JP2007306148A - Nonreciprocal circuit element and communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonreciprocal circuit element capable of obtaining an excellent insertion loss characteristic and effectively suppressing harmonics (second harmonic and third harmonic) without the need for using a trap inductance and to provide a communication apparatus. <P>SOLUTION: The nonreciprocal circuit element (2-port type isolator) comprises a microwave ferrite 32, first and second center electrodes 35, 36 in crossing on the ferrite 32 while being isolated with each other, and a permanent magnet for applying a DC magnetic field to the ferrite 32. One end of the first center electrode 35 is connected to an input port P1 and the other end is connected to an output port P2. One end of the second center electrode 36 is connected to the output port P2. A tap electrode 37 is connected to a prescribed part of the second center electrode 36, and the tap electrode 37 is connected to a ground port P3. Further, a parallel circuit comprising a first matching capacitor C1 and a resistor R is connected between the input port P1 and the output port P2, and a second matching capacitor C2 is connected between the other end of the center electrode 36 and the output port P2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a non-reciprocal circuit element, in particular, a non-reciprocal circuit element used as a two-port isolator used in a microwave band, and a communication apparatus including the non-reciprocal circuit element.

  Conventionally, non-reciprocal circuit elements such as isolators and circulators have a characteristic of transmitting signals only in a predetermined direction and not transmitting in the reverse direction, and are used in mobile communication devices such as automobile phones and mobile phones. Used in the transmission circuit section. As this kind of non-reciprocal circuit device, a two-port type is described in, for example, Patent Documents 1 and 2.

  Patent Document 1 discloses a 2-port isolator having an equivalent circuit shown in FIG. That is, a parallel circuit including first and second center electrodes 335 and 336 magnetically coupled by a ferrite 331, and a first matching capacitor C1 and a resistor R between the input port P1 and the output port P2. Are electrically connected in parallel with the first center electrode 335, and further, a parallel resonant circuit comprising a second center electrode 336 and a second matching capacitor C2 between the output port P2 and the ground port P3, and An inductance 337 is connected in series.

  In this two-port isolator, when a signal propagates from the input port P1 to the output port P2, the resonance circuit composed of the first center electrode 335 and the first matching capacitor C1 does not resonate. Become good. Further, the circuit composed of the LC parallel resonance circuit and the series inductance 337 forms a trap circuit, and the attenuation pole is formed between the second harmonic and the third harmonic. As a result, it is possible to increase the attenuation amount of the second harmonic or the third harmonic of the use frequency propagating through the first center electrode 335 without deteriorating the insertion loss.

  However, in this isolator, harmonics can be attenuated. However, since the second center electrode 336 is provided only on one surface of the ferrite 331, the second center is used although a large ferrite is used. The inductance value of the electrode 336 is small and the Q is also low. As a result, the operation band is narrow and the insertion loss is not satisfactory. Further, since the trapping inductance 337 is provided, the number of parts increases.

On the other hand, the isolator described in Patent Document 2 can increase the inductance value of the second center electrode 336 while using a small ferrite by winding the second center electrode 336 around the ferrite a plurality of turns. Insertion loss can be reduced. However, since the inductance value of the second center electrode 336 is large, the capacitance value of the second matching capacitor C2 becomes small, and accordingly, the value of the trapping inductance 337 needs to be increased. When the value of the inductance 337 is increased, both the attenuation amount and the attenuation width that can be attenuated are decreased.
JP 2004-88744 A International Publication No. 2006/11382 Pamphlet

  Accordingly, an object of the present invention is a non-reciprocal circuit device capable of obtaining good insertion loss characteristics and effectively suppressing harmonics (second harmonics and third harmonics) without using trapping inductances. And providing a communication device including the nonreciprocal circuit device.

In order to achieve the above object, a non-reciprocal circuit device according to a first invention is
With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
A first center electrode disposed on the ferrite, having one end electrically connected to the input port and the other end electrically connected to the output port;
A second center electrode that is disposed in electrical insulation with the first center electrode, wound around the ferrite for one or more turns, and has one end electrically connected to the output port;
A tap electrode electrically connected to a predetermined location of the second center electrode and electrically connected to the ground;
A parallel circuit including a first matching capacitor and a resistor electrically connected between the input port and the output port;
A second matching capacitor electrically connected between the other end of the second center electrode and the output port;
It is provided with.

