a first yoke 10 provided between the ferrite 40 and the mounting substrate 50, and the ferrite 40 is formed on one main surface 40a facing away from the surface located on the first yoke 10 side. A central conductor portion 41, and a lead conductor portion 42 connected to the central conductor portion 41 and drawn out from the central conductor portion 41. The central conductor portion 41 has an LC component, and the first yoke 10 Has an input / output conductor portion 11 connected to the lead conductor portion 42, and a ground conductor portion 12 disposed close to the input / output conductor portion 11 at a predetermined interval i1, Mounting board 5 The input / output conductor portion 11 is connected to the transmission line pattern 51 formed along the surface 50a of the mounting substrate 50, and the input / output conductor portion 11 is connected to the ground pattern 52 formed along the surface 50a. A high frequency signal in the millimeter wave band is input / output via the transmission line pattern 51.

As described above, since the ground conductor portion 12 of the nonreciprocal circuit element 1 that is surface-mounted on the mounting substrate 50 is disposed close to the input / output conductor portion 11, the transmission line pattern 51 passes through the input / output conductor portion 11. The radiation loss of the transmission signal caused by the bent structure of the transmission line in the line reaching the central conductor portion 41 can be reduced.

For example, when the nonreciprocal circuit element 1 is mounted on the mounting substrate 50 and a transmission signal is input from the transmission line pattern 51 on the mounting substrate 50, the bent region HA that bends in a direction perpendicular to the direction in which the transmission line pattern 51 extends. It becomes easy to generate power radiation. However, in the present embodiment, since the ground conductor portion 12 is disposed in the vicinity of the input / output conductor portion 11, radiation loss in the bent region HA can be reduced.

In particular, when transmitting a high-frequency signal such as a millimeter wave band (20 GHz or more), power radiation is likely to be generated in the transmission line. However, in the nonreciprocal circuit device 1 according to the present embodiment, the input is a transmission line. Power radiation in the output conductor portion 11 and the like can be suppressed.

(Embodiment 2)
FIG. 9 is a cross-sectional view showing the nonreciprocal circuit device 1A according to the second exemplary embodiment. In the non-reciprocal circuit device 1 </ b> A, the permanent magnet 30 is located on the side of the ferrite 40.

In the nonreciprocal circuit device 1 </ b> A, the ferrite 40 and the permanent magnet 30 are disposed on the first yoke 10, and the flat plate-like second yoke 20 is disposed on the ferrite 40 and the permanent magnet 30.

The permanent magnet 30 has an annular shape, and the ferrite 40 including the central conductor portion 41 is accommodated inside the inner wall. The permanent magnet 30 is bonded and fixed to the first main surface 10 a of the first yoke 10. By arranging the permanent magnet 30 in this way, a DC magnetic field is applied to the ferrite 40.

The second yoke 20 has a flat plate shape and is bonded and fixed to the upper surface of the permanent magnet 30. The second yoke 20, together with the first yoke 10, applies a magnetic shunt action to the magnetic field formed by the permanent magnet 30.

In FIG. 9, an RF shield that suppresses radiation is not drawn. However, for the purpose of preventing radiation, an RF shield may be disposed inside the permanent magnet 30 or the second yoke 20 so as to cover the central conductor portion 41. good. The RF shield may be an RF shield having no magnetic permeability such as copper.

Also in the present embodiment, since the ground conductor portion 12 of the non-reciprocal circuit element 1A that is surface-mounted on the mounting substrate 50 is disposed close to the input / output conductor portion 11, the input / output conductor portion 11 is connected from the transmission line pattern 51. It is possible to reduce the radiation loss of the transmission signal caused by the bent structure of the transmission line in the line that passes through to the central conductor portion 41.

(Embodiment 3)
The present invention can be realized not only as the above-described non-reciprocal circuit element, but also as a front-end circuit and a communication device including such a non-reciprocal circuit element. Therefore, hereinafter, a communication apparatus including the above-described non-reciprocal circuit element (that is, a communication apparatus incorporating a front-end circuit including the non-reciprocal circuit element) will be described.

FIG. 10 is a functional block diagram of the communication device 3 including the nonreciprocal circuit element 1 described in the first embodiment.

As shown in FIG. 10, the communication device 3 is a base station of a mobile phone, for example, including a front-end circuit 100 having the irreversible circuit element 1, an RFIC (Radio Frequency Integrated Circuit) 200, and an antenna element 300. . Note that the communication device 3 may not include the antenna element 300.

The front end circuit 100 is provided at the front end of the communication device 3 and propagates a transmission signal or a reception signal between the RFIC 200 and the antenna element 300. Specifically, in addition to the nonreciprocal circuit element 1, the front end circuit 100 further includes a transmission side circuit such as a PA (Power Amplifier) 202, a BPF (Band Pass Filter) 203, and an LNA (Low). And a receiving circuit such as Noise Amplifier 204. Further, the front end circuit 100 is provided with a transmission terminal Ptx to which a transmission signal is input, an antenna terminal Pant to which the transmission signal is output and a reception signal is input, and a reception terminal Prx that outputs the reception signal. . The front-end circuit 100 may not include the BPF 203, and may include a matching circuit other than the above, a transmission or reception filter, or the like.

