WO2017150619A1

WO2017150619A1 - Irreversible circuit element, front-end circuit, and communication device

Info

Publication number: WO2017150619A1
Application number: PCT/JP2017/008125
Authority: WO
Inventors: 裕亮楠本
Original assignee: 株式会社村田製作所
Priority date: 2016-03-03
Filing date: 2017-03-01
Publication date: 2017-09-08

Abstract

This irreversible circuit element is provided with: a core section (40) having a permanent magnet (30), ferrite (25), and a first central conductor (21) having one end that is connected to a first port (Port1), a second central conductor (22) having one end that is connected to a second port (Port2), and a third central conductor (23) having one end that is connected to a third port (Port3), each being arranged so as to intersect one another in an insulated state in the ferrite (25); and an adjustment circuit (50) that is arranged on the exterior of the core section (40) and adjusts the balance between the pass characteristic from the first port (Port1) to the third port (Port3) and the pass characteristic from the third port (Port3) to the second port (Port2) in a usage frequency band.

Description

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

The present invention allows a high-frequency signal input to a first port connected to a transmission-side circuit to pass through a third port connected to an antenna-side circuit, and causes the high-frequency signal input to the third port to pass through a reception-side circuit. The present invention relates to a non-reciprocal circuit device that is passed to a second port connected to the.

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

According to this configuration, the end portions of the central conductors provided on the ferrite by printing or the like are connected to the ground potential via the inductance element and the capacitance element that are connected to each other and connected in series. By providing such an inductance element and a capacitance element, the nonreciprocal circuit element is designed to widen the pass band.

International Publication No. 2013/168771

In such a nonreciprocal circuit element, in the use frequency band of the nonreciprocal circuit element, the Tx passing characteristic from the first port connected to the transmission side circuit to the third port connected to the antenna side circuit, and the third port In order to adjust the balance with the Rx pass characteristic from the first to the second port connected to the receiving side circuit, for example, the line width and line length of the central conductor (inner conductor) arranged in the ferrite, Design parameters need to be adjusted. However, if an attempt is made to adjust the design parameters inside the core part such as the core circulator, the center electrode formed by printing or the like on the ferrite is changed, which involves a significant design change. For this reason, there is a problem that it takes much time and effort to adjust the balance between the Tx passage characteristic from the first port to the third port and the Rx passage characteristic from the third port to the second port.

Therefore, the present invention adjusts the balance between the Tx pass characteristic from the first port to the third port and the Rx pass characteristic from the third port to the second port without changing the design inside the core unit. It is an object of the present invention to provide a nonreciprocal circuit element that can be used, and a front-end circuit and a communication device having the nonreciprocal circuit element.

To achieve the above object, a nonreciprocal circuit device according to an aspect of the present invention transmits a high-frequency signal input to a first port connected to a transmission-side circuit to a third port connected to an antenna-side circuit. A non-reciprocal circuit element that passes and passes a high-frequency signal input to the third port to a second port connected to a receiving side circuit, and a DC magnetic field is applied by the permanent magnet and the permanent magnet. The ferrite and the ferrite are each arranged in an insulated state so as to cross each other, one end of the first central conductor connected to the first port, and one end connected to the second port A core portion having two center conductors and a third center conductor having one end connected to the third port; and a frequency band used for the nonreciprocal circuit device disposed outside the core portion. In the first port And a regulating circuit for adjusting the balance between the passing characteristic from said third port and pass characteristic to the third port to the second port from.

As described above, the adjustment circuit can adjust the superiority of the Tx pass characteristic from the first port to the third port and the Rx pass characteristic from the third port to the second port. Specifically, according to this aspect, the adjustment circuit that adjusts the balance between the Tx pass characteristic and the Rx pass characteristic is provided outside the core part, so that it is easy to change the design inside the core part. In addition, the balance between the Tx pass characteristic and the Rx pass characteristic can be changed.

The adjustment circuit connects the other end of the first central conductor and the ground potential, and connects the other end of the second central conductor to the ground potential. You may decide to have at least one among the shunt connection type 2nd elements.

As described above, the adjustment circuit includes a first element that connects the other end of the first center conductor and the ground potential, and a second element that connects the other end of the second center conductor and the ground potential. By having at least one of them, the balance between the Tx pass characteristic and the Rx pass characteristic can be changed without changing the design inside the core part.

The first element includes a first capacitor, the second element includes a second capacitor, and the other end of the first center conductor and the other end of the third center conductor; At least one of a first inductor that connects the second inductor and a second inductor that connects the other end of the third central conductor and the other end of the second central conductor.

Thus, since the adjustment circuit has the first capacitor as the first element, the first center conductor and the first capacitor form a shunt-connected LC series resonance circuit. Therefore, by providing the first capacitor such that the LC series resonance circuit resonates in the vicinity of the use frequency band of the nonreciprocal circuit element, the first center conductor behaves as follows. That is, when a high-frequency signal is input from the first port, the first center conductor resonates by an LC series resonance circuit formed by the first capacitor in addition to resonance due to magnetic coupling with the second center conductor. . That is, by providing the first capacitor, it is possible to cause the first center conductor to resonate. At this time, if the first inductor is provided, a potential difference is generated between the other end of the first center conductor and the other end of the third center conductor. The pass characteristic can be widened.

In other words, by providing the first capacitor, the path to the ground potential on the first center conductor side is shortened, and unnecessary inductance components can be reduced. For this reason, the Tx pass characteristic can be widened.

Note that the second capacitor and the second inductor can also widen the Rx pass characteristic by a mechanism similar to that of the first capacitor and the first inductor.

The adjustment circuit may include only the first capacitor of the first capacitor and the second capacitor.

This makes it possible to balance the Tx pass characteristic over the Rx pass characteristic in the operating frequency band of the nonreciprocal circuit element.

The adjustment circuit may include only the second capacitor of the first capacitor and the second capacitor.

