WO2014083881A1

WO2014083881A1 - Ferrite absorption type isolator

Info

Publication number: WO2014083881A1
Application number: PCT/JP2013/068953
Authority: WO
Inventors: 長谷川　隆
Original assignee: 株式会社村田製作所
Priority date: 2012-11-27
Filing date: 2013-07-11
Publication date: 2014-06-05

Abstract

The purpose of the present invention is to ensure relatively significant isolation in a ferrite absorption type isolator. A ferrite absorption type isolator equipped with: ferrite (10); a connected conductor (15) which is provided on the ferrite (10) and has a first opening (P1), a second opening (P2), a third opening (P3), and a fourth opening (P4); and permanent magnets (20) which apply a direct-current magnetic field to the ferrite (10).　The connected conductor (15) comprises a main line which is arranged between the first opening (P1) and the second opening (P2) and two sub-lines which are respectively branched from the main line and reach the third opening (P3) and the fourth opening (P4). Two of the four openings are used as input and output ports, reactance components (C1, C2 or L1, L2) are connected to the remaining two openings, and the reactance components are connected to the ground.

Description

Ferrite absorption isolators

The present invention relates to a ferrite absorption isolator, and more particularly to a ferrite absorption isolator used in a microwave band or the like.

Generally, an isolator has a characteristic of transmitting a signal only in a specific direction and not transmitting in a reverse direction, and is mounted on a transmission circuit unit of a mobile communication device such as a mobile phone. And as a ferrite absorption type isolator, the thing of

patent documents

1 and 2 is known, for example. This type of isolator is a magnetic field (circularly polarized wave) that rotates at the intersection when two high-frequency currents with the same amplitude and phase that differ by a quarter wavelength flow through two orthogonal lines (having four openings). ) Occurs, and the phenomenon that the turning direction of circularly polarized waves is reversed according to the electromagnetic wave traveling directions of the two lines is used. That is, a ferrite is placed at the intersection and a static magnetic field is applied by a permanent magnet, and a positive circularly polarized wave or a negatively circularly polarized wave is generated by a reflected wave from the sub line according to the traveling direction of the electromagnetic wave propagating through the main line. . When a positive circular polarization occurs, the signal is absorbed by the magnetic loss of the ferrite, and when a negative circular polarization occurs, the signal passes through without any magnetic loss. A reactance element that reflects a signal is connected to an end of the sub line.

The isolator described in Patent Document 3 is made to reduce the size, and as shown in FIGS. 25 and 26, a joining conductor 115 having three openings P1, P2, and P3 is formed on the ferrite 110, and The junction conductor 115 includes a main line disposed between the first opening P1 and the second opening P2, and a sub line that branches from the main line and reaches the third opening P3. The main line resonates. The reactance element (capacitor C or inductor L) is connected to the third opening P3, and the reactance element is connected to the ground. In the isolator shown in FIG. 26, impedance matching capacitors C111 and C112 are connected to the first opening P1 and the second opening P2, respectively.

By the way, in recent mobile phones, a system that transmits and receives a plurality of frequencies simultaneously in order to transmit and receive voice and data at the same time has appeared, and in order to prevent intermodulation distortion and the like in a transmission amplifier, an isolator is more than ever. Large isolation is required. However, the isolator described in Patent Document 3 has emerged as a problem that the isolation is insufficient for this type of system.

JP-A-63-260201 JP 2001-326504 A International Publication No. 2011/077783

Therefore, an object of the present invention is to provide a ferrite absorption isolator capable of securing a relatively large isolation.

The ferrite absorption isolator according to the first aspect of the present invention is
With ferrite,
A bonding conductor having a first opening, a second opening, a third opening and a fourth opening, disposed in the ferrite;
A permanent magnet for applying a DC magnetic field to the ferrite;
With
The joint conductor is composed of a main line disposed between the first opening and the second opening, and two sub lines branched from the main line to reach the third opening and the fourth opening, respectively.
Two of the four openings are input / output ports, and reactance elements are connected to the remaining two openings, and the reactance elements are connected to the ground,
It is characterized by.