The non-reciprocal circuit device according to the second invention is
A permanent magnet made of a rectangular parallelepiped;
A ferrite composed of a rectangular parallelepiped to which a DC magnetic field is applied by the permanent magnet;
A first center electrode formed of an electrode film on the ferrite, having one end electrically connected to the input port and the other end electrically connected to the output port;
Crossed with the first center electrode in an electrically insulated state and formed by winding the ferrite around the axis parallel to the long side of the ferrite by an electrode film for at least one turn, and one end electrically connected to the output port A second center electrode,
A tap electrode formed by an electrode film on the ferrite and electrically connected to a predetermined location of the second center electrode and electrically connected to the ground;
A parallel circuit including a first matching capacitor and a resistor electrically connected between the input port and the output port;
A second matching capacitor electrically connected between the other end of the second center electrode and the output port;
A circuit board having a connection electrode for electrically connecting to the first center electrode, the second center electrode and the tap electrode, and holding the permanent magnet and the ferrite;
It is provided with.

  In the nonreciprocal circuit device according to the first and second inventions, the tap electrode connected to a predetermined location of the second center electrode is connected to the ground, and a part of the second center electrode and the second matching capacitor are used. The harmonic frequency of the second harmonic or the third harmonic is effectively suppressed by using the resonance frequency of the resonance circuit as a trap frequency. Further, when a signal propagates from the input port to the output port, a potential difference is generated between both ends of the resonance circuit including the first center electrode and the first matching capacitor due to the action of the irreversible phase shifter including the ferrite and the center electrode. Of course, no resonance current flows and no insertion loss characteristic is obtained.

  In the nonreciprocal circuit device according to the first and second inventions, an inductance may be electrically connected between the tap electrode and the ground. With this inductance, the frequency of series resonance with the second matching capacitor can be finely adjusted to obtain a desired attenuation frequency characteristic.

  A parallel circuit of an inductance and a third matching capacitor may be electrically connected between the tap electrode and the ground. A desired frequency signal in the harmonic frequency band can be greatly attenuated by series resonance between a part of the second center electrode and the third matching capacitor.

  Further, another matching capacitor may be electrically connected between the input port and the first center electrode and / or between the output port and the connection point of the first and second center electrodes. . Impedance matching with a device connected to the nonreciprocal circuit device can be achieved with another matching capacitor. In addition, since the operating impedance of the main circuit portion closer to the ferrite than these matching capacitors is increased, the effect of unnecessary signal attenuation by the series resonance trap can be further enhanced.

  In the nonreciprocal circuit device according to the second invention, the principal surfaces of the permanent magnet and the ferrite may be arranged perpendicular to the surface of the circuit board. By arranging the permanent magnet and the ferrite vertically on the circuit board, it is possible to reduce the height even if a thick (strong magnetic force) permanent magnet is used, and the nonreciprocal circuit element can be reduced in size.

  The circuit board is preferably a multilayer board, and the first matching capacitor, the resistor, and the second matching capacitor are preferably built in the multilayer board by an electrode film. If each element is built in the multilayer substrate, it is easy to assemble by eliminating the trouble of connecting each element with solder or the like, the connection reliability is good, and the height and size are reduced.

  A communication apparatus according to the present invention includes the non-reciprocal circuit element, and a communication apparatus using a good insertion loss characteristic and harmonic attenuation characteristic, which are advantages of the non-reciprocal circuit element, can be obtained.

  According to the present invention, since the tap electrode connected to the predetermined position of the second center electrode is connected to the ground, the resonance frequency of the resonance circuit including a part of the second center electrode and the second matching capacitor is used as the trap frequency. The harmonics of the second harmonic and the third harmonic can be effectively suppressed, and it is not necessary to use a special inductor. In addition, when the signal propagates from the input port to the output port, the resonance circuit composed of the first center electrode and the first matching capacitor does not resonate, so that the insertion loss characteristic is improved. Since the center electrode in the isolator is a very high inductor, it is possible to obtain unnecessary wave attenuation while suppressing the insertion loss of the in-band signal to be passed.

  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.

(Refer to the first embodiment of the nonreciprocal circuit device, FIGS. 1 to 6)
FIG. 1 shows a nonreciprocal circuit device according to a first embodiment of the present invention. This non-reciprocal circuit element is a two-port lumped constant type isolator, and generally includes a shield plate 10, a yoke 20, a ferrite / magnet assembly 30, and a circuit board 40.