This makes it possible to balance the Rx pass characteristic over the Tx pass characteristic in the operating frequency band of the nonreciprocal circuit element.

The adjustment circuit may include both the first capacitor and the second capacitor, and the first capacitor may have a larger capacitance value than the second capacitor.

The adjustment circuit may include both the first capacitor and the second capacitor, and the second capacitor may have a larger capacitance value than the first capacitor.

The adjustment circuit may include both the first capacitor and the second capacitor, and the first capacitor and the second capacitor may have substantially the same capacitance value.

This makes it possible to balance the Tx pass characteristic and the Rx pass characteristic in the same frequency range in which the nonreciprocal circuit element is used.

Further, the adjustment circuit may include both the first inductor and the second inductor.

As described above, since the adjustment circuit includes both the first inductor and the second inductor, the balance between the Tx pass characteristic and the Rx pass characteristic can be easily changed only by changing the constants of the first capacitor and the second capacitor. Can do.

The nonreciprocal circuit element includes a circuit board on which the core unit is mounted and the adjustment circuit is provided, and at least one of the first inductor and the second inductor is provided on the circuit board. The first center conductor, the second center conductor, and the third center conductor may be configured by a conductor that connects the other ends of the first center conductor, the second center conductor, and the third center conductor.

Thus, since at least one of the first inductor and the second inductor is constituted by the conductor provided on the circuit board, the number of parts can be reduced.

The adjustment circuit further includes a first matching capacitor that connects one end of each of the first center conductor, the second center conductor, and the third center conductor to a ground potential, and the first matching conductor. Second matching connected in series between the port and the first central conductor, between the second port and the second central conductor, and between the third port and the third central conductor, respectively. You may decide to have a capacitor.

As described above, since the adjustment circuit includes the first matching capacitor, the pass characteristic can be widened in the use frequency band of the nonreciprocal circuit element by appropriately selecting the capacitance value of the first matching capacitor. . In addition, since the adjustment circuit includes the second matching capacitor, the impedance of the first to third ports can be easily adjusted by appropriately selecting the capacitance value of the second matching capacitor. For this reason, loss can be improved (deterioration of insertion loss is reduced).

The nonreciprocal circuit element includes a circuit board on which the core unit is mounted and the adjustment circuit is provided, and the circuit board includes a chip that constitutes each of the first element and the second element. A surface electrode for mounting a component may be provided.

As described above, the circuit board is provided with the surface electrodes for mounting the chip components constituting each of the first element and the second element. Accordingly, the first element and the second element are appropriately mounted according to the required specifications using the common core portion and the circuit board, and thereby the nonreciprocal circuit element having a balance of pass characteristics according to the specifications. Can be realized. In other words, the width of the development (reuse) of the core portion is widened, and the cost can be reduced.

Further, the present invention can be realized not only as the above-described non-reciprocal circuit element but also as a front-end circuit including the non-reciprocal circuit element. In other words, in order to achieve the above object, a front-end circuit according to an aspect of the present invention includes a nonreciprocal circuit element, a transmission-side circuit connected to the first port, and a reception connected to the second port. A side circuit and an antenna terminal connected to the third port.

According to such a front-end circuit, a desired pass characteristic can be realized by providing the nonreciprocal circuit element having a balance between the Tx pass characteristic and the Rx pass characteristic according to the required specifications.

Further, a switch circuit for selectively connecting the second port and the receiving circuit may be provided.

Thereby, it is possible to suppress the wraparound of the high frequency signal to the receiving side circuit during transmission.

Further, the transmission side circuit may include two or more stages of power amplifiers that amplify the high frequency transmission signal.

Thereby, even when a non-reciprocal circuit element in which the Rx pass characteristic has a superior balance to the Tx pass characteristic is used, it is possible to suppress the decrease in the level of the high-frequency transmission signal and maintain the communication quality.

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

According to such a communication device, communication quality can be improved by providing the nonreciprocal circuit element having a balance between the Tx pass characteristic and the Rx pass characteristic according to the required specifications.

According to the present invention, the Tx pass characteristic from the first port connected to the transmission side circuit to the third port connected to the antenna side circuit and the third port without changing the design inside the core unit, The balance with the Rx pass characteristic to the second port connected to the receiving side circuit can be easily adjusted.

FIG. 1 is an exploded perspective view showing a configuration of a circulator according to a basic form of an embodiment. FIG. 2 is a top view showing an arrangement layout of the adjustment circuit of the basic form. FIG. 3 is an equivalent circuit diagram of the circulator according to the basic form. FIG. 4A is a top view showing the configuration of the circulator of the first application example. FIG. 4B is an equivalent circuit diagram of the circulator of the first application example. FIG. 4C is a graph showing pass characteristics of the circulator of the first application example. FIG. 5A is a top view showing the configuration of the circulator of the second application example. FIG. 5B is an equivalent circuit diagram of the circulator of the second application example. FIG. 5C is a graph showing pass characteristics of the circulator of the second application example. FIG. 6A is a top view showing the configuration of the circulator of the third application example. FIG. 6B is an equivalent circuit diagram of the circulator of the third application example. FIG. 6C is a graph showing pass characteristics of the circulator of the third application example. FIG. 7A is a functional block diagram of an aspect of a communication device according to a modification of the embodiment. FIG. 7B is a functional block diagram of another aspect of the communication device according to the variation of the embodiment.

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

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

(Embodiment)
The nonreciprocal circuit element is an element that passes a high-frequency signal input to the first port to the third port and passes a high-frequency signal input to the third port to the second port. It is configured.

[Basic form]
First, the basic form of the circulator according to the present embodiment will be described.

FIG. 1 is an exploded perspective view showing a configuration of a circulator 1 according to a basic form of an embodiment.

The circulator 1 is mounted on, for example, a base station of a mobile phone, passes a transmission signal from the transmission side circuit to the antenna, and passes a reception signal received by the antenna to the reception side circuit. That is, the circulator 1 has a characteristic that allows a signal to pass only in a predetermined specific direction and does not substantially pass the signal in the reverse direction.

