WO2015156056A1

WO2015156056A1 - Non-reciprocal circuit element and high-frequency module

Info

Publication number: WO2015156056A1
Application number: PCT/JP2015/055951
Authority: WO
Inventors: 裕亮楠本; 和田　貴也; 礼滋中嶋
Original assignee: 株式会社村田製作所
Priority date: 2014-04-09
Filing date: 2015-02-27
Publication date: 2015-10-15

Abstract

A non-reciprocal circuit element wherein high-value isolation properties are obtained across a wide range. The non-reciprocal circuit element comprises: ferrite (10); first, second, third, and fourth center electrodes (L1 L2, L3, L4) that are arranged wound at least one turn on to the ferrite (10), each in an insulated state, and having one end of each connected to a ground; first matching capacitor elements (C1, C2, C3) that are connected to the other end of the first, second, and third center electrodes (L1, L2, L3), respectively, and are connected to a ground; and second matching capacitor elements (CS1, CS2, CS3) that are connected between the other end of the first center electrode (L1) and a first I/O port (P1), the other end of the second center electrode (L2) and a second I/O port (P2), and the other end of the third center electrode (L3) and a third I/O port (P3), respectively.

Description

Non-reciprocal circuit device and high-frequency module

The present invention relates to a nonreciprocal circuit device, and more particularly to a nonreciprocal circuit device such as a circulator used in a microwave band and a high-frequency module including the nonreciprocal circuit device.

Conventionally, as circulators (non-reciprocal circuit elements) employed in mobile communication devices such as mobile phones, those described in

Patent Documents

1 and 2 are known. Specifically, as shown in FIG. 16, three center electrodes L1, L2, and L3 are wound around a ferrite 10 to which a DC magnetic field X is applied in an insulated state, and one end of each of the center electrodes L1, L2, and L3 is wound. Is connected to the ground (a series resonant circuit composed of an inductance element L11 and a capacitor element C11 may be inserted), and matching capacitors C1, C2, and C3 are connected in parallel to the other end, respectively. A device in which the other end is configured as an input / output port P1 (TX), P2 (ANT), or P3 (RX) is known.

This type of circulator is a three-port lumped constant type circulator, and the center electrodes L1, L2, L3 are arranged on one surface of the ferrite 10 so as to cross each other in an electrically insulated state. The operating frequency is adjusted by the capacitance values of the capacitors C1, C2, and C3 arranged in parallel with the center electrodes L1, L2, and L3.

In the circulator described above, the high frequency signal input from the port P1 (TX) is transmitted to the port P2 (ANT), and the high frequency signal input from the port P2 (ANT) is transmitted to the port P3 (RX). The isolation characteristics between the ports P1 and P3 depend on the tensor permeability of the ferrite 10 and the port impedances of the ports P1 and P3. The isolation characteristic between the ports P1 and P3 also depends on the magnetic coupling A between the center electrodes L1 and L3. Since the center electrodes L1 and L3 are arranged adjacent to each other on the ferrite 10, it is difficult to obtain a large value of isolation characteristics in a wide frequency band. Further, the impedance of the antenna may vary depending on the environment around the antenna, and if such a variation in impedance occurs, the isolation characteristic from the transmission port TX to the reception port RX is greatly deteriorated. Has occurred.

JP 2002-100905 A International Publication No. 2011/118278

An object of the present invention is to provide a non-reciprocal circuit element and a high-frequency module that can obtain a large value of isolation characteristics in a wide band. Another object of the present invention is to provide a non-reciprocal circuit element and a high-frequency module in which isolation characteristics hardly deteriorate even when the impedance of the antenna fluctuates.

The nonreciprocal circuit device according to the first aspect of the present invention is
With ferrite,
First, second, third, and fourth center electrodes, each of which is arranged to be wound around the ferrite in at least one turn in an insulated state, and each one end of which is connected to the ground,
A first matching capacitor element connected to each of the other ends of the first, second and third center electrodes and connected to the ground;
Between the other end of the first center electrode and the first input / output port, between the other end of the second center electrode and the second input / output port, and between the other end of the third center electrode and the third input A second matching capacitor element connected to the output port;
It is provided with.

