JP5045564B2 - Non-reciprocal circuit element - Google Patents

Description

  The present invention relates to a nonreciprocal circuit device, and more particularly to a nonreciprocal circuit device such as an isolator or a circulator used in a microwave band.

  Conventionally, nonreciprocal circuit elements such as isolators and circulators have a characteristic of transmitting a signal only in a predetermined specific direction and not transmitting in a reverse direction. Utilizing this characteristic, for example, an isolator is used in a transmission circuit unit of a mobile communication device such as a car phone or a mobile phone.

  As a non-reciprocal circuit device of this type, as a two-port isolator, as shown in FIG. 6 of Patent Document 1, the first center electrode and the second center electrode are arranged on the surface of ferrite so as to cross each other in an insulated state. A resistor is connected between one end of the first center electrode connected to the input port and one end of the second center electrode connected to the output port, and an inductor is connected in series with the resistor. It has been.

  This two-port isolator achieves an insertion loss bandwidth and an isolation bandwidth that can withstand practical use by setting the crossing angle of the first and second center electrodes to 40 ° to 80 °. The inductor is provided to compensate for a phase shift caused by shifting the crossing angle from 90 °. However, when the insertion loss bandwidth is widened, the isolation bandwidth is narrowed. Conversely, when the isolation bandwidth is widened, the insertion loss bandwidth is narrowed.

  Also, as shown in FIGS. 6 and 7 of Patent Document 2, the first center electrode and the second center electrode are arranged so as to intersect with each other in an insulated state, and one end of the first center electrode is connected to the input port. The other end of the first center electrode and one end of the second center electrode are connected to the output port, the other end of the second center electrode is connected to the ground port, and the matching is performed between the input port and the output port. A capacitor and a resistor connected in parallel are known.

Although this two-port isolator has the advantage of greatly reducing the insertion loss, it is desired to increase the isolation bandwidth.
JP 2003-046307 A International Publication No. 2007/046229 Pamphlet

  Therefore, an object of the present invention is to provide a non-reciprocal circuit device capable of improving the isolation characteristics without increasing the insertion loss.

In order to achieve the above object, the non-reciprocal circuit device according to the first aspect of the present invention comprises:
With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
First and second center electrodes disposed in an insulated state intersecting with the ferrite;
A circuit board holding the permanent magnet and the ferrite;
With
The first center electrode has one end electrically connected to the input port and the other end electrically connected to the output port;
The second center electrode has one end electrically connected to the output port and the other end electrically connected to the ground port.
A first matching capacitor is electrically connected between the input port and the output port;
A second matching capacitor is electrically connected between the output port and the ground port;
A resistor is electrically connected between the input port and the output port,
An LC resonant circuit is electrically connected in series with the resistor between the input port and the output port, and the LC resonant circuit includes a capacitor and an inductor connected in series with each other, and the capacitor is connected to the input port. Arranged on the port side and the inductor is arranged on the output port side,
Each of the capacitor and the inductor is a chip-like element, and is mounted on the surface of the circuit board and electrically connected to each other via a strip line provided on the circuit board.
It is characterized by.

The non-reciprocal circuit device according to the second aspect of the present invention is
The LC resonant circuit comprises one capacitor and two inductors electrically connected to both sides of the capacitor,
Each of the capacitor and the inductor is a chip-like element, and is mounted on the surface of the circuit board and electrically connected to each other via a strip line provided on the circuit board.
It is characterized by.

The non-reciprocal circuit device according to the third aspect of the present invention is
The LC resonant circuit comprises one inductor and two capacitors electrically connected to both sides of the inductor,
Each of the inductor and the capacitor is a chip-like element, mounted on the surface of the circuit board and electrically connected to each other via a strip line provided on the circuit board;
It is characterized by.