As shown in FIG. 1, the circulator 1 has a first port Port1, a second port Port2, and a third port Port3 as external connection terminals, and a high-frequency signal input from the first port Port1 is supplied to the third port Port3. The high-frequency signal input from the third port Port3 is passed to the second port Port2. In the present embodiment, the first port Port1 is a TX port (transmission terminal) connected to a transmission side circuit (not shown), and the second port Port2 is an RX port (not shown) connected to a reception side circuit (not shown). The third port Port3 is an ANT port (antenna terminal) connected to an antenna side circuit (not shown).

Specifically, the circulator 1 includes a lid 11, a case body 12, a core portion 40 constituted by the central conductor assembly 20 and the permanent magnet 30, an adjustment circuit constituted by a circuit board 51 and a chip component 52. 50.

The lid body 11 and the case body 12 are made of, for example, a magnetic member, and are integrally coupled in a state where the core portion 40 and the adjustment circuit 50 are accommodated, and function as an electromagnetic shield and a ground conductor. The case body 12 is integrally molded with a resin member 13, and is provided with a first port Port1, a second port Port2, and a third port Port3. The circulator 1 may not include the lid body 11, the case body 12, and the resin member 13. That is, the first port Port1, the second port Port2, and the third port Port3 may be, for example, front surface electrodes (lands) for connecting a motherboard provided on the back side of the circuit board 51.

The center conductor assembly 20 is mounted on a circuit board 51, and a ferrite 25 to which a DC magnetic field is applied by a permanent magnet 30, and a first center conductor 21 and a first center conductor 21 which are arranged to intersect with each other in an insulated state. It has two center conductors 22 and a third center conductor 23.

The ferrite 25 is a rectangular member having magnetism, and the first center conductor 21, the second center conductor 22, and the third center conductor 23 are wound, for example, by two turns. As the material of the ferrite 25, for example, ferrite containing iron oxide as a main component and containing at least one of zinc, nickel, and copper is used.

The first center conductor 21, the second center conductor 22, and the third center conductor 23 are so-called internal conductors (also referred to as center electrodes) of the circulator 1, and a thin film conductor, a thick film conductor, or It can be formed as a conductor foil. Specifically, each of the first center conductor 21, the second center conductor 22, and the third center conductor 23 is predetermined with an insulator layer (not shown) laminated on the upper and lower surfaces of the ferrite 25 interposed therebetween. It is arranged to intersect at an angle of. As a material of the first central conductor 21, the second central conductor 22, and the third central conductor 23, for example, a metal or alloy mainly containing silver is used.

The permanent magnet 30 is placed on the central conductor assembly 20 and applies a DC magnetic field to the central conductor assembly 20. The mounting position of the permanent magnet 30 is not limited to the center conductor assembly 20, and may be on the side of the center conductor assembly 20, for example.

The adjustment circuit 50 is disposed outside the core unit 40, and in the use frequency band of the circulator 1 (hereinafter simply referred to as “use frequency band”), the pass characteristic from the first port Port1 to the third port Port3 (ie, Tx) The balance between the pass characteristic) and the pass characteristic from the third port Port3 to the second port Port2 (that is, the Rx pass characteristic) is adjusted. Specifically, in the circulator 1, the Tx pass characteristic and the Rx pass characteristic are in a trade-off relationship. For example, when the Tx pass characteristic is improved, the Rx pass characteristic is lowered, and when the Tx pass characteristic is lowered, the Rx pass characteristic is improved. The adjustment circuit 50 is a circuit for adjusting the balance between the Tx pass characteristic and the Rx pass characteristic in such a trade-off relationship to a desired balance according to the required specifications.

Specifically, the adjustment circuit 50 determines the insertion loss in the used frequency band in the propagation path from the first port Port1 to the third port Port3 and the propagation path from the third port Port3 to the second port Port2. The balance between the Tx pass characteristic and the Rx pass characteristic is adjusted by adjusting relative to a certain Rx path. In other words, the adjustment circuit 50 relatively adjusts the insertion loss bandwidth (hereinafter referred to as the passband) in which the insertion loss is equal to or less than a predetermined value (for example, 0.8 dB or less) between the Tx path and the Rx path. . That is, the adjustment circuit 50 adjusts one pass characteristic to a balance superior to the other pass characteristic by making one pass band of the Tx pass characteristic and the Rx pass characteristic wider than the other pass band. .

Here, a specific layout of the adjustment circuit 50 will be described with reference to FIG.

FIG. 2 is a top view showing an arrangement layout of the adjustment circuit 50 in the basic form. In the figure, a layout of, for example, a motherboard on which the circulator 1 is mounted is also shown. The same applies to the following top views.

The circuit board 51 has an insulating substrate body and various conductors. These various conductors include pattern conductors (hatched portions in the drawing) provided along the main surface of the circuit board 51 and via conductors provided in a direction perpendicular to the main surface. The circuit configuration of the circulator 1 is realized by connecting the core portion 40 and the chip component 52 with these various conductors. The circuit configuration of the circulator 1 will be described later.

In the pattern conductor, the surface electrode 151 for mounting the capacitors C1 to C3, Cs1 to Cs3, Cg1, Cg2, and Cj provided as the chip component 52 and the wiring for realizing the circuit configuration of the circulator 1 are provided. The wiring conductor 152 to be configured and the surface electrodes Core-P1, Core-P2, and Core-P3 for mounting the core portion 40 (particularly, the central conductor assembly 20) are included.

For example, an epoxy resin is used as the material of the substrate body, and silver or copper is used as various conductors. The various conductors may be plated with gold, for example.

The circulator 1 configured as described above constitutes the following circuit.

FIG. 3 is an equivalent circuit diagram of the circulator 1 according to the basic form of the present embodiment. In the figure, the correspondence between the circuit configuration and the core unit 40 and the adjustment circuit 50 is also conceptually shown.