The high-frequency module according to the second aspect of the present invention is
The non-reciprocal circuit device according to the first form is provided,
The first input / output port is a transmission port, the second input / output port is an antenna port, and the third input / output port is a reception port;
It is characterized by.

In the non-reciprocal circuit device according to the first aspect, the first, second, and third center electrodes are each wound at least one turn around the ferrite, so that the impedance is increased, and the insertion loss and the isolation characteristics are reduced. Broadband. In particular, by providing the fourth center electrode, the isolation characteristic between the other end portions (ports) between two other center electrodes facing each other across the fourth center electrode is improved over a wide band.

The non-reciprocal circuit device according to the third aspect of the present invention is
With ferrite,
First, second, third, and fourth center electrodes, each of which is arranged to be wound around the ferrite in at least one turn in an insulated state, and each one end of which is connected to the ground,
A first matching capacitor element connected to the other end of each of the first, second, third and fourth center electrodes and connected to the ground;
Between the other end of the first center electrode and the first input / output port, between the other end of the second center electrode and the second input / output port, and the other end of the third center electrode and the third input / output port And a second matching capacitor element connected between the other end of the fourth center electrode and the fourth input / output port,
It is provided with.

The high-frequency module according to the fourth aspect of the present invention is
A non-reciprocal circuit device according to the third embodiment;
The first input / output port is a transmission port, the second input / output port is a first antenna port, the third input / output port is a second antenna port, and the fourth input / output port is a reception port. ,
It is characterized by.

In the non-reciprocal circuit device according to the third aspect, the first, second, third, and fourth center electrodes are each wound at least one turn around the ferrite, so that the impedance is increased, and the insertion loss and the isolator are isolated. Broadband characteristics. In particular, if the second input / output port is the first antenna port and the third input / output port is the second antenna port, even if the impedance of the first or second antenna fluctuates, the signal is received from the transmission port. There is almost no deterioration in the isolation characteristics of the port.

The nonreciprocal circuit device according to the fifth aspect of the present invention is
With ferrite,
First, second, third, and fourth center electrodes, each of which is arranged to be wound around the ferrite in at least one turn in an insulated state, and each one end of which is connected to the ground,
A first matching capacitor element connected to the other end of each of the first, second and fourth center electrodes and connected to the ground;
Between the other end of the first center electrode and the first input / output port, between the other end of the second center electrode and the second input / output port, and between the other end of the fourth center electrode and the fourth input A second matching capacitor element connected to the output port;
A resistance element connected to the other end of the third center electrode and connected to the ground;
A filter having a fixed or variable pass characteristic connected between the other end of the third center electrode and the resistance element;
It is provided with.

The high-frequency module according to the sixth aspect of the present invention is
A nonreciprocal circuit device according to the fifth embodiment;
The first input / output port is a transmission port, the second input / output port is an antenna port, and the fourth input / output port is a reception port;
It is characterized by.

In the non-reciprocal circuit device according to the fifth aspect, the first, second, third, and fourth center electrodes are wound around the ferrite for at least one turn, so that the impedance is increased, and the insertion loss and the isolator are isolated. Broadband characteristics. In particular, if the first input / output port is a transmission port, the second input / output port is an antenna port, and the fourth input / output port is a reception port, even if the impedance of the antenna fluctuates, The isolation characteristic from the port to the receiving port hardly deteriorates.

According to the present invention, it is possible to obtain a large isolation characteristic in a wide band, and it is possible to prevent deterioration of the isolation characteristic even if the impedance of the antenna fluctuates.