  In the nonreciprocal circuit device, an LC resonance circuit comprising an inductor and a capacitor made of chip-like elements connected in series with each other in a stripline is connected between the input port and the output port in series. Therefore, when a high frequency current is input to the output port, the impedance characteristics of the resistor and the LC resonance circuit are matched in a wide band, and the isolation characteristics are improved. On the other hand, during an operation in which a high frequency current flows from the input port to the output port, a large high frequency current flows through the second center electrode, and almost no high frequency current flows through the first center electrode and the resistor. Therefore, even if the LC resonance circuit is added, the loss due to it can be ignored, and the insertion loss does not increase.

  According to the present invention, since the LC resonance circuit in which the inductor and the capacitor made of the chip-like element are electrically connected via the strip line is provided between the input port and the output port in series with the resistor, the insertion loss Isolation characteristics can be improved while maintaining the characteristics.

  Embodiments of a nonreciprocal circuit device according to the present invention will be described below with reference to the accompanying drawings.

(See Example 1, FIGS. 1 to 7)
FIG. 1 shows an equivalent circuit of a 2-port isolator that is Embodiment 1. In FIG. This two-port type isolator is a lumped constant type isolator, and is arranged on the ferrite 32 such that the first center electrode 35 constituting the inductor L1 and the second center electrode 36 constituting the inductor L2 cross each other in an insulated state. Is.

  One end of the first center electrode 35 is connected to the input port P1, and is connected to the input terminal electrode 26 via the matching capacitor CS1. The other end of the first center electrode 35 and one end of the second center electrode 36 are connected to the output port P2 and connected to the output terminal electrode 27 through the matching capacitor CS2, and the other end of the second center electrode 36 is connected. Is connected to the ground port P3.

  A matching capacitor C1 is connected in parallel with the first center electrode 35 between the input port P1 and the output port P2, and for matching in parallel with the second center electrode 36 between the output port P2 and the ground port P3. A capacitor C2 is connected. Between the input port P1 and the output port P2, a resistor R and an LC series resonance circuit (consisting of an inductor L3 and a capacitor C3) are connected in parallel with the first center electrode 35.

  In the two-port isolator having the above circuit configuration, when a high frequency current is input to the input terminal electrode 26, a large high frequency current flows through the second center electrode 36, and almost all high frequency current flows through the first center electrode 35. In addition, the insertion loss is small and it operates in a wide band. During this operation, almost no high-frequency current flows through the resistor R or the LC series resonance circuit (inductor L3 and capacitor C3). Therefore, the loss due to the LC series resonance circuit can be ignored and the insertion loss does not increase.

  On the other hand, when a high-frequency current is input to the output terminal electrode 27, the impedance characteristics of the resistor R and the LC series resonance circuit are matched in a wide band, and the isolation characteristics are improved. Such isolation, insertion loss, and input / output return loss characteristics will be described later with reference to FIG.

  Next, a specific configuration of the two-port isolator shown in FIG. 1 will be described with reference to FIGS. This lumped constant type two-port isolator is roughly composed of a circuit board 20, a ferrite / magnet element 30 composed of a ferrite 32 and a permanent magnet 41, and matching circuit elements C1, C2, CS1, CS2 composed of chip-shaped elements. , R, and resonant circuit elements C3 and L3 composed of chip-like elements.

  As shown in FIG. 3, the ferrite 32 is formed with a first center electrode 35 and a second center electrode 36 that are electrically insulated from each other on the front and back main surfaces 32a and 32b. Here, the ferrite 32 has a rectangular parallelepiped shape having a first main surface 32a and a second main surface 32b which are parallel to each other.

  The permanent magnet 41 faces the main surfaces 32a and 32b so as to apply a DC magnetic field to the ferrite 32 in a direction substantially perpendicular to the main surfaces 32a and 32b, for example, an epoxy-based adhesive 42 (see FIG. 5). ) To form a ferrite / magnet element 30. The main surface 41a of the permanent magnet 41 has the same dimensions as the main surfaces 32a and 32b of the ferrite 32, and is arranged with the main surfaces 32a and 41a and the main surfaces 32b and 41a facing each other so that their external shapes coincide with each other. Yes.