  The ferrite-magnet assembly 30 is obtained by bonding permanent magnets 31, 31 made of a rectangular parallelepiped and ferrite 32 made of a rectangular parallelepiped to which a DC magnetic field is applied from the permanent magnet with adhesive layers 33, 33. A first center electrode 35 and a second center electrode 36 are formed of electrode films on the surface. The ferrite / magnet assembly 30 is mounted on the circuit board 40 in a connected state as described below, and is surrounded by the yoke 20 and the shield plate 10.

  The ferrite 32 is provided 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. The ferrite 32 has a rectangular parallelepiped shape having a first main surface 32a and a second main surface 32b that are parallel to each other. Further, the permanent magnets 31, 31 are opposed to the main surfaces 32 a, 32 b of the ferrite 32 through the adhesive layer 33 with the main surfaces 31 a facing each other so as to apply a magnetic field in a direction perpendicular to the main surfaces 32 a, 32 b. It is integrated.

  As shown in FIG. 2, the first center electrode 35 rises from the lower right on the main surface 32a of the ferrite 32 and extends in the upper left direction in a state of branching into two, via the relay electrode 35a on the upper surface 32c. The main surface 32b diverges into two so as to overlap the main surface 32a in a transparent state on the main surface 32b, and 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.

  The second center electrode 36 is wound around the ferrite 32 for four turns around an axis parallel to its long side. That is, the 0.5th turn 36a extends from the lower side to the upper left direction on the main surface 32a so as to intersect the first center electrode 35, and wraps around the main surface 32b via the relay electrode 36b on the upper surface 32c. The turn 36c extends vertically downward on the main surface 32b and intersects the first center electrode 35. The lower end of the first turn 36c goes around the main surface 32a via the relay electrode 36d on the lower surface 32d, and the 1.5th turn 36e extends upward across the first central electrode 35 on the main surface 32a. The main surface 32b passes through 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. One end of the second center electrode 36 is connected to the connection electrode 35 c and the other end is connected to a connection electrode 36 p formed on the lower surface of the ferrite 32.

  Furthermore, the relay electrode 36h of the second center electrode 36 functions as a tap electrode 37 as described below.

  The first and second center electrodes 35 and 36 are formed of a conductive film by screen printing, transferring, or photolithography using a silver paste on the surface of the ferrite 32. The ferrite 32 may be multilayered and formed inside with a conductor film. In addition, you may wind around the ferrite 32 using copper foil. Since the position accuracy of the center electrodes 35 and 36 is higher when the conductive film is formed, the connectivity with the circuit board 40 is more stable, and the connection reliability and workability are better. The first center electrode 35 and the second center electrode 36 are insulated from each other by forming an insulating film made of glass or the like therebetween.

  A ferrite magnet is used as the permanent magnet 31, and the ferrite 32 is protected by sandwiching the ferrite 32 between the permanent magnets 31, 31.

  The circuit board 40 is a multilayer board obtained by forming predetermined electrodes on a plurality of dielectric sheets, laminating them, and sintering them. Inside the circuit board 40, as shown in FIG. 3, matching capacitors C1, C2, C3 , CS1, CS2, CP1, CP2, termination resistor R, and inductance L3. Further, terminal electrodes 45a to 45e are formed on the upper surface, and external connection terminal electrodes 46, 47, and 48 are formed on the lower surface, respectively.

  For the dielectric sheet of the circuit board 40, a dielectric made of ceramic powder such as glass and alumina that can be fired simultaneously with various electrodes constituting the circuit element is used as a raw material. It is also possible to use a resin substrate such as glass epoxy resin or glass BT resin, or a material obtained by adding dielectric powder such as ceramic to a resin material. A copper foil may be used for the electrode. The terminal electrodes 45a to 45e and the external connection terminal electrodes 46, 47 and 48 are plated with nickel or gold.

  A connection relationship between the matching circuit element and the first and second center electrodes 35 and 36 will be described with reference to FIGS. 4, 5, and 6. FIG. 3 shows the configuration of the third circuit example shown in FIG.