It is an equivalent circuit diagram of the nonreciprocal circuit device according to the first embodiment. It is a perspective view which shows schematic structure of the center electrode which comprises 1st Example. 3 is a graph showing isolation characteristics between ports P1 and P3 in the first embodiment. 4 is a graph showing insertion loss characteristics between ports P1 and P2 and isolation characteristics between ports P2 and P1, with (A) showing the characteristics in the first embodiment and (B) showing the characteristics in the comparative example. . It is a block diagram which shows the high frequency module using the nonreciprocal circuit element which is 1st Example. It is the equivalent circuit of the nonreciprocal circuit device which is 2nd Example. It is a graph which shows the characteristic of the nonreciprocal circuit element which is 2nd Example, (A) shows an impedance characteristic, (B) shows the isolation characteristic according to the fluctuation | variation of an impedance, (C) is for reference Shows the isolation characteristics according to the impedance variation in the conventional example. It is a perspective view which shows the 1st example of a mobile telephone. It is a top view which shows the 2nd example of a mobile telephone. It is the equivalent circuit schematic of the nonreciprocal circuit device which is 3rd Example. It is the equivalent circuit schematic of the nonreciprocal circuit device which is 4th Example. It is a block diagram which shows the high frequency module using the nonreciprocal circuit device which is 4th Example. It is a graph which shows the characteristic (isolation characteristic according to the fluctuation | variation of the impedance of an antenna) of the nonreciprocal circuit element which is 4th Example. It is a graph which shows the characteristic (isolation characteristic by the reflective phase of an antenna) of the nonreciprocal circuit element which is 4th Example, (A) shows this invention example, (B) shows the prior art example for reference. . It is a block diagram which shows the other example of a high frequency module. It is an equivalent circuit diagram of the nonreciprocal circuit device which is a conventional example.

Hereinafter, embodiments of the non-reciprocal circuit device and the high-frequency module according to the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same member, and the overlapping description is abbreviate | omitted.

(First embodiment, FIGS. 1 to 4)
The nonreciprocal circuit device 1A according to the first embodiment is configured as a 4-port type lumped constant circulator as shown in the equivalent circuit of FIG. 1st, 2nd, 3rd, 4th center electrode L1, L2, L3, L4 which is arrange | positioned and wound at least 1 turn in the insulated state, and each one end part was connected to the ground GND is provided. . A resistance element R connected to the ground (fourth input / output port P4) is connected to the other end of the fourth center electrode L4.

The first matching capacitor elements C1, C2, and C3 connected to the ground are connected to the other ends of the first, second, and third center electrodes L1, L2, and L3, respectively. Further, between the other end of the first center electrode L1 and the first input / output port P1 (transmission port TX), the other end of the second center electrode L2 and the second input / output port P2 (antenna port ANT). And second matching capacitor elements CS1, CS2 and CS3 are connected between the other end of the third center electrode L3 and the third input / output port P3 (receiving port RX), respectively. Yes.

One end portions of the first, second, third, and fourth center electrodes L1, L2, L3, and L4 are connected to the ground GND through a series resonance circuit including an inductance element L11 and a capacitor element C11. . This series resonant circuit is not always necessary.

The center electrodes L1, L2, L3, and L4 are formed of a conductor pattern wound around the upper and lower surfaces of the rectangular ferrite 10, as shown in FIG. Specifically, the first center electrode L1 includes

conductor patterns

31 and 33 provided on the top surface of the ferrite 10, a conductor pattern 32 provided on the bottom surface, and interlayer conductors 34a and 34b provided on the side surfaces. One end is connected to the port P1, the other end of the conductor pattern 31 is connected to one end of the conductor pattern 32 via the interlayer conductor 34a, and the other end of the conductor pattern 32 is connected to one end of the conductor pattern 33 via the interlayer conductor 34b. Is done. The other end of the conductor pattern 33 is connected to the ground GND. The second center electrode L2 includes

conductor patterns

41 and 43 provided on the upper surface, a conductor pattern 42 provided on the lower surface, and interlayer conductors 44a and 44b provided on the side surfaces, and one end of the conductor pattern 41 is connected to the port P2. The other end of the conductor pattern 41 is connected to one end of the conductor pattern 42 via the interlayer conductor 44a, and the other end of the conductor pattern 42 is connected to one end of the conductor pattern 43 via the interlayer conductor 44b. The other end of the conductor pattern 43 is connected to the ground GND.