  The first center electrode 35 is formed of a conductor film. That is, as shown in FIG. 3, the first main surface 32a of the ferrite 32 rises from the lower right and branches into two, and is formed at an upper left and inclined at a relatively small angle with respect to the long side. Is formed in a state where it branches into the second main surface 32b via the relay electrode 35a on the upper surface 32c and is branched into two so as to overlap the first main surface 32a in a transparent state on the second main surface 32b, One end thereof is connected to a connection electrode 35b formed on the lower surface 32d. The other end of the first center electrode 35 is connected to a connection electrode 35c formed on the lower surface 32d. Thus, the first center electrode 35 is wound around the ferrite 32 for one turn. And the 1st center electrode 35 and the 2nd center electrode 36 demonstrated below cross | intersect in the state insulated by mutually forming the insulating film.

  The second center electrode 36 is formed of a conductor film. First, the 0.5th turn 36a is formed on the first main surface 32a so as to be inclined from the lower right to the upper left with a relatively large angle with respect to the long side and intersecting the first center electrode 35, and on the upper surface 32c. The first turn 36c is formed so as to cross the first central electrode 35 substantially perpendicularly on the second main surface 32b by going around the second main surface 32b via the relay electrode 36b. The lower end of the first turn 36c wraps around the first main surface 32a via the relay electrode 36d on the lower surface 32d, and the 1.5th turn 36e is first in parallel with the 0.5th turn 36a on the first main surface 32a. It is formed in a state of intersecting with the center electrode 35 and wraps around the second main surface 32b via the relay electrode 36f on the upper surface 32c. Similarly, the second turn 36g, the relay electrode 36h, the 2.5th turn 36i, the relay electrode 36j, the third turn 36k, the relay electrode 36l, the 3.5th turn 36m, the relay electrode 36n, the fourth turn The eyes 36o are formed on the surface of the ferrite 32, respectively. Further, both ends of the second center electrode 36 are connected to connection electrodes 35c and 36p formed on the lower surface 32d of the ferrite 32, respectively. The connection electrode 35 c is shared as a connection electrode at each end of the first center electrode 35 and the second center electrode 36.

  Further, the connection electrodes 35b, 35c, 36p and the relay electrodes 35a, 36b, 36d, 36f, 36h, 36j, 36l, 36n are formed in the recesses 37 (see FIG. 4) formed in the upper and lower surfaces 32c, 32d of the ferrite 32. It is formed by filling a conductive material for an electrode such as silver, a silver alloy, copper, or a copper alloy. In addition, dummy recesses 38 are formed on the upper and lower surfaces 32c and 32d in parallel with various electrodes, and dummy electrodes 39a, 39b, and 39c are formed. This type of electrode is formed by forming a through hole in the mother ferrite substrate in advance, filling the through hole with an electrode conductive material, and then cutting the through hole at a position where the through hole is divided. Various electrodes may be formed as conductor films in the recesses 37 and 38.

  As the ferrite 32, YIG ferrite or the like is used. The first and second center electrodes 35 and 36 and various electrodes can be formed as a thick film or thin film of silver or a silver alloy by a method such as printing, transfer, or photolithography. As the insulating film of the center electrodes 35 and 36, a dielectric thick film such as glass or alumina, a resin film such as polyimide, or the like can be used. These can also be formed by methods such as printing, transfer, and photolithography.

  The ferrite 32 can be integrally fired with a magnetic material including an insulating film and various electrodes. In this case, Cu, Pd, Ag, or Pd / Ag that can withstand high-temperature firing of various electrodes is used.

  As the permanent magnet 41, a strontium-based, barium-based, or lanthanum-cobalt-based ferrite magnet is usually used. As the adhesive 42 for adhering the permanent magnet 41 and the ferrite 32, it is optimal to use a one-component thermosetting epoxy adhesive.