  That is, the external connection terminal electrode 46 formed on the lower surface of the circuit board 40 functions as the input port P1, the external connection terminal electrode 47 functions as the output port P2, and the external connection terminal electrode 48 functions as the ground port P3. Function. Then, the connection electrode 35 b which is one end of the first center electrode 35 is connected to the terminal electrode 45 a formed on the upper surface of the circuit board 40. The connection electrode 35 c that is the other end of the first center electrode 35 and one end of the second center electrode 36 is connected to a terminal electrode 45 b formed on the upper surface of the circuit board 40. The connection electrode 36p, which is the other end of the second center electrode 36, is connected to a terminal electrode 45c formed on the upper surface of the circuit board 40. The relay electrode 36 h (tap electrode 37) of the second center electrode 36 is connected to a terminal electrode 45 d formed on the upper surface of the circuit board 40.

(First circuit example, see FIGS. 4 and 9)
In the first circuit example, as shown in FIG. 4, one end of the first center electrode 35 is connected to the input port P1 via the matching capacitor CS1, and the other end is connected to the output port P2 via the matching capacitor CS2. It is connected. One end of the second center electrode 36 is connected to the other end of the first center electrode 35. A parallel circuit composed of the matching capacitor C1 and the resistor R is connected in parallel with the first center electrode 35.

  The tap electrode 37 is connected to a predetermined location (relay electrode 36h) of the second center electrode 36 and to the ground port P3. A matching capacitor C <b> 2 is connected in parallel with the second center electrode 36. Further, matching capacitors CP1 and CP2 connected to the ground port P3 are connected to the input port P1 and the output port P2.

  In the first circuit example configured as described above, the first and second center electrodes 35 and 36 form inductances L1 and L2 magnetically coupled by the ferrite 32, and a signal (fundamental frequency band: 800 MHz) is generated. When propagating from the input port P1 to the output port P2, the inductance L2 and the capacitor C2 resonate in parallel, one end (B electrode) of the second center electrode 36 becomes high impedance, and the signal whose impedance is converted by the capacitor CS2 is output to the output port P2. Is output from. In the resonance circuit composed of the inductance L1 and the capacitor C1, no resonance current flows due to the action of the nonreciprocal phase shifter, and the insertion loss is greatly reduced. In addition, the resistance R improves the isolation characteristics in the reverse direction. On the other hand, impedance matching with a device connected to the input port P1 is performed by a matching capacitor CS1.

  In the harmonic frequency band, the capacitor C2 resonates in series between the tap electrode 37 connected to a predetermined position of the second center electrode 36 from the other end (C electrode) of the inductance L2 at a desired frequency. A signal of this frequency is totally reflected by a short circuit of the B electrode to the ground due to series resonance, and is greatly attenuated.

  The electrical characteristics of this first circuit example are shown in FIG. The isolator that has obtained this characteristic has the following specifications. A first center electrode 35 is wound around the ferrite 32 having a height of 0.7 mm, a thickness of 0.14 mm, and a length of 2.1 mm, and the second center electrode 36 is wound four turns, and a tap electrode is formed at the middle point. 37 was connected. C1 is 12 pF, C2 is 1.5 pF, CS1 is 5 pF, and CS2 is 5 pF. S21 (transmission characteristics) is about -29 dB in the second harmonic band and about -13 dB in the third harmonic band, and a large attenuation is obtained.

(Refer to the second circuit example, FIGS. 5 and 10)
As shown in FIG. 5, the second circuit example is basically the same as the first circuit example, and an inductance L3 is connected between the tap electrode 37 and the ground port P3. The operation in the fundamental frequency band (800 MHz) is the same as in the first circuit example. The inductance L3 is selected to have a sufficiently small value (1/10 or less) as compared with the inductance L2, so that the operation with the fundamental wave is hardly affected.

  In the harmonic frequency band, a part of the inductance L2 and the inductance L3 and the capacitor C2 resonate in series at a desired frequency, and the frequency of the series resonance is finely adjusted by the value of the inductance L3 to obtain a desired attenuation frequency characteristic. A signal of this frequency is totally reflected by a short circuit of the B electrode to the ground due to series resonance, and is greatly attenuated.

  FIG. 10 shows the electrical characteristics of this second circuit example. The isolator having this characteristic is the same as the above-mentioned specification of the first circuit example, the inductance L3 is about 0.4 nH, and the attenuation pole frequency is matched with the third harmonic band. S21 (transmission characteristics) is about −15 dB in the second harmonic band and about −30 dB in the third harmonic band, and a large attenuation is obtained.