The ferrite absorption isolator according to the second aspect of the present invention is
With ferrite,
A bonding conductor having a first opening, a second opening, a third opening, a fourth opening, and a fifth opening disposed in the ferrite;
A permanent magnet for applying a DC magnetic field to the ferrite;
With
The junction conductor includes a main line disposed between the first opening and the second opening, and three sub lines branched from the main line to reach the third opening, the fourth opening, and the fifth opening, respectively. Consists of
Two of the five openings are input / output ports, and reactance elements are connected to the remaining three openings, and the reactance elements are connected to the ground,
It is characterized by.

In the ferrite absorption type isolators according to the first and second embodiments, when the signal propagates in the forward direction, the reflected wave from the sub line to which the reactance element is connected to the incident wave from the input opening Are adjusted so that their phases are shifted by about 90 degrees and the amplitude is about half. When the signal propagates in the opposite direction, the phase of the reflected wave from the sub line to which the reactance element is connected is opposite to the incident wave from the input opening so that the amplitude is equal. It has been adjusted. As a result, negative elliptically polarized waves are generated in the forward direction, and linearly polarized waves are generated in the reverse direction. Since the negative elliptical polarization has almost zero permeability near the magnetic resonance point, high-frequency energy concentrates outside the ferrite and propagates with low loss. On the other hand, since linearly polarized waves have a large magnetic permeability near the magnetic resonance point, high-frequency energy is concentrated in the ferrite and absorbed by the ferrite due to magnetic resonance loss.

In the isolator, since a plurality of sub-lines are arranged and a reactance element is connected to the opening, isolation is ensured for each sub-line, and the isolation as a whole increases.

According to the present invention, it is possible to obtain a ferrite absorption isolator capable of ensuring a relatively large isolation.

It is a perspective view which shows the ferrite absorption type isolator which is 1st Example. It is a disassembled perspective view which shows the ferrite absorption type isolator which is 1st Example. 1 is an equivalent circuit diagram of a ferrite absorption isolator according to a first embodiment. It is a graph which shows the characteristic of the ferrite absorption type isolator which is the 1st example. It is a graph which shows the characteristic of the ferrite absorption type isolator which is the 2nd example. It is a graph which shows the characteristic of the ferrite absorption type isolator which is 3rd Example. It is a perspective view which shows the ferrite absorption type isolator which is 4th Example. It is a disassembled perspective view which shows the ferrite absorption type isolator which is 4th Example. It is an equivalent circuit schematic of the ferrite absorption type isolator which is the 4th example. It is a graph which shows the characteristic of the ferrite absorption type isolator which is the 4th example. It is a perspective view which shows the ferrite absorption type isolator which is 5th Example. It is a disassembled perspective view which shows the ferrite absorption type isolator which is 5th Example. It is an equivalent circuit diagram of the ferrite absorption type isolator which is the 5th example. It is a graph which shows the characteristic of the ferrite absorption type isolator which is 5th Example. It is a perspective view which shows the ferrite of the ferrite absorption type isolator which is 6th Example. It is a graph which shows the characteristic of the ferrite absorption type isolator which is the 6th example. It is a perspective view which shows the ferrite absorption type isolator which is a 7th Example. It is a disassembled perspective view which shows the ferrite absorption type isolator which is 7th Example. It is the equivalent circuit schematic of the ferrite absorption type isolator which is the 7th example. It is a graph which shows the characteristic of the ferrite absorption type isolator which is the 7th example. It is a perspective view which shows the ferrite absorption type isolator which is 8th Example. It is a disassembled perspective view which shows the ferrite absorption type isolator which is 8th Example. It is an equivalent circuit diagram of a ferrite absorption type isolator which is the eighth embodiment. It is a graph which shows the characteristic of the ferrite absorption type isolator which is the 8th example. It is an equivalent circuit diagram of a ferrite absorption type isolator which is a first conventional example. It is an equivalent circuit diagram of a ferrite absorption type isolator which is a second conventional example.

Hereinafter, embodiments of a ferrite absorption type isolator according to the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to a common component and part, and the overlapping description is abbreviate | omitted. In each figure, the hatched portion indicates a conductor.