The third center electrode L3 includes

conductor patterns

51 and 53 provided on the upper surface, a conductor pattern 52 provided on the lower surface, and interlayer conductors 54a and 54b provided on the side surfaces, and one end of the conductor pattern 51 is connected to the port P3. The other end of the conductor pattern 51 is connected to one end of the conductor pattern 52 via the interlayer conductor 54a, and the other end of the conductor pattern 52 is connected to one end of the conductor pattern 53 via the interlayer conductor 54b. The other end of the conductor pattern 53 is connected to the ground GND. The fourth center electrode L4 includes

conductor patterns

61 and 63 provided on the upper surface, a conductor pattern 62 provided on the lower surface, and

interlayer conductors

64a and 64b provided on the side surfaces. 1), the other end of the conductor pattern 61 is connected to one end of the conductor pattern 62 via the interlayer conductor 64a, and the other end of the conductor pattern 62 is connected to one end of the conductor pattern 63 via the interlayer conductor 64b. ing. The other end of the conductor pattern 63 is connected to the ground GND.

Here, one turn in which the center electrodes L1 to L4 are wound around the ferrite 10 means a state where the ferrite 10 is wound once. However, it is sufficient that the winding is substantially performed. For example, at the center electrode L1, at least the pattern 31, the interlayer conductor 34a, and the pattern 32 are referred to as one turn.

The operation of the 4-port type circulator having the above configuration is basically the same as that of the conventional 3-port type, and the high-frequency signal input from the first input / output port P1 (transmission port TX) is the second. A high-frequency signal output from the input / output port P2 (antenna port ANT) and input from the second input / output port P2 (antenna port ANT) is output from the third input / output port P3 (reception port RX).

The first matching capacitor elements C1, C2, and C3 form part of different parallel resonance circuits with the first, second, and third center electrodes L1, L2, and L3, respectively (inductance element L11 and capacitor element C11). The operation frequency is adjusted according to each capacitance value. The first, second, and third center electrodes L1, L2, and L3 are wound around the ferrite 10 by 1.5 turns, respectively, and the insertion loss and isolation characteristics are broadened by increasing the impedance.

Then, the second matching capacitor element CS1 is inserted between the first input / output port P1 (transmission port TX) and the first center electrode L1, and the second input / output port P2 (antenna port ANT) and the second input The second matching capacitor element CS2 is inserted between the center electrode L2 and the second matching capacitor element CS3 is inserted between the third input / output port P3 (reception port RX) and the third center electrode L3. The impedances of the ports P1, P2, and P3 can be easily adjusted by the capacitance values of the second matching capacitors CS1, CS2, and CS3, and deterioration of insertion loss in the operating frequency band as a circulator can be suppressed. . Thereby, the design freedom of center electrode L1, L2, L3 improves. Furthermore, by adjusting the inductance values of the center electrodes L1, L2, and L3 and the capacitance values of the first matching capacitor elements C1, C2, and C3, the attenuation amount of the insertion loss characteristic and the isolation characteristic can be freely adjusted in the operating frequency band. Can be designed.

Here, the characteristics in the first embodiment are shown in FIG. 3 and FIG. FIG. 3 shows the isolation characteristics between ports P3 and P1 (see solid line) and the isolation characteristics between ports P1 and P3 (see dotted line). Obtaining an isolation characteristic of -20 dB or more over a wide band of 1700 MHz or more. Yes. From this result, by providing the fourth center electrode L4, the isolation characteristic between the other end portions (ports) of the two other center electrodes L1 and L3 facing each other across the center electrode L4 is improved over a wide band. I can confirm.

By the way, in the first embodiment, as shown in FIG. 2, the first center electrode L1 and the third center electrode L3 are opposed to each other, and are opposite to each other with the ground GND side as an end point (arrows a, a '). The second center electrode L2 and the fourth center electrode L4 face each other and are wound in opposite directions (see b and b ′) with the ground GND side as an end point. The first center electrode L1 and the third center electrode L3 are arranged in parallel to each other, the second center electrode L2 and the fourth center electrode L4 are arranged in parallel to each other, and the first and third center electrodes L1 and L3 and the second and fourth center electrodes L2 and L4 intersect each other at 90 °.

The opposing first center electrode L1 and third central electrode L3 are wound in opposite directions, and the opposing second center electrode L2 and fourth center electrode L4 are wound in opposite directions. Therefore, as shown in FIG. 4A, the insertion loss characteristic and the isolation characteristic between the ports P1 and P2 show good characteristics over a wide band. On the other hand, the first center electrode L1 and the third center electrode L3 facing each other are wound in the same direction, and the second center electrode L2 and the fourth center electrode L4 facing each other are wound in the same direction. In this case (comparative example), the insertion loss characteristic and the isolation characteristic between the port P1 and the port P2 are as shown in FIG. 4B, and irreversibility cannot be obtained.