The non-reciprocal circuit device 1 has a first port Port1, a second port Port2, and a third port Port3 corresponding to the input / output terminal 16. The first port Port1 is connected to a transmission side circuit (here, PA202), the second port Port2 is connected to a reception circuit (here, LNA204), and the third port Port3 is connected to an antenna terminal Pant. Specifically, the first port Port 1 is connected to the transmission terminal Ptx via the PA 202, the second port Port 2 is connected to the reception terminal Prx via the LNA 204, and the third port Port 3 is connected to the antenna terminal Pant via the BPF 203. It is connected.

PA 202 is, for example, a power amplification module that amplifies a transmission signal (high-frequency transmission signal) input from the transmission terminal (TX in the figure) of the RFIC 200 to the transmission terminal Ptx of the front end circuit 100.

The BPF 203 allows the transmission signal output from the nonreciprocal circuit element 1 to pass through after filtering in a predetermined use frequency band. Further, the BPF 203 passes the received signal input from the antenna terminal Pant after filtering in the use frequency band.

The LNA 204 is, for example, a low noise amplification module that amplifies the reception signal (high frequency reception signal) output from the nonreciprocal circuit element 1.

Such a front-end circuit 100 amplifies and filters the transmission signal input to the transmission terminal Ptx and outputs it from the antenna terminal Pant, and filters and amplifies the reception signal input to the antenna terminal Pant from the reception terminal Prx. Output. At this time, the transmission signal passes through the Tx path of the nonreciprocal circuit element 1, and the reception signal passes through the Rx path of the nonreciprocal circuit element 1.

The RFIC 200 is a circuit that is connected to the transmission terminal Ptx and the reception terminal Prx of the front end circuit 100 and processes the transmission signal or the reception signal. For example, the RFIC 200 up-converts a transmission signal input from a baseband signal processing circuit (not shown) and outputs it from a transmission terminal (TX in the figure), and inputs from the front end circuit 100 to a reception terminal (RX in the figure). The received signal is down-converted and output to the baseband signal processing circuit.

The antenna element 300 is connected to the antenna terminal Pant of the front end circuit 100, transmits a transmission signal, and receives a reception signal. The shape or the like of the antenna element 300 is not particularly limited, and may be appropriately designed according to the use frequency band of the communication device 3.

According to the communication apparatus 3 described above, the communication quality can be improved by providing the nonreciprocal circuit element 1 in which the radiation loss of the transmission signal is reduced.

(Other variations)
As described above, the nonreciprocal circuit element, the nonreciprocal circuit module, the front end circuit, and the communication device according to the embodiment of the present invention have been described with reference to the embodiment and the modification examples. The reversible circuit module, the front end circuit, and the communication device are not limited to the above embodiment. Another embodiment realized by combining arbitrary constituent elements in the above-described embodiment, and modifications obtained by applying various modifications conceivable by those skilled in the art to the above-described embodiment without departing from the gist of the present invention. Examples and various devices incorporating the nonreciprocal circuit device of the present disclosure are also included in the present invention.

For example, the input / output conductor portion 11 of the non-reciprocal circuit element according to the above embodiment may be directly joined to the transmission line pattern 51 using a conductive adhesive without using the input / output terminal 16. Further, the ground conductor portion 12 may be directly joined to the ground pattern 52 using a conductive adhesive without using the ground terminal 17. The input / output conductor part 11 and the lead conductor part 42 may be connected via a conductive adhesive. The permanent magnet 30 and the ferrite 40 may be joined by a non-conductive adhesive or the like.

For example, the mounting substrate 50 of the nonreciprocal circuit module 2 according to Embodiment 1 is used as an interposer substrate, an external terminal for input / output is provided on the back surface of the mounting substrate 50, and the nonreciprocal circuit module 2 is different from the mounting substrate 50. You may mount in a printed wiring board. When using the irreversible circuit element 1 for the millimeter wave band, it is necessary to design the circuit of the mounting substrate 50 so that a high-frequency signal is not easily radiated, and the circuit design has a great effort. However, the above problem can be solved by preparing the nonreciprocal circuit module 2 on which the nonreciprocal circuit element 1 is appropriately surface-mounted in advance.

For example, in the above description, a three-port non-reciprocal circuit element is described as an example of the non-reciprocal circuit element. The nonreciprocal circuit device may be a two-port isolator having an input port and an output port.

For example, the ground potential may be a circuit ground potential (reference potential) of the nonreciprocal circuit element, and may be 0 V, a ground ground potential (that is, a ground reference potential), or a potential different from the frame ground.