(Third circuit example, see FIGS. 6 and 11)
As shown in FIG. 6, the third circuit example is basically the same as the first circuit example, and a parallel circuit of an inductance L3 and a matching capacitor C3 is provided between the tap electrode 37 and the ground port P3. Connected. The operation in the fundamental frequency band (800 MHz) is the same as in the first circuit example. As the inductance L3, a value sufficiently smaller than the inductance L2 (1/10 or less) is selected as in the second circuit example. In addition, it is preferable to select a sufficiently small value (1/10 or less) for the capacitor C3 that does not significantly affect the series resonance between a part of the inductance L2 and the capacitor C2.

  In the harmonic frequency band, a part of the inductance L2 and the inductance L3 and the capacitor C2 resonate in series at a desired frequency, and the frequency of the series resonance is finely adjusted by the value of the inductance L3 to obtain a desired attenuation frequency characteristic. A signal of this frequency is totally reflected by a short circuit of the B electrode to the ground due to series resonance, and is greatly attenuated. In addition, a part of the inductance L2 and the capacitor C3 resonate in series at the second desired frequency in the harmonic frequency band. The signal of the second desired frequency is totally reflected by a short circuit of the B electrode to the ground due to series resonance, and is greatly attenuated.

  The specifications are the same as in the first circuit example, and the inductance L3 is about 0.2 nH. When the capacitor C3 was about 0 pF, the attenuation pole frequency did not coincide with the third harmonic band, and the electrical characteristics shown in FIG. 11A were obtained. Capacitor C3 is about 12 pF, and the attenuation pole frequency matches the third harmonic band. As shown in FIG. 11B, S21 (transmission characteristics) is about −18 dB in the second harmonic band and the third harmonic band. It was about -30 dB or more, and a large attenuation was obtained.

  The third circuit example is more advantageous than the first circuit example in that the attenuation pole frequency of the second harmonic is appropriately set with the value of the inductance L3, and then the attenuation pole frequency of the third harmonic is set to the capacitor C3. The value can be set appropriately.

(Refer to the second embodiment of the nonreciprocal circuit device, FIG. 7 and FIG. 8)
FIG. 7 shows a non-reciprocal circuit device according to a second embodiment of the present invention. This non-reciprocal circuit element is a two-port lumped constant isolator, as in the first embodiment, and roughly includes an upper yoke 11, a permanent magnet 31 ', a center electrode assembly 30', and a circuit board. 40 'and the lower yoke 12 are comprised.

  The center electrode assembly 30 ′ is formed by forming a first center electrode 35 ′ and a second center electrode 36 ′ with a conductor film on a ferrite 32 ′ made of a rectangular parallelepiped, and the second center electrode 36 ′ is the same as that of the first embodiment. Is wound two turns differently.

  The center electrode assembly 30 'has a main surface arranged in parallel with the surface of the circuit board 40', and a permanent magnet 31 'is stacked thereon. The circuit board 40 'is a multilayer board similar to that of the first embodiment, and various matching elements are incorporated as shown in FIG. The termination resistor R is a chip component and is mounted on the surface of the circuit board 40 '. That is, the terminal electrode 49a formed on the surface of the circuit board 40 'is connected to the connection electrode 35a' that is one end of the first center electrode 35 ', and the terminal electrode 49b is connected to the other end of the first center electrode 35'. It is connected to the electrode 35b ′ for use. The terminal electrode 49c is connected to the connection electrode 36a ′ that is one end of the second center electrode 36 ′, and the terminal electrode 49d is connected to the connection electrode 36b ′ that is the other end of the second center electrode 36 ′. . Further, a predetermined portion of the second center electrode 36 ′ is a tap electrode 37 ′ and is connected to a terminal electrode 49 e formed on the surface of the circuit board 40 ′.

  Also in the second embodiment, the circuit configuration as an isolator can employ the first to third circuit examples shown in FIGS. 4 to 6, and the operation of each circuit example will be described in the first embodiment. Just as you did. FIG. 8 shows the configuration of the third circuit example shown in FIG.

(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 shows an electric circuit of the RF part of the mobile phone 220, 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, and 234 is transmission A side mixer, 235 is a reception side amplifier, 236 is a reception side interstage band pass filter, 237 is a reception side mixer, 238 is a voltage controlled oscillator (VCO), and 239 is a local band pass filter.

  Here, the 2-port lumped constant type isolator can be used as the transmission side isolator 231. By mounting this isolator, a mobile phone using the good insertion loss characteristic and isolation characteristic of the isolator itself can be realized, which contributes to a reduction in size and height of the mobile phone.