By obtaining an isolation characteristic of −20 dB or more over a wide band, the irreversible circuit element 1A can simultaneously support a plurality of frequency bands used for wireless communication.

(Example of high-frequency module, see Fig. 5)
FIG. 5 shows a block diagram of a high-frequency module for a mobile phone including the nonreciprocal circuit element 1A. The first input / output port P1 (transmission port TX) is connected to the transmission filter 81 and further connected to the transmission circuit 83 via the power amplifier 82. The second input / output port P <b> 2 (antenna port ANT) is connected to the antenna 84. The third input / output port P3 (reception port RX) is connected to the reception filter 85 and further connected to the reception circuit 86.

The transmission signal output from the transmission circuit 83 is input to the antenna 84 from the nonreciprocal circuit element 1A. Then, the transmission signal reflected by the antenna 84 is reflected again by the reception filter 85, and this re-reflection signal is absorbed by the fourth input / output port P4 (resistive element R). The reception signal input from the antenna 84 is input from the third input / output port P3 to the reception circuit 86 via the reception filter 85.

(Refer to the second embodiment, FIGS. 6 and 7)
As shown in FIG. 6, the nonreciprocal circuit device 1B according to the second embodiment has basically the same configuration as that of the first embodiment, and the first center electrode L1, counterclockwise in the drawing, A second center electrode L2, a third center electrode L3, and a fourth center electrode L4 are disposed. The difference is that instead of the resistor element R, the first matching capacitor element C4 and the second matching capacitor element CS4 are connected to the other end of the fourth center electrode L4. The second input / output port P2 which is the other end of the second center electrode L2 is an antenna port ANT1, and the third input / output port P3 which is the other end of the third center electrode L3 is a second antenna port. ANT2. The fourth input / output port P4, which is the other end of the fourth center electrode L4, is a reception port RX.

The operation of the second embodiment is basically the same as that of the first embodiment, but the antenna connected to the antenna port ANT1 functions as a transmission-dedicated antenna, and is connected to the second antenna port ANT2. The connected antenna functions as a transmission / reception antenna. That is, the high-frequency signal input from the first input / output port P1 (transmission port TX) is output from the second input / output port P2 (antenna port ANT1). On the other hand, a high-frequency signal input from the third input / output port P3 (second antenna port ANT2) is output from the fourth input / output port P4 (reception port RX).

When the environment around the transmission-only antenna connected to the antenna port ANT1 changes, for example, when a person's hand, face, or head approaches the antenna, the impedance changes, and a high-frequency signal input from the transmission port TX Is reflected by the transmission-dedicated antenna.

In the nonreciprocal circuit element 1B, since the second antenna port ANT2 is provided between the antenna port ANT1 and the reception port RX, the high frequency signal reflected by the transmission dedicated antenna is connected to the port P3 (ANT2). Output from the transmitting / receiving antenna. For this reason, it is possible to prevent the high frequency signal input from the transmission port TX from leaking to the reception port RX due to the impedance variation of the antenna connected to the antenna port ANT1, and the isolation between the ports P1 and P4 from deteriorating. Can do.

Specifically, as shown in FIG. 7A, when the voltage standing wave ratio (VSWR) of the transmission-dedicated antenna connected to the antenna port ANT1 is 3, the antenna impedance is a, b, c, d, FIG. 7B shows a change in isolation between the ports P1 to P4 (TX-RX) when changed to e and f. On the other hand, FIG. 7C shows the isolation characteristic between the ports P1-P3 (TX-RX) when the impedance in the conventional example shown in FIG. 16 changes from a to f. As is clear from the comparison of the graphs of FIGS. 7B and 7C, in the example of the present invention, an isolation characteristic of −15 dB or more is obtained in the frequency band of 699 to 960 MHz. In the conventional example in which the second antenna port ANT2 is not provided between the receiving port RX and the receiving port RX, it is greatly deteriorated.