For example, the nonreciprocal circuit device 1 according to the first exemplary embodiment is configured such that the transmission line is bent from the central conductor portion 41 to the transmission line pattern 51 via the lead conductor portion 42, the input / output conductor portion 11, and the input / output terminal 16. Also in the region, the ground conductor portion 12 is provided in the vicinity of the input / output conductor portion 11. Thus, the radiation loss of the transmission signal can also be reduced in the line from the central conductor portion 41 to the transmission line pattern 51.

The present invention can be widely used in communication devices such as mobile phone base stations as non-reciprocal circuit elements arranged in the front end of the communication device.

DESCRIPTION OF

SYMBOLS

1, 1A Nonreciprocal circuit element 2 Nonreciprocal circuit module 3 Communication apparatus 10 1st yoke 10a 1st main surface 10b 2nd main surface 11 I / O conductor part 11a Side surface of I / O conductor part 12 Ground conductor part 13 Insulating part 13a Insulation Side surface 16 Input / output terminal 17 Ground terminal 20 Second yoke 21 Top surface portion 22 Side surface portion 30 Permanent magnet 40 Ferrite 40a One main surface 40b The other main surface (surface located on the first yoke side)
40c side surface 41 central conductor portion 42 lead conductor portion 42a main surface lead portion 42b penetrating lead portion 42c impedance adjustment portion 50 mounting substrate 50a surface of mounting substrate 51 transmission line pattern 52 ground pattern 90 transmission line model 91 mounting

substrate

92a, 92b transmission line Pattern 93

Ground pattern

94a, 94b Input / output conductor part 95 Ground conductor part 96 Insulating part 97

Center line

98a, 98b Through-line 99 Ferrite 100 Front end circuit 200 RFIC
202 PA
203 BPF
204 LNA
300 Antenna element HA Bending region i1 Predetermined interval Pant Antenna terminal Port1 First port Port2 Second port Port3 Third port Prx Reception terminal Ptx Transmission terminal T1 Power transmission path λ Wavelength

Claims

A non-reciprocal circuit device mounted on the surface of the mounting substrate,
With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
A first yoke provided between the ferrite and the mounting substrate;
With
The ferrite includes a central conductor portion formed on one main surface facing away from a surface located on the first yoke side, and a lead conductor portion connected to the central conductor portion and drawn from the central conductor portion. Have
The central conductor portion has an LC component;
The first yoke has an input / output conductor portion connected to the lead conductor portion, and a ground conductor portion disposed close to the input / output conductor portion at a predetermined interval,
The ground conductor portion is connected to a ground pattern formed along the surface of the mounting substrate,
The input / output conductor portion is connected to a transmission line pattern formed along the surface of the mounting substrate,
The input / output conductor portion receives and inputs a high-frequency signal in the millimeter wave band through the transmission line pattern.
Non-reciprocal circuit element.
The central conductor portion is circular.
The nonreciprocal circuit device according to claim 1.
further,
A cylindrical second yoke that covers the permanent magnet and the ferrite;
The second yoke is connected to the ground conductor of the first yoke;
The nonreciprocal circuit device according to claim 1 or 2.
The ferrite and the first yoke are in contact with each other,
The nonreciprocal circuit device according to any one of claims 1 to 3.
Each having three lead conductor portions and three input / output conductor portions;
The nonreciprocal circuit device according to any one of claims 1 to 4.
A nonreciprocal circuit device according to claim 5,
A mounting substrate on which the nonreciprocal circuit element is mounted;
A non-reciprocal circuit module comprising:
The mounting board has a transmission line pattern formed along the surface of the mounting board, and the ground pattern that is disposed close to the transmission line pattern with a space therebetween,
The input / output conductor portions of the non-reciprocal circuit element are respectively connected to the transmission line pattern,
The ground conductor portion of the non-reciprocal circuit element is connected to the ground pattern;
Non-reciprocal circuit module.
When the wavelength of the high-frequency signal input / output to / from the input / output conductor via the transmission line pattern is λ, the predetermined input / output conductor and the ground conductor in the signal propagation direction of the transmission line pattern The interval is greater than 0 and less than or equal to 0.1λ.
The nonreciprocal circuit module according to claim 6.
Of the electric power input to the input / output conductor part via the transmission line pattern, the total radiation loss generated in the input / output conductor part and the lead conductor part is within 30%.
The nonreciprocal circuit module according to claim 6 or 7.
A nonreciprocal circuit device according to claim 5,
A transmitting circuit connected to one of the three input / output conductors;
A receiving side circuit connected to an input / output conductor part different from the input / output conductor part connected to the transmitting side circuit, one of the three input / output conductor parts;
An antenna terminal connected to an input / output conductor portion that is one of the three input / output conductor portions and is different from the input / output conductor portions connected to the transmission side circuit and the reception side circuit;
Front end circuit with.
A signal processing circuit for processing high-frequency signals;
A front end circuit according to claim 9;
A communication device comprising: