JP4665786B2 - Non-reciprocal circuit device and communication device - Google Patents

Description

  The present invention relates to a nonreciprocal circuit element, and more particularly to a nonreciprocal circuit element such as an isolator used in a microwave band and a communication apparatus.

  Conventionally, nonreciprocal circuit elements such as isolators have a characteristic of transmitting a signal only in a predetermined 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.

  Patent Document 1 describes a two-port non-reciprocal circuit device including the equivalent circuit shown in FIG. 6 as an isolator having a good insertion loss characteristic. In this isolator, substantially square ferrites and permanent magnets on which first and second center electrodes are formed are arranged (horizontal arrangement) in such a manner that their main surfaces are stacked in parallel with the surface of the circuit board.

  However, since the isolator requires a certain thickness of the permanent magnet, there is a problem that when the ferrite and the permanent magnet are stacked (horizontally arranged), the low profile is impaired. Moreover, since the substantially square ferrite and permanent magnet are used, the problem that the shape of planar view will become large also remains.

Furthermore, in this type of isolator, it is necessary to match the input impedance with the circuit to be connected. However, in the isolator, when the ferrite is rectangular in order to reduce the size and the second center electrode is wound around the ferrite multiple times, the input impedance is equal to the intersection angle between the first center electrode and the second center electrode. It turns out that it depends heavily.
JP 2005-20195 A

  Accordingly, an object of the present invention is to achieve a low profile, to set the crossing angle of the first and second center electrodes as small as possible, to reduce the input impedance, and to be irreversible with low insertion loss. A circuit element and a communication device are provided.

In order to achieve the above object, a non-reciprocal circuit device according to the present invention comprises:
With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
A first central electrode disposed on the ferrite, having one end electrically connected to the input port and the other end electrically connected to the output port;
The first center electrode is electrically insulated and intersects at a predetermined angle and is disposed on the ferrite, with one end electrically connected to the output port and the other end electrically connected to the ground port. Two center electrodes;
A first matching capacitor electrically connected between the input port and the output port;
A second matching capacitor electrically connected between the output port and the ground port;
A resistor electrically connected between the input port and the output port;
A circuit board having a connection terminal electrode formed on the surface,
Each of the ferrite and the permanent magnet is disposed on the surface of the circuit board, and a pair of principal surfaces of the ferrite and the permanent magnet are arranged in a direction substantially perpendicular to the surface.
A first recess and a second recess facing the pair of main surfaces are formed on an upper surface and a lower surface perpendicular to the pair of main surfaces of the ferrite, and a conductor is provided in the first and second recesses,
The second center electrode is spirally wound on a pair of main surfaces of the ferrite by a conductor film electrically connected via a conductor of the second recess,
The first center electrode is formed on a pair of main surfaces of the ferrite by a conductor film electrically connected to the second center electrode via an insulating film and via the conductor of the first recess. And
The other end of the first center electrode and one end of the second center electrode are electrically connected via the conductor of the first recess,
A portion of the first center electrode overlaps with a conductor provided in a second recess constituting the second center electrode via the insulating film ;
It is characterized by.

  In the nonreciprocal circuit device according to the present invention having the above-described configuration, the first recess and the second recess facing the pair of main surfaces are formed on the upper and lower surfaces orthogonal to the pair of main surfaces of the ferrite, and the first And the second recess is provided with a conductor, and the second center electrode is spirally wound around a pair of main surfaces of the ferrite by a conductor film electrically connected via the conductor of the second recess. The first center electrode is formed on a pair of main surfaces of ferrite by a conductor film electrically connected to the second center electrode via an insulating film and a conductor of the first recess. Therefore, the first center electrode can be arranged on the ferrite without being affected by the shape of the second center electrode, which means that the crossing angle of the first and second center electrodes is low even if the ferrite is short. Can be set in a large range, and input The matching of impedance can take easier, thereby preventing the deterioration of insertion loss. In other words, since the intersection angle can be set to a small value, the impedance can be kept low.

  In the nonreciprocal circuit device according to the present invention, the center electrode includes a first center electrode having one end connected to the input port and the other end connected to the output port, and is electrically insulated from the first center electrode. And a second center electrode having one end connected to the output port and the other end connected to the ground port. The first matching capacitor and the resistor are connected in parallel between the input port and the output port. Since the second matching capacitor is connected between the output port and the ground port, a two-port lumped constant isolator with low insertion loss can be obtained.

  Moreover, since the permanent magnet and the ferrite are disposed on the surface of the circuit board, and the pair of main surfaces are arranged in a direction substantially orthogonal to the surface, in other words, the ferrite and the permanent magnet are on the surface of the circuit board. Therefore, even if the permanent magnet is thickened to obtain a large magnetic field, the height does not increase regardless of the thickness, and a reduction in height is achieved.

  In the nonreciprocal circuit device according to the present invention, it is preferable that a part of the first center electrode overlaps with the conductor provided in the second recess constituting the second center electrode via an insulating film. Thereby, the crossing angle of the first and second center electrodes can be made smaller, and the input impedance can be kept low.

  Further, a third matching capacitor connected in series to the input port or the output port may be provided. This third matching capacitor can also match the input or output impedance.

  In addition, the communication device according to the present invention includes the nonreciprocal circuit element, and the impedance is well matched, and preferable electrical characteristics with low insertion loss can be obtained.

  As described above, according to the present invention, impedance matching can be easily performed even if a short ferrite is used, and it is particularly effective for lowering input impedance and has a small insertion loss. The nonreciprocal circuit device can be obtained.

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

  FIG. 1 shows an exploded perspective view of a two-port isolator which is an embodiment of a non-reciprocal circuit device according to the present invention. This two-port isolator is a lumped constant isolator, and generally includes a metal yoke 10, a cap 15, a circuit board 20, and a ferrite / magnet assembly 30 including a ferrite 32 and a permanent magnet 41. ing.

  The yoke 10 is combined with the permanent magnet 41 to form a magnetic circuit. The yoke 10 is made of a ferromagnetic material such as soft iron, is subjected to rust prevention plating, and surrounds the ferrite / magnet assembly 30 on the circuit board 20. It has a body shape. The yoke 10 is first formed as a band-like body by being punched into a separated state at the butting portion 10a, and the convex portion 11 and the concave portion 12 are strongly fitted to each other to perform a so-called crushing process to form an annular body. Is. The yoke 10 may be directly punched into a desired annular shape from a plate material approximately equal to or slightly thicker than its height.

  A cap 15 made of a dielectric (for example, resin or ceramic) is bonded to the upper surfaces of the ferrite 32 and the permanent magnet 41. A conductor is formed on the surface of the cap 15 to shield high frequencies.

  As shown in FIG. 2, the ferrite 32 is formed with a first center electrode 35 and a second center electrode 36 which 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 parallel to each other, and has upper and lower surfaces 32c and 32d and left and right end surfaces 32e and 32f.

  Further, the permanent magnet 41 is bonded via, for example, an epoxy-based adhesive sheet layer 42 so as to apply a magnetic field to the main surfaces 32a and 32b of the ferrite 32 in a direction substantially perpendicular to the main surfaces 32a and 32b. The ferrite-magnet assembly 30 is formed. The main surface 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 facing each other so that their external shapes match.

  As shown in FIG. 2, the first center electrode 35 is formed on the first main surface 32a of the ferrite 32 from the lower right and is inclined to the upper left at a relatively small angle with respect to the long side, and rises to the upper left. A connection formed around the second main surface 32b via the relay electrode 35a on the upper surface 32c and overlapping the first main surface 32a in a transparent state on the second main surface 32b, with one end formed on the lower surface 32d. It is connected to the electrode 35b. The other end of the first center electrode 35 is connected to a connection electrode 35c formed on the lower side 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 31 (refer FIG. 5) between them.

  First, the second center electrode 36 is formed in a state where the 0.5th turn 36a is inclined at a predetermined angle on the first main surface 32a and intersects the first center electrode 35, and the relay electrode 36b on the side surface 32c is formed. The first turn 36c is formed so as to intersect the first central electrode 35 on the second main surface 32b. The lower end of the first turn 36c goes around the first main surface 32a via the relay electrode 36d on the lower surface 32d, and the 1.5th turn 36e is parallel to the 0.5th turn 36a on the first main surface 32a. The first central electrode 35 is formed so as to intersect with 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, and the third turn 36k 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 36l 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.