  The circuit board 20 is made of the same kind of material as that of a normal printed wiring circuit board, and on the surface thereof, the matching circuit elements C1, C2, CS1, CS2, R and the chip made of the ferrite / magnet element 30 or chip-like elements are formed. Terminal electrodes 25a, 25b, 25c, and 25d, input terminal electrodes 26, output terminal electrodes 27, and ground terminal electrodes 28a and 28b for mounting the resonant circuit elements C3 and L3, each of which is an element, are formed.

  The ferrite magnet element 30 is placed on the circuit board 20, and the electrodes 35b, 35c, 36p on the lower surface 32d of the ferrite 32 are mounted on the terminal electrodes 25a, 25b, 25c by reflow soldering or the like. Further, the matching circuit elements C1, C2, CS1, CS2, R and the resonant circuit elements C3, L3 are also formed of the electrodes 25a to 25d, 26, 27, 28a, 28b so as to constitute respective circuits (see FIG. 1). It is mounted by reflow soldering.

  The capacitor C3 constituting the LC series resonance circuit is disposed on the input port P1 side, and the inductor L3 is disposed on the output port P2 side. The capacitor C3 is mounted on the terminal electrodes 25a and 25c on the circuit board 20, and the inductor L3 is mounted on the terminal electrodes 25c and 25d, and they are electrically connected to each other via the terminal electrode 25c (strip line SL1). ing.

  Here, the characteristics of the isolation, insertion loss, input return loss, and output return loss of the 2-port isolator according to the first embodiment will be described with reference to FIG. For comparison, the characteristics of Comparative Example 1 having the equivalent circuit shown in FIG. 6 are also shown in FIG. In Comparative Example 1, the LC series resonance circuit is configured by the capacitor C3 and the inductor L3, but the inductor L3 is disposed on the input port P1 side and the capacitor C3 is disposed on the output port P2 side. The rest of the configuration is the same as that of the first embodiment. The conditions of Example 1 and Comparative Example 1 are as follows.

Example 1:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.6 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.1pF
Capacitor CS2: 1.3pF
Resistance R: 105Ω
Capacitor C3: 0.1 pF
Inductor L3: 51 nH
Strip line SL1: thickness 0.2 mm, dielectric constant 4.5, line width 0.3 mm, line length 0.3 mm

Comparative Example 1:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.5 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.5pF
Capacitor CS2: 1.1 pF
Resistance R: 177Ω
Capacitor C3: 0.1 pF
Inductor L3: 50 nH
Strip line SL1: thickness 0.2 mm, dielectric constant 4.5, line width 0.3 mm, line length 0.3 mm

  7A shows the input return loss characteristic, FIG. 7B shows the isolation characteristic, FIG. 7C shows the insertion loss characteristic, and FIG. 7D shows the output return loss characteristic. These characteristics are simulated in the band of 1750 to 2150 MHz. As is clear from the comparison between Example 1 and Comparative Example 1, in Example 1, the isolation is improved and the output return loss is also improved without causing deterioration of the insertion loss.

(See Example 2, FIGS. 8 to 12)
FIG. 8 shows an equivalent circuit of a 2-port isolator that is Embodiment 2. In FIG. The circuit configuration is basically the same as that of the first embodiment, and the configurations of the ferrite / magnet element 30 and the circuit board 20 are basically the same as those of the first embodiment.

  The difference is that the LC series resonance circuit is composed of one capacitor C3 and two inductors L3 and L4 electrically connected to both sides of the capacitor C3. As shown in FIG. 9, the capacitor C3 and the inductors L3 and L4 are each formed of a chip-like element. The capacitor C3 is mounted on the terminal electrodes 25c and 25d on the circuit board 20, the inductor L3 is mounted on the terminal electrodes 25d and 25e, and the inductor L4 is mounted on the terminal electrodes 25a and 25c. Capacitor C3 and inductor L3 are electrically connected through terminal electrode 25d (strip line SL1), and capacitor C3 and inductor L4 are electrically connected through terminal electrode 25c (strip line SL2).