(Refer to the first embodiment, FIGS. 1 to 4)
As shown in FIGS. 1 and 2, the ferrite absorption isolator 1 A according to the first embodiment includes a ferrite 10 and a joint conductor 15 having four openings P 1, P 2, P 3, P 4 arranged on the surface of the ferrite 10. And a pair of permanent magnets 20 for applying a DC magnetic field to the ferrite 10, capacitors C1 and C2 as reactance elements, and a mounting substrate 30.

The joining conductor 15 is a thin film formed by vapor deposition using a conductive metal or a thick film formed by applying and baking a conductive paste. The two sub lines branched from the main line arranged between the openings P1 and P2 of the joint conductor 15 extend in the direction substantially orthogonal to the main line and extend upward from the back side of the ferrite 10 to the bottom surface. It wraps around and further wraps around to the surface side. The ends of the two sub-lines are an opening P3 and an opening P4, respectively. One ends of capacitors C1 and C2 are connected to the opening P3 and the fourth opening P4, respectively. In the first embodiment, the main line means a conductor between the openings P1 and P2, and the sub-line means a conductor branched from the substantially central portion of the main line to reach the openings P3 and P4.

The mounting substrate 30 is formed with an input terminal electrode 31, an output terminal electrode 32,

relay terminal electrodes

33 and 34, and

ground terminal electrodes

41 and 42, respectively. The ferrite 10 and the permanent magnet 20 have the same area, and the ferrite 10 is mounted on the mounting substrate 30 with the permanent magnets 20 attached to both side surfaces. At this time, one end (opening P1) of the main line is connected to the input terminal electrode 31, the other end (opening P2) is connected to the output terminal electrode 32, and the end portions (openings P3 and P4) of the sub line are relay terminal electrodes. 33 and 34, respectively. One end of the capacitor C 1 is connected to the relay terminal electrode 33, and the other end is connected to the ground terminal electrode 41. One end of the capacitor C 2 is connected to the relay terminal electrode 34, and the other end is connected to the ground terminal electrode 42.

In the ferrite absorption isolator 1A having the above configuration, when a signal propagates in the forward direction, the reflected wave from the sub-line to which the capacitors C1 and C2 are connected is reflected with respect to the incident wave from the opening P1 or the opening P2. The phase is adjusted to be about 90 degrees and the amplitude is adjusted to about half. When the signal propagates in the opposite direction, the reflected wave from the sub line to which the capacitors C1 and C2 are connected has an opposite phase to the incident wave from the opening P1 or the opening P2, and the amplitude is equal. It has been adjusted to be. As a result, negative elliptically polarized waves are generated in the forward direction, and linearly polarized waves are generated in the reverse direction. Since the negative elliptical polarization has a permeability of almost zero near the magnetic resonance point, high-frequency energy is concentrated outside the ferrite 10 and propagates with low loss. On the other hand, since the linearly polarized wave has a large magnetic permeability near the magnetic resonance point, high-frequency energy is concentrated inside the ferrite 10 and is absorbed by the ferrite 10 due to magnetic resonance loss.

The input return loss of the ferrite absorption isolator 1A according to the first embodiment is shown in FIG. 4A, the isolation is shown in FIG. 4B, the insertion loss is shown in FIG. 4C, and the output return loss is shown. As shown in FIG. The ferrite 10 used had a saturation magnetization of 80 mT, a size having a main surface length of 1.0 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm. Capacitors C1 and C2 have a capacitance of 9 pF. The impedance between the input terminal and the output terminal is 7Ω, and the electrical characteristics are normalized by the input / output 7Ω. In the 824 to 849 MHz band, the insertion loss is 0.75 dB and the isolation is 12.9 dB.

Incidentally, the characteristics of the ferrite absorption isolator 100A shown in FIG. 25 are indicated by thin lines in FIGS. 4 (A) to 4 (D), respectively. In the isolator 100A as the first conventional example, a ferrite 110 having a saturation magnetization of 80 mT, a main surface length of 0.8 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm was used. Capacitor C has a capacitance of 9 pF. The impedance between the input end and the output end is 10Ω, and the electrical characteristics are normalized by the input / output 10Ω. In the 824 to 849 MHz band, the insertion loss is 0.45 dB and the isolation is 6.6 dB. When both are compared, the isolator 1A of the first embodiment is greatly improved in isolation. This is because the isolation is ensured for every two sub-lines, and the isolation as a whole increases.