  That is, the second center electrode 36 is wound around the ferrite 32 in a spiral manner for three turns. Here, the number of turns is calculated by assuming that the state in which the center electrode 36 crosses the first or second main surface 32a, 32b once each is 0.5 turns. The adjustment of the crossing angle α, the input impedance, and the insertion loss of the center electrodes 35 and 36 will be described later.

  The shapes of the first and second center electrodes 35 and 36 can be variously changed. For example, the first center electrode 35 may be bifurcated on the main surfaces 32 a and 32 b of the ferrite 32. Further, the number of turns of the second center electrode 36 may be 2 turns, 4 turns, and 5 turns.

  Further, the connection electrodes 35b, 35c, 36l and the relay electrodes 35a, 36b, 36d, 36f, 36h, 36j are a first recess 37a and a second recess 37b formed on the upper and lower surfaces 32c, 32d of the ferrite 32 (FIG. 3). Reference) is filled with an electrode conductor. 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.

  In the present embodiment, the second center electrode 36 is formed by a conductor film connected to the principal surfaces 32a, 32b of the ferrite 32 via relay electrodes 36b, 36d, 36f, 36h, 36j provided in the second recess 37b. ing. The first center electrode 35 is connected to the main surfaces 32a and 32b of the ferrite 32 via the insulating film 31 and the relay electrode 35a provided in the first recess 37a. It is formed of a conductor film.

  The manufacturing process will be described with reference to FIG. First, after forming a through hole in a mother ferrite substrate and filling it with an electrode conductor, various electrodes are formed by cutting the through hole at a position where it is divided. The various electrodes may be formed as conductor films in the recesses 37a, 37b, and 38. Next, the 0.5th turn 36a, the 1.5th turn 36e, and the 2.5th turn 36i of the second center electrode are formed on the main surface 32a of the ferrite 32. Then, the insulating film 31 is formed on the main surface 32 a of the ferrite 32 so as to cover the second center electrode 36. Note that two cutout portions 31 a for connecting the first central electrode 35 are formed in the insulating film 31. Next, the first center electrode 35 is formed on the insulating film 31.

  5 shows the main surface 32a of the ferrite 32, the first and second center electrodes 35 and 36 are formed on the other main surface 32b in the same manner as described above.

  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 of silver or a silver alloy by a method such as printing, transfer, or photolithography. A thick glass dielectric film can be used as the insulating film 31 of the center electrodes 35 and 36. The permanent magnet 41 is typically a strontium-based, barium-based, or lanthanum-cobalt-based ferrite magnet.

  The circuit board 20 is a laminated substrate obtained by forming predetermined electrodes on a plurality of dielectric sheets, laminating them, and sintering them. As shown in FIG. 6, matching capacitors C1, C2 , Cs1, Cs2, and termination resistor R are incorporated. Terminal electrodes 25a to 25e are formed on the front surface, and external connection terminal electrodes 26, 27, and 28 are formed on the back surface, respectively.

  The connection relationship between these matching circuit elements and the first and second center electrodes 35 and 36 will be described with reference to the equivalent circuits of FIGS. The equivalent circuit shown in FIG. 7 shows a basic first circuit example in the non-reciprocal circuit device (two-port isolator) according to the present invention, and the equivalent circuit shown in FIG. 8 shows a second circuit example. FIG. 6 shows the configuration of the second circuit example shown in FIG.

  That is, the external connection terminal electrode 26 formed on the back surface of the circuit board 20 functions as the input port P1, and this terminal electrode 26 is connected to the matching capacitor C1 and the terminal resistor R via the matching capacitor Cs1 21a. It is connected to the. The connection point 21 a is connected to one end of the first center electrode 35 via a terminal electrode 25 a formed on the surface of the circuit board 20 and a connection electrode 35 b formed on the lower surface 32 d of the ferrite 32.