  Here, the characteristics of the isolation, insertion loss, input return loss, and output return loss of the 2-port isolator according to the second embodiment will be described with reference to FIG. For comparison, the characteristics of Comparative Examples 2A and 2B having the equivalent circuits shown in FIGS. 10 and 11 are also shown in FIG. In Comparative Example 2A, an LC series resonance circuit is configured by connecting an inductor L3, an inductor L4, and a capacitor C3 in series from the input port P1 side, and strip lines SL1 and SL2 are interposed therebetween. In the comparative example 2B, an LC series resonance circuit is configured by connecting a capacitor C3, an inductor L3, and an inductor L4 in series from the input port P1 side, and strip lines SL1 and SL2 are interposed therebetween. Other than that, the configuration is the same as that of the second embodiment. The conditions of Example 2 and Comparative Examples 2A and 2B are as follows.

Example 2:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.6 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.1pF
Capacitor CS2: 1.2pF
Resistance R: 143Ω
Capacitor C3: 0.1 pF
Inductor L3: 29 nH
Inductor L4: 29 nH
Strip line SL1, SL2: thickness 0.2mm, dielectric constant 4.5, line width 0.3mm, line length 0.3mm

Comparative Example 2A:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.5 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.5pF
Capacitor CS2: 1.0 pF
Resistance R: 207Ω
Capacitor C3: 0.1 pF
Inductor L3: 24 nH
Inductor L4: 24 nH
Strip line SL1, SL2: thickness 0.2mm, dielectric constant 4.5, line width 0.3mm, line length 0.3mm

Comparative Example 2B:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.6 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.0 pF
Capacitor CS2: 1.4pF
Resistance R: 97Ω
Capacitor C3: 0.1 pF
Inductor L3: 24 nH
Inductor L4: 24 nH
Strip line SL1, SL2: thickness 0.2mm, dielectric constant 4.5, line width 0.3mm, line length 0.3mm

  In FIG. 12, (A) shows the input return loss characteristic, (B) shows the isolation characteristic, (C) shows the insertion loss characteristic, and (D) shows the output return loss characteristic. These characteristics are simulated in the band of 1750 to 2150 MHz. As is clear from the comparison between Example 2 and Comparative Examples 2A and 2B, in Example 2, the isolation is improved and the input / output return loss is also improved without causing deterioration of the insertion loss.

(See Example 3, FIGS. 13 to 17)
FIG. 13 shows an equivalent circuit of the 2-port isolator which is Embodiment 3. The circuit configuration is basically the same as that of the first embodiment, and the configurations of the ferrite / magnet element 30 and the circuit board 20 are basically the same as those of the first embodiment.

  The difference is that the LC series resonance circuit is composed of one inductor L3 and two capacitors C3 and C4 electrically connected to both sides of the inductor L3. As shown in FIG. 14, the inductor L3 and the capacitors C3 and C4 are each composed of a chip-like element. The inductor L3 is mounted on the terminal electrodes 25c and 25d on the circuit board 20, the capacitor C3 is mounted on the terminal electrodes 25d and 25e, and the capacitor C4 is mounted on the terminal electrodes 25a and 25c. The inductor L3 and the capacitor C3 are electrically connected via a terminal electrode 25d (strip line SL1), and the inductor L3 and the capacitor C4 are electrically connected via a terminal electrode 25c (strip line SL2).

  Here, characteristics of the isolation, insertion loss, input return loss, and output return loss of the 2-port isolator according to the third embodiment will be described with reference to FIG. For comparison, the characteristics of Comparative Examples 3A and 3B having the equivalent circuits shown in FIGS. 15 and 16 are also shown in FIG. In Comparative Example 3A, an LC series resonance circuit is configured by connecting a capacitor C3, a capacitor C4, and an inductor L3 in series from the input port P1 side, and strip lines SL1 and SL2 are interposed therebetween. In Comparative Example 3B, an LC series resonance circuit is configured by connecting an inductor L3, a capacitor C3, and a capacitor C4 in series from the input port P1 side, and strip lines SL1 and SL2 are interposed therebetween. The rest of the configuration is the same as that of the first embodiment. The conditions of Example 3 and Comparative Examples 3A and 3B are as follows.