The ferrite absorption type isolator 1A is incorporated in a transmission circuit module of a mobile communication device, for example. The mounting board 30 may be a printed wiring board for mounting a power amplifier in the transmission circuit module. In this case, the ferrite 10 provided with the joining conductor 15 and having the permanent magnet 20 attached thereto is supplied to the assembling process of the transmission module. This also applies to the embodiments shown below.

(Refer to the second embodiment, FIG. 5)
The ferrite absorption type isolator according to the second embodiment has the same configuration as the isolator 1A according to the first embodiment, and both capacitors C1 and C2 have a capacity of 6 pF.

The input return loss is shown in FIG. 5 (A), the isolation is shown in FIG. 5 (B), the insertion loss is shown in FIG. 5 (C), and the output return loss is shown in FIG. 5 (D). The impedance between the input terminal and the output terminal is 9Ω, and the electrical characteristics are normalized by the input / output 9Ω. In the 824 to 849 MHz band, the insertion loss is 0.56 dB and the isolation is 8.6 dB.

(Refer to the third embodiment, FIG. 6)
The ferrite absorption type isolator according to the third embodiment has the same configuration as the isolator 1A according to the first embodiment, and the capacitor C1 has a capacitance of 9 pF and the capacitor C2 has a capacitance of 6 pF.

The input return loss is shown in FIG. 6 (A), the isolation is shown in FIG. 6 (B), the insertion loss is shown in FIG. 6 (C), and the output return loss is shown in FIG. 6 (D). The impedance between the input end and the output end is 8Ω, and the electrical characteristics are normalized by the input / output 8Ω. In the 824 to 849 MHz band, the insertion loss is 0.66 dB and the isolation is 10.9 dB.

(Refer to the fourth embodiment, FIGS. 7 to 10)
As shown in FIGS. 7 to 9, the ferrite absorption type isolator 1B according to the fourth embodiment is obtained by branching three sub-lines from the main line in the junction conductor 15, and each end of the sub-line is opened. P3, opening P4 and opening P5 are connected to capacitors C1, C2 and C3 as reactance elements, respectively.

As compared with the substrate 30 of the isolator 1A, a relay terminal electrode 35 and a ground terminal electrode 43 are additionally formed on the mounting substrate 30. Here, the end (opening P5) of the third sub-line is connected to the relay terminal electrode 35, and one end of the capacitor C3 is connected to the relay terminal electrode 35, and the other end is connected to the ground terminal electrode 43.

The operation of the ferrite absorption isolator 1B according to the fourth embodiment is the same as that of the isolator 1A. The input return loss is shown in FIG. 10A, the isolation is shown in FIG. 10B, and the insertion loss is shown. 10 (C), and the output return loss is shown in FIG. 10 (D). The ferrite 10 used had a saturation magnetization of 80 mT, a size having a main surface length of 1.3 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm. Capacitors C1, C2, and C3 have a capacitance of 9 pF. The impedance between the input terminal and the output terminal is 7Ω, and the electrical characteristics are normalized by the input / output 7Ω. In the 824 to 849 MHz band, the insertion loss is 0.98 dB and the isolation is 14.4 dB.

As can be seen by comparing the isolation shown in FIG. 10 (B) with the isolation shown in FIG. 4 (B), the number of sub-lines increases in this fourth embodiment, so that the isolation as a whole is further improved. improves.

(Fifth embodiment, see FIGS. 11 to 14)
In the ferrite absorption type isolator 1C according to the fifth embodiment, the configuration of the bonding conductor 15 is the same as that of the isolator 1A according to the first embodiment, and inductors L1 and L2 are used as reactance elements. Further, capacitors C11 and C12 dropped to the ground are connected to the openings P1 and P2 which are the input end and the output end, respectively. Capacitors C11 and C12 are for matching input / output impedances.

relay terminal electrodes

33, 34, and

ground terminal electrodes

41, 42, 43, respectively. One end (opening P1) of the main line is connected to the input terminal electrode 31, the other end (opening P2) is connected to the output terminal electrode 32, and the end parts (openings P3 and P4) of the sub line are connected to the

relay terminal electrodes

33 and 34. Connected to each. One end of the inductor L1 is connected to the relay terminal electrode 33 and the other end is connected to the ground terminal electrode 41. One end of the inductor L2 is connected to the relay terminal electrode 34, and the other end is connected to the ground terminal electrode 42. One end of the capacitor C 11 is connected to the input terminal electrode 31, and the other end is connected to the ground terminal electrode 43. The capacitor C12 has one end connected to the output terminal electrode 32 and the other end connected to the ground terminal electrode 43.