The antenna connected to the antenna port ANT1 may correspond to the transmission signal and the reception signal, and the antenna connected to the second antenna port ANT2 may correspond to only the transmission signal.

(Refer to antenna arrangement and operation mode, Fig. 8 and Fig. 9)
As shown in FIG. 8, in the mobile terminal 100, the antenna 105 connected to the antenna port ANT1 is vertically arranged on the top of the housing 101, and the antenna 106 connected to the second antenna port ANT2 is placed in the housing 101. You may make it arrange | position horizontally at the lower part of. In other words, it is preferable that the installation positions of the

antennas

105 and 106 are separated in the housing 101 and are different from each other in terms of avoiding mutual interference and different impedance variations.

Further, as shown in FIGS. 9A and 9B, a surface-mounted antenna 121 is disposed as a first antenna on a circuit board 110 provided with a ground electrode 111, and a whip antenna 122 is disposed as a second antenna. It may be arranged. In the arrangement example shown in FIG. 9A, the surface-mounted antenna 121 is mounted such that the open end of the radiation electrode faces downward, so that the open end is kept away from the whip antenna 122. In the arrangement example shown in FIG. 9B, the surface-mounted antenna 121 is mounted so that the open end of the radiation electrode faces the outside of the mobile terminal 100, so that the open end is kept away from the whip antenna 122. Yes. In any arrangement example, mutual interference between the surface-mounted antenna 121 and the whip antenna 122 is prevented.

In addition, by changing the types of the first antenna and the second antenna, changing the operation mode, or separating the antennas, the impedance of the first antenna and the second antenna can be changed due to environmental changes at the same time. Can be avoided.

(Refer to the third embodiment, FIG. 10)
As shown in FIG. 10, the nonreciprocal circuit device 1C according to the third embodiment has basically the same configuration as that of the second embodiment (see FIG. 6). These antennas correspond to both transmission signals and reception signals, and a filter F is inserted between the other end of the third center electrode L3 and the port P3. The filter F may have either a fixed or variable pass characteristic. The filter F passes a high-frequency signal input from the transmission port TX and reflected by the first antenna, and reflects a received signal of the first antenna. Has filter characteristics.

In the third embodiment, a high-frequency signal input from the first input / output port P1 (transmission port TX) is output from the second input / output port P2 (antenna port ANT1). This transmission signal is selected from a plurality of frequency bands according to need.

Further, even if a part of the high-frequency signal input from the transmission port TX is reflected by the antenna connected to the port P2 (ANT1), it passes through the filter F and is output to the port 3 (ANT2). A second antenna is connected to port 3, and a signal reflected by the first antenna is output from the second antenna. For this reason, even if the environment around the antenna changes and the impedance fluctuates, it is possible to prevent the deterioration of the isolation characteristics between the ports P1 and P4 as much as possible. This effect is the same as that of the second embodiment.

On the other hand, the received signal input from the antenna connected to the port P2 (ANT1) is reflected by the filter F and input to the port P4 (receiving port RX).

In addition, when connecting a 2nd antenna to the port P3, the 2nd antenna should just respond | correspond only to a transmission signal at least.

(Refer to the fourth embodiment, FIGS. 11 to 14)
As shown in FIG. 11, the nonreciprocal circuit device 1D according to the fourth embodiment basically has the same configuration as that of the third embodiment (see FIG. 10). The resistance element R dropped to the ground is connected to the other end of the center electrode L3 through the filter F. Therefore, the port P3 is a termination, and the antenna port is only the port P2. As in the third embodiment, the filter F may have either a fixed or variable pass characteristic, and passes a high-frequency signal input from the transmission port TX and reflected by the antenna, It has a filter characteristic to reflect. The antenna is compatible with both transmission signals and reception signals.

In the fourth embodiment, a high-frequency signal input from the first input / output port P1 (transmission port TX) is output from the second input / output port P2 (antenna port ANT). As in the third embodiment, the transmission signal is selected from a plurality of frequency bands as required.

Further, even if a part of the high frequency signal input from the transmission port TX is reflected by the antenna connected to the port P2 (ANT), it passes through the filter F and is absorbed by the resistance element R. For this reason, even if the environment around the antenna changes and the impedance fluctuates, it is possible to prevent the deterioration of the isolation characteristics between the ports P1 and P4 as much as possible. This effect is the same as in the second and third embodiments.