As shown in the figure, the circulator 1 includes, as a circuit configuration, inductors L1 to L3 provided in the core unit 40, capacitors C1 to C3, Cs1 to Cs3, Cg1, Cg2, and Cj provided in the adjustment circuit 50. Inductors Ls1 and Ls2 are included.

The inductors L1 to L3 are constituted by conductors provided on the ferrite 25. Specifically, the inductor L1 is constituted by the first central conductor 21, the inductor L2 is constituted by the second central conductor 22, and the inductor L3 is constituted by the third central conductor 23.

The inductor L1 (that is, the first central conductor 21) has one end L1a connected to the first port Port1, and the inductor L2 (that is, the second central conductor 22) has one end L2a connected to the second port Port2. The inductor L3 (that is, the third central conductor 23) has one end L3a connected to the third port Port3.

Capacitors C 1 to C 3, Cs 1 to Cs 3, Cg 1, Cg 2, and Cj are chip capacitors configured by the chip component 52. Note that each of the capacitors C1 to C3, Cs1 to Cs3, Cg1, Cg2, and Cj does not have to be constituted by the chip component 52. For example, the capacitors C1 to C3, Cs1 to Cs3, Cg1, Cg2, and Cj The parasitic capacitance of the pattern conductor may be used.

The capacitors C1 to C3 and the capacitors Cs1 to Cs3 are matching capacitors provided corresponding to the first port Port1 to the third port Port3. The capacitor C1 and the capacitor Cs1 correspond to the first port Port1, and the capacitors C2 and Cs3 The capacitor Cs2 corresponds to the second port Port2, and the capacitor C3 and the capacitor Cs3 correspond to the third port Port3. Capacitors C1 to C3 and capacitors Cs1 to Cs3 are provided in the same manner except for the corresponding ports (that is, connected central conductors). Therefore, capacitor C1 and capacitor Cs1 will be described below, and capacitors C2, C3 and capacitors Description of Cs2 and Cs3 is omitted.

The capacitor C1 is a first matching capacitor that connects between one end L1a of the inductor L1 (that is, the first central conductor 21) and the ground potential. In the present embodiment, one end of the capacitor C1 is connected to a connection node between the inductor L1 and the capacitor Cs1, and the other end is connected to a ground terminal (not shown) via the capacitor Cg1.

The capacitor Cs1 is a second matching capacitor connected in series between the first port Port1 and the inductor L1. In the present embodiment, the capacitor Cs1 has one end connected to the first port Port1 and the other end connected to the inductor L1 and the capacitor C1.

As described above, the capacitor C1 and the capacitor Cs1 respectively include a shunt connection type matching capacitor that connects the connection node between the first port Port1 and the inductor L1 and the ground potential, and the first port Port1 and the inductor L1. It is a series connection type matching capacitor connected in series.

The capacitor Cg1 is a shunt-connected first element provided between the other end L1b of the inductor L1 (that is, the first central conductor 21) and the ground potential. That is, the adjustment circuit 50 includes the first capacitor (capacitor Cg1) as the first element. In the present embodiment, capacitor Cg1 has one end connected to inductor L1 and capacitor C1, and the other end connected to a ground terminal (not shown).

The capacitor Cg2 is a shunt-connected second element provided between the other end L2b of the inductor L2 (that is, the second central conductor 22) and the ground potential. That is, the adjustment circuit 50 includes the second capacitor (capacitor Cg2) as the second element. In the present embodiment, capacitor Cg2 has one end connected to inductor L2 and capacitor C2, and the other end connected to a ground terminal (not shown).

These capacitors Cg1 and Cg2 are elements for adjusting the balance between the Tx pass characteristic and the Rx pass characteristic to a desired balance. For this reason, the constants of the capacitors Cg1 and Cg2 are appropriately set in the range of 0.0 pF to 5.0 pF, for example, according to the specifications required for the circulator 1. For this reason, in order to develop the circulator 1 in various specifications while sharing the core portion 40 and the circuit board 51, it is preferable that the capacitors Cg1 and Cg2 are formed of chip components 52. That is, as shown in FIG. 2, the circuit board 51 is provided with

surface electrodes

151a and 151b for mounting chip components that constitute each of the capacitor Cg1 (first element) and the capacitor Cg2 (second element). It is preferable.

The capacitor Cj is connected between the first port Port1 and the second port Port2, one end is connected to the first port Port1, and the other end is connected to the second port Port2. By providing such a capacitor Cj, insertion loss from the first port Port1 to the third port Port3 can be reduced. For this reason, the circulator 1 having the capacitor Cj is suitable for, for example, a front end circuit (high frequency front end circuit) that requires a reduction in insertion loss from the transmission side circuit to the antenna. The circulator 1 may not have the capacitor Cj.

In the present embodiment, the inductors Ls1 and Ls2 are provided on the circuit board 51 and connect the other ends L1b to L3b of the inductors L1 to L3 (that is, the other ends of the first central conductors 21 to 23). Consists of conductors. That is, the inductors Ls1 and Ls2 are parasitic inductances due to the wiring conductor 152 and the via conductor (not shown) provided on the circuit board 51. Note that at least one of the inductance components of at least one of the inductors Ls1 and Ls2 may be configured by a chip component.

The inductor Ls1 is a first inductor that connects the other end L1b of the inductor L1 (ie, the first central conductor 21) and the other end L3b of the inductor L3 (ie, the third central conductor 23). Specifically, the inductor Ls1 has one end connected to the inductor L1 and the other end connected to the inductors L3 and Ls2.

The inductor Ls2 is a second inductor that connects the other end L3b of the inductor L3 (ie, the third central conductor 23) and the other end L2b of the inductor L2 (ie, the second central conductor 22). Specifically, one end of the inductor Ls2 is connected to the inductors L3 and Ls1, and the other end is connected to the inductor L2.