The operation of the ferrite absorption type isolator 1C according to the fifth embodiment is basically the same as that of the isolator 1A. The input return loss is shown in FIG. 14A, the isolation is shown in FIG. The loss is shown in FIG. 14C, and the output return loss is shown in FIG. The ferrite 10 used had a saturation magnetization of 80 mT, a size having a main surface length of 1.0 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm. The inductances of the inductors L1 and L2 are both 2nH. Capacitors C11 and C12 have a capacitance of 14 pF. The impedance between the input terminal and the output terminal is 7Ω, and the electrical characteristics are normalized by the input / output 7Ω. In the 824 to 849 MHz band, the insertion loss is 2.53 dB and the isolation is 18.0 dB. As described above, even when the reactance element connected to the sub line is an inductor, the isolation can be improved by increasing the number of branches.

Incidentally, the characteristics of the ferrite absorption isolator 100B shown in FIG. 26 are indicated by thin lines in FIGS. 14 (A) to (D), respectively. In the isolator 100B as the second conventional example, the ferrite 110 having a saturation magnetization of 80 mT, a size having a main surface length of 0.8 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm was used. The inductance of the inductor L is 2 nH. The capacitances of the capacitors C111 and C112 are both 8 pF. The impedance between the input end and the output end is 10Ω, and the electrical characteristics are normalized by the input / output 10Ω. In the 824 to 849 MHz band, the insertion loss is 1.33 dB and the isolation is 9.2 dB. When both are compared, the isolator 1C according to the fifth embodiment is greatly improved in isolation.

(See the sixth embodiment, FIGS. 15 and 16)
As shown in FIG. 15, in the ferrite absorption type isolator according to the sixth embodiment, the sub-line is branched into two lines from one place in the substantially central portion of the main line. Other configurations are the same as those of the isolator 1A according to the first embodiment.

The operation of the ferrite absorption type isolator according to the sixth embodiment is basically the same as that of the isolator 1A. The input return loss is shown in FIG. 16A, the isolation is shown in FIG. Is shown in FIG. 16C, and the output return loss is shown in FIG. The ferrite 10 used had a saturation magnetization of 80 mT, a size having a main surface length of 1.0 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm. Capacitors C1 and C2 have a capacitance of 9 pF. The impedance between the input terminal and the output terminal is 7Ω, and the electrical characteristics are normalized by the input / output 7Ω. In the 824 to 849 MHz band, the insertion loss is 0.78 dB and the isolation is 13.0 dB.

(Refer to the seventh embodiment, FIGS. 17 to 20)
As shown in FIGS. 17 to 19, the ferrite absorption type isolator 1D according to the seventh embodiment has an opening P1 as an input port and an opening P3 as an output port. Capacitors C1 and C2 are connected. In the seventh embodiment, the line extending from the opening P1 to the opening P3 is the main line, and the two lines branched from the main line and reaching the opening P2 and the opening P4, respectively, are the sub lines.

relay terminal electrodes

33 and 34, and

ground terminal electrodes

41 and 42, respectively. One end (opening P1) of the main line is connected to the input terminal electrode 31, the other end (opening P3) is connected to the output terminal electrode 32, and the end parts (openings P2, P4) of the sub line are connected to the

relay terminal electrodes

33, 34. Connected to each. One end of the capacitor C 1 is connected to the relay terminal electrode 34, and the other end is connected to the ground terminal electrode 42. One end of the capacitor C 2 is connected to the relay terminal electrode 33, and the other end is connected to the ground terminal electrode 41.

The operation of the ferrite absorption isolator 1D having the above configuration is basically the same as that of the isolator 1A. The input return loss is shown in FIG. 20A, the isolation is shown in FIG. Is shown in FIG. 20C, and the output return loss is shown in FIG. The ferrite 10 used had a saturation magnetization of 80 mT, a size having a main surface length of 1.0 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm. Capacitors C1 and C2 have a capacitance of 9 pF. The impedance between the input end and the output end is 10Ω, and the electrical characteristics are normalized by the input / output 10Ω. In the 824 to 849 MHz band, the insertion loss is 1.75 dB and the isolation is 13.2 dB.