Example 3:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.5 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.1pF
Capacitor CS2: 1.2pF
Resistance R: 137Ω
Capacitor C3: 0.2 pF
Capacitor C4: 0.2pF
Inductor L3: 57 nH
Strip line SL1, SL2: thickness 0.2mm, dielectric constant 4.5, line width 0.3mm, line length 0.3mm

Comparative Example 3A:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.6 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.0 pF
Capacitor CS2: 1.5pF
Resistance R: 92Ω
Capacitor C3: 0.2 pF
Capacitor C4: 0.2pF
Inductor L3: 48 nH
Strip line SL1, SL2: thickness 0.2mm, dielectric constant 4.5, line width 0.3mm, line length 0.3mm

Comparative Example 3B:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.5 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.5pF
Capacitor CS2: 1.0 pF
Resistance R: 210Ω
Capacitor C3: 0.2 pF
Capacitor C4: 0.2pF
Inductor L3: 48 nH
Strip line SL1, SL2: thickness 0.2mm, dielectric constant 4.5, line width 0.3mm, line length 0.3mm

  In FIG. 17, (A) shows the input return loss characteristic, (B) shows the isolation characteristic, (C) shows the insertion loss characteristic, and (D) shows the output return loss characteristic. These characteristics are simulated in the band of 1750 to 2150 MHz. As is clear from a comparison between Example 3 and Comparative Examples 3A and 3B, Example 3 improves isolation and improves input / output return loss without causing deterioration of insertion loss.

(Summary of characteristics)
Table 1 below shows the input return loss, insertion loss, isolation, and output return loss 1850 of Example 1, Comparative Example 1, Example 2, Comparative Examples 2A and 2B, Example 3, and Comparative Examples 3A and 3B. The worst values in the ~ 2050 MHz band are shown together. The conventional example shown in the uppermost stage is a two-port isolator in which the LC series resonance circuit (capacitor C3 inductor L3 and stripline SL1) is omitted in the first embodiment, and the conditions are as follows. Table 1 also shows that Examples 1, 2, and 3 show preferable values for both insertion loss and isolation.

Conventional example:
First center electrode L1: 2.0 nH
Second center electrode L2: 3.8 nH
Capacitor C1: 2.6 pF
Capacitor C2: 0.3 pF
Capacitor CS1: 1.2pF
Capacitor CS2: 1.2pF
Resistance R: 170Ω

(Other examples)
The non-reciprocal circuit device according to the present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the gist thereof.

  For example, if the N pole and S pole of the permanent magnet 41 are reversed, the input port P1 and the output port P2 are switched. Further, the shapes of the first and second center electrodes 35 and 36 can be variously changed. For example, in the first embodiment, the first center electrode 35 has been split into two on the main surfaces 32a and 32b of the ferrite 32. However, the first center electrode 35 may not be branched. Moreover, the 2nd center electrode 36 should just be wound 1 turn or more.