  The other end of the first center electrode 35 and one end of the second center electrode 36 are connected to a termination resistor R via a connection electrode 35 c formed on the lower surface 32 d of the ferrite 32 and a terminal electrode 25 b formed on the surface of the circuit board 20. And capacitors C1 and C2.

  On the other hand, the external connection terminal electrode 27 formed on the back surface of the circuit board 20 functions as the output port P2, and this electrode 27 is connected to the connection point 21b between the capacitors C2 and C1 and the termination resistor R via the matching capacitor Cs2. It is connected.

  The other end of the second center electrode 36 is formed on the back surface of the capacitor C2 and the circuit board 20 via the connection electrode 36l formed on the lower surface 32d of the ferrite 32 and the terminal electrode 25c formed on the surface of the circuit board 20. The external connection terminal electrode 28 is connected. The external connection terminal electrode 28 functions as the ground port P3. The external connection terminal electrode 28 is also connected to the yoke 10 via terminal electrodes 25d and 25e formed on the surface of the circuit board 20.

  The circuit board 20 and the yoke 10 are integrated by soldering via terminal electrodes 25d and 25e and other dummy electrodes. The ferrite / magnet assembly 30 is integrated by soldering various electrodes on the lower surface 32d of the ferrite 32 to the terminal electrodes 25a, 25b, 25c on the circuit board 20 and other dummy terminal electrodes. The lower surface is integrated on the circuit board 20 with an adhesive. As this adhesive, a thermosetting one-component or two-component epoxy adhesive is suitable. That is, by using both soldering and adhesion for joining the ferrite / magnet assembly 30 and the circuit board 20, the joining is ensured.

  As the circuit board 20, a fired mixture of glass and alumina or another dielectric, or a composite board made of resin or glass and another dielectric is used. For the internal and external electrodes, a thick film of silver or silver alloy, a copper thick film, a copper foil, or the like is used. In particular, the electrode for external connection is preferably plated with gold and then plated with gold. This is to prevent rust prevention, improvement of resistance to solder erosion, and strength reduction of the solder joint itself due to various causes.

  In the two-port isolator configured as described above, one end of the first center electrode 35 is connected to the input port P1, the other end is connected to the output port P2, and one end of the second center electrode 36 is connected to the output port P2. The other end is connected to the ground port P3. Furthermore, since the matching capacitor C1 and the terminating resistor R are connected in parallel between the input port P1 and the output port P2, and the matching capacitor C2 is connected between the output port P2 and the ground port P3, Since only the resonant circuit of the capacitor C1 and the resistor R resonates during signal transmission, a two-port lumped constant isolator with low insertion loss can be obtained.

  The upper surface 32c and the lower surface 32d orthogonal to the pair of main surfaces 32a and 32b of the ferrite 32 are formed with recesses 37a and 37b facing the main surfaces 32a and 32b, and electrodes are provided in the recesses 37a and 37b. The two center electrodes 36 are spirally wound on the main surfaces 32 a and 32 b of the ferrite 32 by a conductor film electrically connected through the electrodes of the recesses 37 b, and the first center electrode 35 is the main center of the ferrite 32. Since the second central electrode 36 is formed on the surfaces 32a and 32b with a conductive film electrically connected to the second central electrode 36 through the insulating film 31 and through the electrode of the recess 37a, The first center electrode 35 can be disposed on the ferrite 32 without being affected by the shape, which means that the first and second center electrodes 35, 3 can be used even if the ferrite 32 is short. Means that the intersection angle α be set over a wide range, can take facilitate matching of input impedance, it is possible to prevent deterioration of the insertion loss. In other words, since the intersection angle α can be set to a small value, the impedance can be kept low.

  Here, the intersection angle α of the center electrodes 35 and 36 will be described. When the crossing angle α is changed, the susceptance part can be changed without changing the conductance part of the admittance at the input port P1 in FIG. 7, and therefore the input impedance moves on the Smith diagram of FIG. . As the crossing angle α decreases, the susceptance part of the admittance moves in the negative direction at the center frequency of the passband, and as the crossing angle α increases, the susceptance part of the admittance increases at the center frequency of the passband. Move in the direction of. By utilizing this fact, in the nonreciprocal circuit device (isolator) according to the present invention, the settable range of the crossing angle α is increased and the crossing angle α is changed to facilitate matching of the input impedance. .