On the other hand, the received signal input from the antenna connected to the port P2 (ANT) is reflected by the filter F and input to the port P4 (receiving port RX).

Here, FIG. 12 shows a block diagram of a high-frequency module constituting a front-end circuit including the nonreciprocal circuit element 1D. The first input / output port P1 (transmission port TX) is connected to the transmission circuit 83 via the power amplifier 82. The second input / output port P <b> 2 (antenna port ANT) is connected to the antenna 84. The third input / output port P3 is connected to the other end of the third center electrode L3 via the filter F and the resistance element R. The fourth input / output port P4 (reception port RX) is connected to the reception circuit 86.

Although omitted in FIG. 12, filters may be arranged between the first input / output port P1 and the power amplifier 82 and between the fourth input / output port P4 and the receiving circuit 86.

The transmission signal output from the transmission circuit 83 is input to the antenna 84 from the first input / output port P1. Then, the transmission signal reflected by the antenna 84 passes through the filter F and is absorbed by the resistance element R. The reception signal input from the antenna 84 is reflected by the filter F and input to the reception circuit 86 from the fourth input / output port P4.

In FIG. 13, when the voltage standing wave ratio (VSWR) of the antenna 84 is 3 as in FIG. 7B, the impedance of the antenna changes to a, b, c, d, e, f. The change in isolation between ports P1-P4 (TX-RX) is shown. A conventional example to be compared is FIG. 7C, and in the band of 699 to 960 MHz, the isolation characteristic of -15 dB or more is obtained in the example of the present invention.

When the VSWR of the antenna 84 is 1.5, 2.0, 3.0, 6.0, the isolating between the ports P1-P4 (TX-RX) when the impedance of the antenna 84 is changed by the respective VSWR values. FIG. 14A shows the change in the adjustment. On the other hand, FIG. 14B shows a similar change in isolation in the conventional example shown in FIG. As is clear from the comparison of the graphs of FIGS. 14A and 14B, the isolation characteristics of the example of the present invention are greatly improved at any impedance compared to the conventional example. For example, when VSWR is 3.0, the isolation is −7.3 to −8.3 dB in the conventional example, whereas it is −15.4 to −19.7 dB in the example of the present invention. Also, when the VSWR is 1.0, the isolation characteristics of the present invention are not significantly deteriorated as compared with the conventional example. Therefore, even when the VSWR varies, by using the configuration of the present invention example, excellent isolation characteristics between TX and RX can be obtained over a wide frequency band.

In addition, as shown in FIG. 15, it is good also as a high frequency module using other multiple port devices 2 provided with the port for transmission TX, the port for reception RX, and the port for antenna ANT instead of a nonreciprocal circuit element. The other multi-port device 2 is, for example, a CMOS duplexer using a transformer.

With the structure shown in FIG. 15, the transmission signal reflected by the load fluctuation of the antenna 84 can be absorbed by the resistance element R (may be a variable resistance element), and the reflected signal is transmitted to the reception circuit 86 side. It can prevent wrapping around. As a result, similar to the non-reciprocal circuit element, an effect of preventing deterioration of isolation between transmission and reception can be obtained.

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

For example, the specific shape of the center electrode is arbitrary. Further, the matching capacitor element may be built in the circuit board or may be mounted on the circuit board as a chip type.

As described above, the present invention is useful for non-reciprocal circuit elements and high-frequency modules. Particularly, a large value of isolation characteristics can be obtained in a wide band, and even if the impedance of the antenna fluctuates, the isolation characteristics can be obtained. It is excellent in that deterioration can be prevented.