In the circulator 1 configured as described above, a high-frequency signal (for example, a transmission signal) input to the first port Port1 propagates from the first center conductor 21 to the third center conductor 23 by magnetic coupling, and the third port Output from Port3. A high-frequency signal (for example, a received signal) input to the third port Port3 propagates from the third center conductor 23 to the second center conductor 22 by magnetic coupling and is output from the second port Port2.

At this time, the adjustment circuit 50 can set the balance between the Tx pass characteristic and the Rx pass characteristic to any one of the following three states by appropriately setting the constants of the capacitors Cg1 and Cg2. . Specifically, the adjustment circuit 50 (i) has a balanced balance between the Tx pass characteristic and the Rx pass characteristic according to the constants of the capacitors Cg1 and Cg2, and (ii) the Tx pass characteristic is superior to the Rx pass characteristic. Any one of the three states of balance and (iii) a balance in which the Rx pass characteristic is superior to the Tx pass characteristic can be set. Note that “equivalent” not only means that they are completely matched, but also means that they are substantially matched. That is, “equivalent” includes an error of about several percent.

Therefore, hereinafter, as an application example of the circulator 1, a configuration for realizing each of the three balances (i) to (iii) will be described.

[First application example]
First, as a first application example, a description will be given of a circulator 1A in which (i) the Tx pass characteristic and the Rx pass characteristic are in the same balance.

FIG. 4A is a top view showing the configuration of the circulator 1A of the first application example. FIG. 4B is an equivalent circuit diagram of the circulator 1A of the first application example.

The circulator 1A shown in these drawings has the same configuration as the circulator 1 according to the basic form described above. Specifically, in this application example, the adjustment circuit 50 includes both a capacitor Cg1 (first capacitor) and a capacitor Cg2 (second capacitor), and the capacitors Cg1 and Cg2 have substantially the same capacitance value. Have. Note that “substantially the same” not only means that they are completely matched, but also means that they are included in a range of a numerical value width of, for example, 10% or less.

FIG. 4C is a graph showing pass characteristics of the circulator 1A of the first application example.

Specifically, the figure shows the Tx pass characteristic (S31_TX to ANT in the figure) and the Rx pass characteristic (S23_ANT to RX in the figure), where the horizontal axis is frequency and the vertical axis is input. The intensity ratio (insertion loss) of the output high frequency signal to the intensity of the high frequency signal is shown. In the graph, the range of the used frequency band of the circulator 1A is indicated by

markers

1 and 2. Also, on the graph, the capacitance values of the capacitors Cg1 and Cg2 (here, both are 2.5 pF) when this pass characteristic is obtained are shown. The same applies to the graphs of the pass characteristics.

As shown in FIG. 4C, according to the circulator 1A of the first application example, the Tx pass characteristic and the Rx pass characteristic can be equally balanced in the used frequency band.

[Second application example]
Next, as a second application example, a description will be given of (ii) the circulator 1B in which the above-described Tx pass characteristic has a balance superior to the Rx pass characteristic.

FIG. 5A is a top view showing the configuration of the circulator 1B of the second application example. FIG. 5B is an equivalent circuit diagram of the circulator 1B of the second application example.

The circulator 1B shown in these drawings is different from the circulator 1 according to the basic embodiment described above in that the capacitor Cg2 is not provided. That is, in this application example, the adjustment circuit 50 includes only the capacitor Cg1 among the capacitor Cg1 (first capacitor) and the capacitor Cg2 (second capacitor). Specifically, since the capacitor Cg2 is not provided, as shown in FIG. 5A, the surface electrode 151b becomes an electrode in which a chip component is not mounted.

FIG. 5C is a graph showing pass characteristics of the circulator 1B of the second application example. The capacitance value of the capacitor Cg1 when this pass characteristic is obtained is 5.0 pF.

As shown in the figure, according to the circulator 1B of the second application example, it is possible to balance the Tx pass characteristic over the Rx pass characteristic in the used frequency band.

[Third application example]
Next, as a third application example, a description will be given of (iii) the circulator 1C in which the above-described (iii) Rx pass characteristic has a balance superior to the Tx pass characteristic.

FIG. 6A is a top view showing the configuration of the circulator 1C of the third application example. FIG. 6B is an equivalent circuit diagram of the circulator 1C of the third application example.

The circulator 1C shown in these drawings is different from the circulator 1 according to the basic form described above in that the capacitor Cg1 is not provided. That is, in this application example, the adjustment circuit 50 includes only the capacitor Cg2 among the capacitor Cg1 (first capacitor) and the capacitor Cg2 (second capacitor). Specifically, since the capacitor Cg1 is not provided, as shown in FIG. 6A, the surface electrode 151a becomes an electrode in which a chip component is not mounted.

FIG. 6C is a graph showing pass characteristics of the circulator 1C of the third application example. The capacitance value of the capacitor Cg2 when this pass characteristic is obtained is 5.0 pF.

As shown in the figure, according to the circulator 1C of the third application example, it is possible to balance the Rx pass characteristic over the Tx pass characteristic in the used frequency band.

[Summary]
As shown in the first to third application examples described above, according to the circulator according to the present embodiment, the adjustment circuit 50 causes the Tx pass characteristic from the first port Port1 to the third port Port3 and The superiority with the Rx passage characteristic to the second port Port2 can be adjusted. Specifically, according to the present embodiment, the adjustment circuit 50 that adjusts the balance between the Tx pass characteristic and the Rx pass characteristic is provided outside the core part 40, thereby changing the design inside the core part 40. Even without this, the balance between the Tx pass characteristic and the Rx pass characteristic can be easily changed.

Specifically, according to the present embodiment, the adjustment circuit 50 connects the other end of the first central conductor 21 (end L1b of the inductor L1) and the ground potential (in this embodiment, At least one of the capacitor Cg1) and the second element (capacitor Cg2 in this embodiment) that connects the other end of the second central conductor (end L2b of the inductor L2) and the ground potential. Thus, the balance between the Tx pass characteristic and the Rx pass characteristic can be easily changed without changing the design inside the core unit 40.