  When the ferrite 32 and the permanent magnet 41 are placed vertically on the circuit board 20 to reduce the height of the isolator, as shown in FIGS. 9 and 10, when the center electrodes 35 and 36 are provided on the ferrite 32, the main surface It is conceivable that the first center electrode 35 is formed on 32 a and 32 b and the second center electrode 36 is formed via the insulating film 31. However, in this case, as shown in the third row of FIG. 10, in order to ensure insulation between the first center electrode 35 and the relay electrodes 36j, 36d of the second center electrode 36, etc. It is necessary to form the center electrode 35 at a position separated from the relay electrodes 36j and 36d, which increases the crossing angle α. If the height h of the ferrite 32 is increased, the crossing angle α can be decreased, but this cannot achieve a reduction in the height of the isolator.

  Therefore, in this embodiment, the second center electrode 36 is formed directly on the surface of the ferrite 32, and the first center electrode 35 is formed thereon via the insulating film 31. With this configuration, as shown by the dotted line in FIG. 4, even if the first center electrode 35 and the relay electrodes 36j and 36d of the second center electrode 36 overlap each other, there is no possibility of short circuit because the insulating film 31 is interposed. Therefore, the settable range of the crossing angle α can be increased, and the input impedance can be easily matched.

  Although the first center electrode 35 and the relay electrodes 36j and 36d do not necessarily overlap, if they are arranged so as to overlap, the crossing angle α can be made smaller despite the low profile of the ferrite 32. Thus, the input impedance can be kept low.

  As described above, when trying to achieve a reduction in size and height of the isolator, the ferrite 32 inevitably decreases in size, and if the center electrodes 35 and 36 are simply reduced in size, particularly the inductance of the second center electrode 36 is obtained. The value becomes smaller and the insertion loss is degraded. In the present embodiment, the second central electrode 36 is spirally wound around the main surfaces 32a and 32b of the rectangular parallelepiped ferrite 32 via the upper and lower surfaces 32c and 32d, thereby increasing the inductance value of the second central electrode 36. is doing. However, in this case, the input / output impedance may be higher than the impedance 50Ω of a normal circuit. The fact that the setting range of the crossing angle α is large and the crossing angle α can be reduced has the advantage that the input impedance thus increased can be suppressed.

  Hereinafter, the matching of input impedance will be specifically described. In order to reduce the input impedance, a capacitor Cs1 is connected in series to the input port P1 side as shown in FIG. Specifically, the intersection angle α is reduced, and the susceptance portion of the admittance at the connection point 21a in FIG. 8 is moved from the point A in FIG. 11B to the point B (negative direction) at the center frequency of the pass band. And make the resistance part of the input impedance 50Ω. Next, the impedance reactance part is set to 0Ω by the capacitor Cs1 connected in series (moving from the point B to the point O) to match the input impedance. If impedance matching is performed by connecting inductances in parallel, the crossing angle α is increased and moved from point A to point C, and the impedance is 50 Ω (from point C to point O) by the parallel connection inductance. Move. However, since the inductance has a large value, the Q is poor and the insertion loss increases, so that it is inappropriate as a matching element. Therefore, it is preferable to match the input impedance by inserting a capacitor Cs1 connected in series. In this way, by reducing the crossing angle α and adding the capacitor Cs1, it is possible to suppress the input impedance that has been increased due to the downsizing and low profile of the ferrite 32.

  When the output impedance is higher than 50Ω, as shown in FIG. 8, a capacitor Cs2 is connected in series on the output port P2 side to achieve impedance matching. In the nonreciprocal circuit device according to the present invention, the output impedance is hardly affected by the crossing angle α.

  In the present embodiment, the circuit board 20 is a multilayer dielectric substrate. As a result, a circuit network such as a capacitor and an inductor can be built inside, and the miniaturization and thinning of the isolator can be achieved, and the connection between the circuit elements is performed within the substrate, so that improvement in reliability is expected. it can. Of course, the circuit board 20 does not necessarily have to be a multilayer, and may be a single layer, and a matching capacitor or the like may be externally attached as a chip type.