1A-1D ... Non-reciprocal circuit element (circulator)
DESCRIPTION OF SYMBOLS 10 ... Ferrite 81 ... Transmission filter 83 ... Transmission circuit 84 ... Antenna 85 ... Reception filter 86 ... Reception circuit 100 ... Portable terminal 105,106 ... Antenna 121 ... Surface mount type antenna 122 ... Whip antenna L1-L4 ... Center electrode C1-C4 ... Capacitor elements CS1 to CS4 ... Capacitor elements R, R1 to R3 ... Resistance elements F ... Filters P1 to P4 ... Ports

Claims

With ferrite,
First, second, third, and fourth center electrodes, each of which is arranged to be wound around the ferrite in at least one turn in an insulated state, and each one end of which is connected to the ground,
A first matching capacitor element connected to each of the other ends of the first, second and third center electrodes and connected to the ground;
Between the other end of the first center electrode and the first input / output port, between the other end of the second center electrode and the second input / output port, and between the other end of the third center electrode and the third input A second matching capacitor element connected to the output port;
A non-reciprocal circuit device comprising:
The nonreciprocal circuit device according to claim 1, further comprising a resistance element connected to the other end of the fourth center electrode and connected to the ground.
The first center electrode and the third center electrode face each other and are wound in opposite directions;
The second center electrode and the fourth center electrode are opposed to each other and wound in opposite directions;
The nonreciprocal circuit device according to claim 1, wherein
The first center electrode and the third center electrode are arranged in parallel to each other, the second center electrode and the fourth center electrode are arranged in parallel to each other, and the first, third center electrode, second, fourth The nonreciprocal circuit device according to any one of claims 1 to 3, wherein the center electrodes intersect each other at 90 °.
A nonreciprocal circuit device according to any one of claims 1 to 4,
The first input / output port is a transmission port, the second input / output port is an antenna port, and the third input / output port is a reception port;
High frequency module characterized by
6. The high frequency module according to claim 5, wherein the first input / output port is connected to a transmission filter, the second input / output port is connected to an antenna, and the third input / output port is connected to a reception filter. .
With ferrite,
First, second, third, and fourth center electrodes, each of which is arranged to be wound around the ferrite in at least one turn in an insulated state, and each one end of which is connected to the ground,
A first matching capacitor element connected to the other end of each of the first, second, third and fourth center electrodes and connected to the ground;
Between the other end of the first center electrode and the first input / output port, between the other end of the second center electrode and the second input / output port, and the other end of the third center electrode and the third input / output port And a second matching capacitor element connected between the other end of the fourth center electrode and the fourth input / output port,
A non-reciprocal circuit device comprising:
The nonreciprocal circuit device according to claim 7, wherein a filter is connected to the other end of the third center electrode.
A nonreciprocal circuit device according to claim 7 or 8,
The first input / output port is a transmission port, the second input / output port is a first antenna port, the third input / output port is a second antenna port, and the fourth input / output port is a reception port. ,
High frequency module characterized by
The high-frequency module according to claim 9, wherein the antenna connected to the first antenna port corresponds to a transmission signal and a reception signal, and the antenna connected to the second antenna port corresponds to only a transmission signal. .
The high-frequency module according to claim 9, wherein the antenna connected to the first antenna port corresponds only to a transmission signal, and the antenna connected to the second antenna port corresponds to a transmission signal and a reception signal. .
The high-frequency module according to any one of claims 9 to 11, wherein the antenna connected to the first antenna port and the antenna connected to the second antenna port have different operation modes.
The high-frequency module according to any one of claims 9 to 12, wherein an antenna connected to the first antenna port and an antenna connected to the second antenna port have different installation positions.
With ferrite,
First, second, third, and fourth center electrodes, each of which is arranged to be wound around the ferrite in at least one turn in an insulated state, and each one end of which is connected to the ground,
A first matching capacitor element connected to the other end of each of the first, second and fourth center electrodes and connected to the ground;
Between the other end of the first center electrode and the first input / output port, between the other end of the second center electrode and the second input / output port, and between the other end of the fourth center electrode and the fourth input A second matching capacitor element connected to the output port;
A resistance element connected to the other end of the third center electrode and connected to the ground;
A filter having a fixed or variable pass characteristic connected between the other end of the third center electrode and the resistance element;
A non-reciprocal circuit device comprising:
A nonreciprocal circuit device according to claim 14,
The first input / output port is a transmission port, the second input / output port is an antenna port, and the fourth input / output port is a reception port;
High frequency module characterized by
16. The high-frequency module according to claim 15, wherein the first input / output port is connected to a transmission circuit, the second input / output port is connected to an antenna, and the fourth input / output port is connected to a reception circuit. .