(Other embodiments)
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, detailed configurations of the ferrite / magnet assembly 30 and the circuit board 40 are arbitrary. Further, as shown in the second embodiment, in addition to configuring the resistors with chip parts, various matching capacitors may also be configured with chip parts.

1 is an exploded perspective view showing a first embodiment of a non-reciprocal circuit device (2-port isolator) according to the present invention. It is a perspective view which shows the ferrite which comprises the 2 port type isolator which is 1st Example. It is a disassembled perspective view which shows an example of the circuit board which comprises the 2 port type isolator which is 1st Example. FIG. 3 is an equivalent circuit diagram illustrating a first circuit example of the 2-port isolator according to the first embodiment. FIG. 3 is an equivalent circuit diagram showing a second circuit example of the 2-port isolator which is the first embodiment. FIG. 3 is an equivalent circuit diagram showing a third circuit example of the 2-port isolator which is the first embodiment. It is a disassembled perspective view which shows 2nd Example of the nonreciprocal circuit device (2 port type isolator) based on this invention. It is a disassembled perspective view which shows an example of the circuit board which comprises the 2 port type isolator which is 2nd Example. 5 is a graph showing electrical characteristics of the first circuit example shown in FIG. 4. It is a graph which shows the electrical property of the 2nd circuit example shown in FIG. It is a graph which shows the electrical property of the 3rd circuit example shown in FIG. It is a block diagram which shows the electric circuit of the communication apparatus which concerns on this invention. It is an equivalent circuit diagram of a conventional 2-port type isolator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 ... Ferrite magnet assembly 31 ... Permanent magnet 32 ... Ferrite 35 ... 1st center electrode 36 ... 2nd center electrode 37 ... Tap electrode 40 ... Circuit board 220 ... Mobile phone C1 ... Capacitor for 1st matching C2 ... 2nd matching Capacitor C3 ... third matching capacitor L1, L2, L3 ... inductance R ... resistor P1 ... input port P2 ... output port P3 ... ground port

Claims (8)

With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
A first center electrode disposed on the ferrite, having one end electrically connected to the input port and the other end electrically connected to the output port;
A second center electrode that is disposed in electrical insulation with the first center electrode, wound around the ferrite for one or more turns, and has one end electrically connected to the output port;
A tap electrode electrically connected to a predetermined location of the second center electrode and electrically connected to the ground;
A parallel circuit including a first matching capacitor and a resistor electrically connected between the input port and the output port;
A second matching capacitor electrically connected between the other end of the second center electrode and the output port;
A non-reciprocal circuit device comprising: A permanent magnet made of a rectangular parallelepiped;
A ferrite composed of a rectangular parallelepiped to which a DC magnetic field is applied by the permanent magnet;
A first center electrode formed of an electrode film on the ferrite, having one end electrically connected to the input port and the other end electrically connected to the output port;
Crossed with the first center electrode in an electrically insulated state and formed by winding the ferrite around the axis parallel to the long side of the ferrite by an electrode film for at least one turn, and one end electrically connected to the output port A second center electrode,
A tap electrode formed by an electrode film on the ferrite and electrically connected to a predetermined location of the second center electrode and electrically connected to the ground;
A parallel circuit including a first matching capacitor and a resistor electrically connected between the input port and the output port;
A second matching capacitor electrically connected between the other end of the second center electrode and the output port;
A circuit board having a connection electrode for electrically connecting to the first center electrode, the second center electrode and the tap electrode, and holding the permanent magnet and the ferrite;
A non-reciprocal circuit device comprising:   The nonreciprocal circuit device according to claim 1, wherein an inductance is electrically connected between the tap electrode and the ground.   The nonreciprocal circuit device according to claim 1 or 2, wherein a parallel circuit of an inductance and a third matching capacitor is electrically connected between the tap electrode and the ground.   Another matching capacitor is electrically connected between the input port and the first center electrode and / or between the output port and the connection point of the first and second center electrodes. The non-reciprocal circuit device according to any one of claims 1 to 4, wherein   3. The nonreciprocal circuit device according to claim 2, wherein the main surfaces of the permanent magnet and the ferrite are arranged perpendicular to the surface of the circuit board.   7. The circuit board according to claim 2, wherein the circuit board is formed of a multilayer board, and the first matching capacitor, the resistor, and the second matching capacitor are built in the multilayer board by an electrode film. Non-reciprocal circuit element.   A communication apparatus comprising the nonreciprocal circuit device according to any one of claims 1 to 7.

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