In addition, according to the present embodiment, the adjustment circuit 50 includes the first capacitor (capacitor Cg1) as the first element, so that the first central conductor 21 and the first capacitor are shunt-connected LC series resonance circuits. Form. Therefore, by providing the first capacitor that causes the LC series resonance circuit to resonate in the vicinity of the used frequency band, the first central conductor 21 behaves as follows. That is, when a high frequency signal is input from the first port Port 1, the first center conductor 21 is not only resonated by magnetic coupling with the second center conductor 22 but also by an LC series resonance circuit formed by the first capacitor. Also resonates. That is, the first center conductor 21 can be made to resonate by providing the first capacitor. At this time, if the first inductor (inductor Ls1) is provided, a potential difference is generated between the other end of the first center conductor 21 and the other end of the third center conductor 23. The Tx pass characteristic can be broadened by the double resonance of the conductor 21.

In other words, by providing the first capacitor, the path to the ground potential on the first center conductor 21 side is shortened, and unnecessary inductance components can be reduced. For this reason, the Tx pass characteristic can be widened.

Note that the second capacitor (capacitor Cg2) and the second inductor (inductor Ls2) can also have a wide band of Rx pass characteristics by the same mechanism as the first capacitor and the first inductor.

For example, according to the circulator 1A of the first application example, the adjustment circuit 50 includes both the first capacitor and the second capacitor, and the first capacitor and the second capacitor have substantially the same capacitance value. Thereby, the circulator 1A of the first application example can balance the Tx pass characteristic and the Rx pass characteristic in the use frequency band.

Further, for example, according to the circulator 1B of the second application example, the adjustment circuit 50 includes only the first capacitor among the first capacitor and the second capacitor. Thereby, the circulator 1B of the second application example can balance the Tx pass characteristic over the Rx pass characteristic in the used frequency band.

For example, according to the circulator 1C of the third application example, the adjustment circuit 50 includes only the second capacitor among the first capacitor and the second capacitor. As a result, the circulator 1C of the third application example can balance the Rx pass characteristic over the Tx pass characteristic in the used frequency band.

Further, according to the present embodiment, the adjustment circuit 50 includes both the first inductor (inductor Ls1) and the second inductor (inductor Ls2), so that only the constants of the first capacitor and the second capacitor are changed. The balance between the Tx pass characteristic and the Rx pass characteristic can be easily changed.

Further, according to the present embodiment, at least one of the first inductor and the second inductor (both in the present embodiment) is a conductor provided on the circuit board 51 (that is, the wiring conductor 152 and the via conductor (not shown). )), The number of parts can be reduced.

Further, according to the present embodiment, the adjustment circuit 50 includes the first matching capacitors (capacitors C1 to C3), so that the adjustment circuit 50 can pass in the use frequency band by appropriately selecting the capacitance value of the first matching capacitors. The characteristics can be broadened. Further, since the adjustment circuit 50 includes the second matching capacitors (capacitors Cs1 to Cs3), the impedance of the first to third ports Port1 to Port3 can be easily selected by appropriately selecting the capacitance value of the second matching capacitors. Can be adjusted. For this reason, loss can be improved (deterioration of insertion loss is reduced).

Further, according to the present embodiment, the circuit board 51 is provided with the chip components 52 constituting each of the first element (capacitor Cg1 in the present embodiment) and the second element (capacitor Cg2 in the present embodiment).

Surface electrodes

151a and 151b for mounting are provided. Thereby, by using the common core part 40 and the circuit board 51, the first element and the second element are appropriately mounted according to the required specifications, so that the non-reciprocal characteristics have a balance of pass characteristics according to the specifications. A circuit element (a circulator in this embodiment) can be realized. That is, the range of development (reuse) of the core part 40 is widened, and the cost can be reduced.

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

7A and 7B are functional block diagrams of a communication apparatus according to a modification including the circulator described in the embodiment. Specifically, FIG. 7A is a functional block diagram of a communication device 2A including the circulator 1A of the first application example of the embodiment. FIG. 7B is a functional block diagram of a communication device 2C including the circulator 1C of the third application example of the embodiment.

First, the communication device 2A shown in FIG. 7A will be described.

As shown in FIG. 7A, the communication device 2A is, for example, a mobile phone base station including a front end circuit 100A having a circulator 1A, an RFIC (Radio Frequency Integrated Circuit) 200, and an antenna element 300. The communication device 2A may not include the antenna element 300.

The front end circuit 100A is provided at the front end of the communication device 2A and propagates a transmission signal or a reception signal between the RFIC 200 and the antenna element 300. Specifically, in addition to the circulator 1A, the front end circuit 100A further includes a transmission side circuit such as a PA (Power Amplifier) 202, a BPF (Band Pass Filter) 203, and an LNA (Low Noise Amplifier). 204 and other receiving side circuits. Further, the front end circuit 100A is provided with a transmission terminal Ptx to which a transmission signal is input, an antenna terminal Pant to which the transmission signal is output and a reception signal is input, and a reception terminal Prx that outputs the reception signal. . The front end circuit 100A may not include the BPF 203, and may include a matching circuit other than the above, a transmission or reception filter, or the like.

In the circulator 1A, the first port Port1 is connected to the transmission side circuit (here, PA202), the second port Port2 is connected to the reception side circuit (here, LNA204), and the third port Port3 is connected to the antenna terminal Pant. Yes. Specifically, the first port Port 1 is connected to the transmission terminal Ptx via the PA 202, the second port Port 2 is connected to the reception terminal Prx via the LNA 204, and the third port Port 3 is connected to the antenna terminal Pant via the BPF 203. It is connected.

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

The BPF 203 passes the transmission signal output from the circulator 1A after filtering it in a predetermined use frequency band. Further, the BPF 203 passes the received signal input from the antenna terminal Pant after filtering in the use frequency band.