(Eighth embodiment, see FIGS. 21 to 24)
As shown in FIGS. 21 to 23, the ferrite absorption isolator 1E according to the eighth embodiment has an opening P3 as an input port and an opening P4 as an output port. The opening P1 and the opening P2 each have a reactance element. Capacitors C1 and C2 are connected. In the eighth embodiment, the line extending from the opening P3 to the opening P4 is the main line, and the two lines branching from the main line and respectively reaching the opening P1 and the opening P2 are sub-lines.

relay terminal electrodes

33 and 34, and a ground terminal electrode 44, respectively. One end (opening P3) of the main line is connected to the input terminal electrode 31, the other end (opening P4) is connected to the output terminal electrode 32, and the end portions (openings P1, P2) of the sub line are connected to the

relay terminal electrodes

33, 34. Connected to each. One end of the capacitor C 1 is connected to the relay terminal electrode 33, and the other end is connected to the ground terminal electrode 44. One end of the capacitor C 2 is connected to the relay terminal electrode 34, and the other end is connected to the ground terminal electrode 44.

The operation of the ferrite absorption isolator 1E having the above configuration is basically the same as that of the isolator 1A. The input return loss is shown in FIG. 24A, the isolation is shown in FIG. Is shown in FIG. 24C, and the output return loss is shown in FIG. The ferrite 10 used had a saturation magnetization of 80 mT, a size having a main surface length of 1.0 mm, a main surface height of 0.5 mm, and a thickness of 0.15 mm. Capacitors C1 and C2 have a capacitance of 9 pF. The impedance between the input end and the output end is 8Ω, and the electrical characteristics are normalized by the input / output 8Ω. In the 824 to 849 MHz band, the insertion loss is 1.74 dB and the isolation is 9.5 dB.

In addition, the ferrite absorption type isolator according to the present invention is not limited to the above embodiment, and can be variously modified within the scope of the gist thereof.

For example, the routing shape of the joining conductor is arbitrary, and the size of the ferrite, the numerical value of the saturation magnetization, and the numerical value of the reactance element shown in each example are not limited thereto. Further, the size, shape, structure, etc. of the mounting substrate are arbitrary.

As described above, the present invention is useful for ferrite absorption isolators, and is particularly excellent in that a relatively large isolation can be secured.

DESCRIPTION OF SYMBOLS 1A-1E ... Ferrite absorption type isolator 10 ... Ferrite 15 ... Joining conductor 20 ... Permanent magnet 30 ... Mounting board P1, P2, P3, P4, P5 ... Opening C1, C2 ... Capacitor L1, L2 ... Inductor

Claims

With ferrite,
A bonding conductor having a first opening, a second opening, a third opening and a fourth opening, disposed in the ferrite;
A permanent magnet for applying a DC magnetic field to the ferrite;
With
The joint conductor is composed of a main line disposed between the first opening and the second opening, and two sub lines branched from the main line to reach the third opening and the fourth opening, respectively.
Two of the four openings are input / output ports, and reactance elements are connected to the remaining two openings, and the reactance elements are connected to the ground,
Ferrite absorption isolator characterized by
The ferrite absorption isolator according to claim 1, wherein the first opening and the second opening are input / output ports.
With ferrite,
A bonding conductor having a first opening, a second opening, a third opening, a fourth opening, and a fifth opening disposed in the ferrite;
A permanent magnet for applying a DC magnetic field to the ferrite;
With
The junction conductor includes a main line disposed between the first opening and the second opening, and three sub lines branched from the main line to reach the third opening, the fourth opening, and the fifth opening, respectively. Consists of
Two of the five openings are input / output ports, and reactance elements are connected to the remaining three openings, and the reactance elements are connected to the ground,
Ferrite absorption isolator characterized by
The ferrite absorption isolator according to any one of claims 1 to 3, wherein the reactance element is a capacitor.
The ferrite absorption isolator according to any one of claims 1 to 3, wherein the reactance element is an inductor.