(Communication device, see FIG. 12)
Next, a mobile phone will be described as an example of the communication device according to the present invention.

  FIG. 12 is an electric circuit block diagram of the RF portion of the mobile phone 220. In FIG. 12, 222 is an antenna element, 223 is a duplexer, 231 is a transmission side isolator, 232 is a transmission side amplifier, 233 is a band pass filter for transmission side stages, 234 is a transmission side mixer, 235 is a reception side amplifier, 236 is A reception side interstage bandpass filter, 237 is a reception side mixer, 238 is a voltage controlled oscillator (VCO), and 239 is a local bandpass filter.

  Here, the two-port isolator can be used as the transmission-side isolator 231. By mounting this isolator, it is possible to contribute to a reduction in size and height and obtain favorable electrical characteristics.

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

  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. The dummy recess 38 is not always necessary.

It is a disassembled perspective view which shows one Example of the nonreciprocal circuit device (2 port type isolator) based on this invention. It is a perspective view which shows the ferrite with a center electrode. It is a perspective view which shows a ferrite. It is a front view which shows the ferrite with a center electrode. It is process explanatory drawing which forms a center electrode in the main surface of a ferrite. It is a block diagram which shows the circuit structure in a circuit board. It is an equivalent circuit diagram showing a first circuit example of a 2-port isolator. It is an equivalent circuit diagram showing a second circuit example of a 2-port isolator. It is a front view which shows the ferrite with a center electrode as a comparative example. It is process explanatory drawing which forms a center electrode in the main surface of the ferrite as a comparative example. It is a Smith chart which shows the change of input impedance. It is a block diagram which shows one Example of the communication apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Circuit board 25a-25c ... Terminal electrode 30 ... Ferrite magnet assembly 31 ... Insulating film 32 ... Ferrite 32a, 32b ... Main surface 35 ... 1st center electrode 35a, 36b, 36d, 36f, 36h, 36j ... For relay Electrode 36 ... 2nd center electrode 37a, 37b ... Recess 41 ... Permanent magnet 220 ... Mobile phone α ... Crossing angle P1 ... Input port P2 ... Output port P3 ... Ground port C1, C2, Cs1, Cs2 ... Capacitor R ... Termination resistance

Claims (3)

With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
A first central electrode disposed on the ferrite, having one end electrically connected to the input port and the other end electrically connected to the output port;
The first center electrode is electrically insulated and intersects at a predetermined angle and is disposed on the ferrite, with one end electrically connected to the output port and the other end electrically connected to the ground port. Two center electrodes;
A first matching capacitor electrically connected between the input port and the output port;
A second matching capacitor electrically connected between the output port and the ground port;
A resistor electrically connected between the input port and the output port;
A circuit board having a connection terminal electrode formed on the surface,
Each of the ferrite and the permanent magnet is disposed on the surface of the circuit board, and a pair of principal surfaces of the ferrite and the permanent magnet are arranged in a direction substantially perpendicular to the surface.
A first recess and a second recess facing the pair of main surfaces are formed on an upper surface and a lower surface perpendicular to the pair of main surfaces of the ferrite, and a conductor is provided in the first and second recesses,
The second center electrode is spirally wound on a pair of main surfaces of the ferrite by a conductor film electrically connected via a conductor of the second recess,
The first center electrode is formed on a pair of main surfaces of the ferrite by a conductor film electrically connected to the second center electrode via an insulating film and via the conductor of the first recess. and,
The other end of the first center electrode and one end of the second center electrode are electrically connected via the conductor of the first recess,
A portion of the first center electrode overlaps with a conductor provided in a second recess constituting the second center electrode via the insulating film ;
A nonreciprocal circuit device characterized by the above. The nonreciprocal circuit device according to claim 1, further comprising a third matching capacitor connected in series to the input port or the output port. Communication apparatus comprising the nonreciprocal circuit device according to claim 1 or claim 2.

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