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

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

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

The antenna element 300 is connected to the antenna terminal Pant of the front end circuit 100A, transmits a transmission signal, and receives a reception signal. The shape and the like of the antenna element 300 are not particularly limited, and may be appropriately designed according to the use frequency band of the communication device 2A.

In the communication apparatus 2A configured as described above, in order to improve communication quality, for example, with respect to the circulator, for example, the transmission path path characteristics (that is, Tx path characteristics) and the reception path paths (that is, Rx). It is required to have an equivalent balance with the transmission characteristics. Therefore, the communication device 2A can improve communication quality by using the circulator 1A of the first application example described above as the circulator.

Next, the communication device 2C shown in FIG. 7B will be described.

As shown in FIG. 7B, the communication device 2C includes a front-end circuit 100C instead of the front-end circuit 100A as compared with the communication device 2A. The front end circuit 100C includes a circulator 1C and a plurality of stages of PAs (here, two stages of PAs 202a and 202b) instead of the circulators 1A and PA 202, as compared with the front end circuit 100A. 206.

The

PAs

202a and 202b are provided with a plurality of stages (here, two stages), thereby amplifying the transmission signal with a larger amplification factor than the PA 202. The number of PA stages is not limited to two, and may be three or more.

The switch 205 is a switch circuit that selectively connects the second port Port2 of the circulator 1C and the reception side circuit (here, the LNA 204). Specifically, the switch 205 has a common terminal connected to the circulator 1 </ b> C and two selection terminals connected to the LNA 204 or the termination resistor 206. For example, according to a control signal from the RFIC 200, the switch 205 connects a common terminal to a selection terminal connected to the termination resistor 206 at the time of transmission and to a selection terminal connected to the LNA 204 at the time of reception. The switch 205 is not limited to the 1-input 2-output type.

The terminating resistor 206 is a shunt-connected resistor having one end connected to the selection terminal of the switch 205 and the other end connected to the ground potential, for example, having a resistance value of 50Ω.

In the front-end circuit 100C configured as described above, the switch 205 is provided as compared with the front-end circuit 100A, so that the transmission signal to the reception-side circuit (here, the LNA 204) can be suppressed. . Therefore, communication quality can be improved.

However, in the front end circuit 100C, by providing the switch 205, the passing characteristic from the antenna terminal Pant to the receiving terminal Prx may be slightly deteriorated. Therefore, the level of the reception signal output from the reception terminal Prx may be reduced.

Therefore, in such a communication device 2C, in order to improve communication quality, for example, it is required for the circulator to balance the Rx pass characteristic over the Tx pass characteristic. Therefore, the communication device 2C can improve the communication quality by suppressing the decrease in the level of the reception signal output from the reception terminal Prx by using the circulator 1C of the third application example described above as the circulator. That is, it is possible to suppress the deterioration of the passing characteristics from the antenna terminal Pant to the reception terminal Prx of the front end circuit 100C.

Further, in the front end circuit 100C, in the circulator 1C, the level of the transmission signal output from the antenna terminal Pant is obtained because the pass characteristic of the reception system path is more balanced than the transmission characteristic of the transmission system path. Can be reduced. Therefore, by providing a plurality of PAs (in this case, two stages) to increase the amplification factor, it is possible to suppress the decrease in the level of the transmission signal and maintain the communication quality.

According to the

communication devices

2A and 2C described above, communication quality can be improved by providing the

circulators

1A and 1C having a balance of pass characteristics according to required specifications.

In communication device 2A, circulator 1B may be provided instead of circulator 1A. According to such a configuration, the level of the transmission signal output from the antenna terminal Pant can be increased, which is particularly suitable for a mobile phone base station or the like.

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

For example, the adjustment circuit 50 includes both a first capacitor (capacitor Cg1) and a second capacitor (capacitor Cg2), and the first capacitor may have a larger capacitance value than the second capacitor.

The circulator having such an adjustment circuit 50 has a lower balance adjustment range than the circulator 1B of the second application example. However, like the circulator 1B, the circulator has a Tx pass characteristic higher than the Rx pass characteristic in the operating frequency band. An excellent balance can be achieved. Specifically, the circulator having such an adjustment circuit 50 has a Tx pass characteristic which is better than that of the first application example and deteriorated from the second application example, and an Rx pass characteristic which deteriorates from that of the first application example. It is better than the application example.

For example, the adjustment circuit 50 includes both the first capacitor (capacitor Cg1) and the second capacitor (capacitor Cg2), and the second capacitor may have a larger capacitance value than the first capacitor.

Although the circulator having such an adjustment circuit 50 is inferior in the balance adjustment range as compared with the circulator 1C of the third application example, as in the circulator 1C, the Rx pass characteristic is higher than the Tx pass characteristic in the used frequency band. An excellent balance can be achieved. Specifically, the circulator having such an adjustment circuit 50 has a Tx pass characteristic that is worse than that of the first application example and is better than that of the third application example, and an Rx pass characteristic that is better than that of the first application example and third. Deteriorated from application examples.

In the above description, the capacitor Cg1 is described as an example of the shunt connection type first element that connects the other end portion (end portion L1b) of the first central conductor 21 and the ground potential. Further, the capacitor Cg2 has been described as an example of the second element of the shunt connection type that connects the other end portion (end portion L2b) of the second central conductor 22 and the ground potential. However, at least one of the first element and the second element may not be a capacitor.

In the above description, the adjustment circuit 50 has both the first inductor (inductor Ls1) and the second inductor (inductor Ls2). For example, the adjustment circuit 50 may not have the second inductor when the capacitor Cg1 is included. Even in such a configuration, when the first center conductor 21 undergoes double resonance, the other end portion (end portion L1b) of the first center conductor 21 and the other end portion (end portion L3b) of the third center conductor 23 are arranged. ), The Tx pass characteristic can be widened. Similarly, the adjustment circuit 50 does not have to include the first inductor when the capacitor Cg2 is provided. Even in such a configuration, the adjustment circuit 50 has the same mechanism as that of the configuration without the capacitor Cg1 and the second inductor. , Rx pass characteristics can be widened.