1 is an equivalent circuit diagram illustrating Example 1. FIG. 1 is an exploded perspective view showing Example 1. FIG. It is a perspective view which shows the ferrite with a center electrode. It is a perspective view which shows the said ferrite. It is a disassembled perspective view which shows a ferrite magnet element. 6 is an equivalent circuit diagram illustrating a comparative example 1. FIG. It is a graph which shows the characteristic of Example 1 and Comparative Example 1, (A) shows an input return loss characteristic, (B) shows an isolation characteristic, (C) shows an insertion loss characteristic, (D) shows an output. Shows return loss characteristics. FIG. 6 is an equivalent circuit diagram showing a second embodiment. FIG. 6 is an exploded perspective view showing a second embodiment. It is an equivalent circuit diagram which shows the comparative example 2A. It is an equivalent circuit diagram which shows the comparative example 2B. It is a graph which shows the characteristic of Example 2 and Comparative Examples 2A and 2B, (A) shows an input return loss characteristic, (B) shows an isolation characteristic, (C) shows an insertion loss characteristic, (D) Indicates output return loss characteristics. 6 is an equivalent circuit diagram illustrating Example 3. FIG. 10 is an exploded perspective view showing Example 3. FIG. FIG. 6 is an equivalent circuit diagram showing a comparative example 3A. It is an equivalent circuit diagram which shows the comparative example 3B. It is a graph which shows the characteristic of Example 3 and comparative example 3A, 3B, (A) shows an input return loss characteristic, (B) shows an isolation characteristic, (C) shows an insertion loss characteristic, (D) Indicates output return loss characteristics.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Circuit board 30 ... Ferrite magnet element 32 ... Ferrite 35 ... 1st center electrode 36 ... 2nd center electrode 41 ... Permanent magnet P1 ... Input port P2 ... Output port P3 ... Ground port C1-C4 ... Capacitor L1-L4 ... Inductor R ... Resistance SL1, SL2 ... Stripline

Claims (3)

With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
First and second center electrodes disposed in an insulated state intersecting with the ferrite;
A circuit board holding the permanent magnet and the ferrite;
With
The first center electrode has one end electrically connected to the input port and the other end electrically connected to the output port;
The second center electrode has one end electrically connected to the output port and the other end electrically connected to the ground port.
A first matching capacitor is electrically connected between the input port and the output port;
A second matching capacitor is electrically connected between the output port and the ground port;
A resistor is electrically connected between the input port and the output port,
An LC resonant circuit is electrically connected in series with the resistor between the input port and the output port, and the LC resonant circuit includes a capacitor and an inductor connected in series with each other, and the capacitor is connected to the input port. Arranged on the port side and the inductor is arranged on the output port side,
Each of the capacitor and the inductor is a chip-like element, and is mounted on the surface of the circuit board and electrically connected to each other via a strip line provided on the circuit board.
A nonreciprocal circuit device characterized by the above. With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
First and second center electrodes disposed in an insulated state intersecting with the ferrite;
A circuit board holding the permanent magnet and the ferrite;
With
The first center electrode has one end electrically connected to the input port and the other end electrically connected to the output port;
The second center electrode has one end electrically connected to the output port and the other end electrically connected to the ground port.
A first matching capacitor is electrically connected between the input port and the output port;
A second matching capacitor is electrically connected between the output port and the ground port;
A resistor is electrically connected between the input port and the output port,
An LC resonant circuit is electrically connected in series with the resistor between the input port and the output port, and the LC resonant circuit includes one capacitor and two inductors electrically connected to both sides of the capacitor. And consist of
Each of the capacitor and the inductor is a chip-like element, and is mounted on the surface of the circuit board and electrically connected to each other via a strip line provided on the circuit board.
A nonreciprocal circuit device characterized by the above. With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
First and second center electrodes disposed in an insulated state intersecting with the ferrite;
A circuit board holding the permanent magnet and the ferrite;
With
The first center electrode has one end electrically connected to the input port and the other end electrically connected to the output port;
The second center electrode has one end electrically connected to the output port and the other end electrically connected to the ground port.
A first matching capacitor is electrically connected between the input port and the output port;
A second matching capacitor is electrically connected between the output port and the ground port;
A resistor is electrically connected between the input port and the output port,
An LC resonant circuit is electrically connected in series with the resistor between the input port and the output port, and the LC resonant circuit includes one inductor and two capacitors electrically connected to both sides of the inductor. And consist of
Each of the inductor and the capacitor is a chip-like element, mounted on the surface of the circuit board and electrically connected to each other via a strip line provided on the circuit board;
A nonreciprocal circuit device characterized by the above.

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