In the above description, the adjustment circuit 50 has the first matching capacitors (capacitors C1 to C3) and the second matching capacitors (capacitors Cs1 to Cs3). However, the adjustment circuit 50 does not have at least a part of these. It doesn't matter. In the above description, the capacitor C1 is connected to the ground potential via the capacitor Cg1, and the capacitor C2 is connected to the ground potential via the capacitor Cg2. However, the capacitors C1 and C2 are directly connected to the ground potential. It does not matter.

Further, in the nonreciprocal circuit element, the front end circuit, and the communication device according to the above-described embodiment, another circuit element and wiring are inserted between the circuit elements disclosed in the drawings and the path connecting the signal paths. It does not matter.

In the above description, a three-port nonreciprocal circuit element (circulator) is described as an example of the nonreciprocal circuit element. However, the nonreciprocal circuit element may have a plurality of ports of four or more ports.

The ground potential may be a circuit ground potential (reference potential) of the non-reciprocal circuit element, and may be 0 V, a ground ground potential (that is, a ground reference potential), or a potential different from the frame ground.

The present invention can be widely used in communication devices such as mobile phone base stations as a circulator disposed in the front end of the communication device.

DESCRIPTION OF

SYMBOLS

1, 1A, 1B,

1C Circulator

2A, 2C Communication apparatus 11 Cover body 12 Case main body 13 Resin member 20 Central conductor assembly 21 1st center conductor 22 2nd center conductor 23 3rd center conductor 25 Ferrite 30 Permanent magnet 40 Core part 50 adjustment circuit 51 circuit board 52

chip component

100A, 100C

front end circuit

151, 151a, 151b surface electrode 152 wiring conductor 200 RFIC
202, 202a, 202b PA
203 BPF
204 LNA
205 Switch 206 Termination resistor 300 Antenna element C1 to C3, Cs1 to Cs3, Cg1, Cg2 Capacitor L1 to L3, Ls1, Ls2 Inductor L1a to L3a, L1b to L3b End (end of inductor)
Pant antenna terminal Port1 1st port Port2 2nd port Port3 3rd port Prx receiving terminal Ptx transmitting terminal

Claims

The high-frequency signal input to the first port connected to the transmission-side circuit is passed to the third port connected to the antenna-side circuit, and the high-frequency signal input to the third port is connected to the reception-side circuit. A nonreciprocal circuit element that passes through the second port,
A permanent magnet, a ferrite to which a DC magnetic field is applied by the permanent magnet, and a first central conductor, each of which is arranged to intersect with each other in an insulated state, one end of which is connected to the first port; A core portion having a second central conductor having one end connected to the second port and a third central conductor having one end connected to the third port;
A balance between the pass characteristic from the first port to the third port and the pass characteristic from the third port to the second port in the frequency band of the nonreciprocal circuit element that is disposed outside the core unit. An adjustment circuit for adjusting
Non-reciprocal circuit element.
The adjustment circuit includes a shunt connection type first element that connects the other end of the first center conductor and a ground potential, and a shunt that connects the other end of the second center conductor and a ground potential. Having at least one of the connection-type second elements,
The nonreciprocal circuit device according to claim 1.
The first element has a first capacitor; the second element has a second capacitor;
A first inductor connecting the other end of the first central conductor and the other end of the third central conductor; and the other end of the third central conductor and the second central conductor. Having at least one of the second inductors connected to the other end,
The nonreciprocal circuit device according to claim 2.
The adjustment circuit includes only the first capacitor of the first capacitor and the second capacitor.
The nonreciprocal circuit device according to claim 3.
The adjustment circuit includes only the second capacitor among the first capacitor and the second capacitor.
The nonreciprocal circuit device according to claim 3.
The adjustment circuit includes both the first capacitor and the second capacitor;
The first capacitor has a larger capacitance value than the second capacitor,
The nonreciprocal circuit device according to claim 3.
The adjustment circuit includes both the first capacitor and the second capacitor;
The second capacitor has a larger capacitance value than the first capacitor,
The nonreciprocal circuit device according to claim 3.
The adjustment circuit includes both the first capacitor and the second capacitor;
The first capacitor and the second capacitor have substantially the same capacitance value.
The nonreciprocal circuit device according to claim 3.
The adjustment circuit includes both the first inductor and the second inductor.
The nonreciprocal circuit device according to any one of claims 3 to 8.
The nonreciprocal circuit element includes a circuit board on which the core unit is mounted and the adjustment circuit is provided,
At least one of the first inductor and the second inductor is provided on the circuit board, and connects the other ends of the first central conductor, the second central conductor, and the third central conductor to each other. Composed of conductors,
The nonreciprocal circuit device according to any one of claims 3 to 9.
The adjustment circuit further includes:
A first matching capacitor that connects one end of each of the first central conductor, the second central conductor, and the third central conductor to a ground potential;
Connected in series between the first port and the first central conductor, between the second port and the second central conductor, and between the third port and the third central conductor, respectively. A second matching capacitor;
The nonreciprocal circuit device according to any one of claims 2 to 10.
The nonreciprocal circuit element includes a circuit board on which the core unit is mounted and the adjustment circuit is provided,
The circuit board is provided with surface electrodes for mounting chip components constituting each of the first element and the second element.
The nonreciprocal circuit device according to any one of claims 2 to 11.
A nonreciprocal circuit device according to any one of claims 1 to 11,
A transmitting circuit connected to the first port;
A receiving circuit connected to the second port;
An antenna terminal connected to the third port,
Front-end circuit.
And a switch circuit that selectively connects the second port and the receiving circuit.
The front end circuit according to claim 13.
The transmission circuit includes two or more power amplifiers for amplifying a high-frequency transmission signal.
The front end circuit according to claim 13 or 14.
A signal processing circuit for processing high-frequency signals;
A front end circuit according to any one of claims 13 to 15.
Communication device.