JP2017038114A - Directional coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a directional coupler that can be used in broadband while having bidirectionality.SOLUTION: A directional coupler 1 includes first through fourth ports 11, 12, 13, 14, a main line 10 connecting the first port 11 and a second port 12, first through fourth sub-lines 20A, 20B, 20C, 20D electromagnetic field coupling to the main line 10, respectively, and first through third matching sections 30A, 30B, 30C. The first sub-line 20A is connected with the third port 13. The second sub-line 20B is connected with the fourth port 14. The first matching section 30A is provided between the first sub-line 20A and third sub-line 20C. The second matching section 30B is provided between the second sub-line 20B and fourth sub-line 20D. The third matching section 30C is provided between the third sub-line 20C and fourth sub-line 20D.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a directional coupler that can be used in a wide band.

  The directional coupler is used for detecting the level of a transmission / reception signal in a transmission / reception circuit of a wireless communication device such as a mobile phone or a wireless LAN communication device.

  As a conventional directional coupler, one having the following configuration is known. The directional coupler includes an input port, an output port, a coupling port, a termination port, a main line, and a sub line. One end of the main line is connected to the input port, and the other end of the main line is connected to the output port. One end of the sub line is connected to the coupling port, and the other end of the sub line is connected to the termination port. The main line and the sub line are electromagnetically coupled. The termination port is grounded via a termination resistor having a resistance value of 50Ω, for example. A high frequency signal is input to the input port, and this high frequency signal is output from the output port. From the coupling port, a coupling signal having power corresponding to the power of the high-frequency signal input to the input port is output.

  The main parameters representing the characteristics of the directional coupler include coupling degree, isolation, and reflection loss of the coupling port. Hereinafter, these definitions will be described. First, when a high-frequency signal having power P1 is input to the input port, the power of the signal output from the coupling port is P3. Further, when a high-frequency signal with power P02 is input to the output port, the power of the signal output from the coupling port is P03. Further, when a high-frequency signal having power P5 is input to the coupling port, the power of the signal reflected by the coupling port is P6. Further, the degree of coupling, isolation, and reflection loss of the coupling port are represented by symbols C, I, and RL, respectively. These are defined by the following equations.

C = 10 log (P3 / P1) [dB]
I = 10 log (P03 / P02) [dB]
RL = 10 log (P6 / P5) [dB]

  The conventional directional coupler has a problem in that the frequency characteristic of the coupling degree is not flat because the coupling degree increases as the frequency of the high-frequency signal input to the input port increases. The increase in the degree of coupling means that the value of c decreases when the degree of coupling is expressed as -c (dB).

  Patent Document 1 describes a directional coupler for solving the above problem. In the directional coupler described in Patent Document 1, the sub line is divided into a first sub line and a second sub line. One end of the first sub line is connected to the coupling port. One end of the second subline is connected to the termination port. A phase converter is provided between the other end of the first sub-line and the other end of the second sub-line. The phase conversion unit causes the passing signal to have a phase shift having an absolute value that monotonously increases in a range of 0 degrees to 180 degrees as the frequency increases in a predetermined frequency band. Specifically, the phase converter is a low-pass filter.

  By the way, in recent years, a mobile communication system based on the LTE (Long Term Evolution) standard has been put into practical use, and a mobile communication system based on the LTE-Advanced standard, which is an evolution standard of the LTE standard, has been studied. One of the main technologies in the LTE-Advanced standard is carrier aggregation (hereinafter also referred to as CA). CA is a technology that enables broadband transmission by simultaneously using a plurality of carriers called component carriers.

  In a mobile communication device that supports CA, a plurality of frequency bands are used simultaneously. Therefore, a mobile communication device compatible with CA is required to have a directional coupler that can be used for a plurality of signals in a plurality of frequency bands, that is, a directional coupler that can be used in a wide band.

  In addition, in a directional coupler used in a wireless communication device, even if the input port and the output port are reversed and the coupling port and the termination port are reversed, the same characteristics as before the reversal can be obtained. (Hereinafter referred to as bidirectionality) may be required. As an example where this bidirectionality is required, the level of the transmission signal is detected by a directional coupler provided in the transmission system circuit that supplies the transmission signal to the antenna, and the transmission signal is reflected by the antenna. The case where the level of the generated reflected wave signal is detected is mentioned. The reason for detecting the level of the reflected wave signal by the directional coupler is to adjust the characteristics of the impedance matching element provided between the transmission circuit and the antenna so that the level of the reflected wave signal becomes sufficiently small. is there. In this example, when the level of the transmission signal is detected by the directional coupler, the transmission signal is input to the input port and output from the output port, and a signal having power corresponding to the level of the transmission signal is output from the coupling port. Is output. On the other hand, when the level of the reflected wave signal is detected by the directional coupler, the reflected wave signal is input to the output port and output from the input port, and the signal has power corresponding to the level of the reflected wave signal from the termination port. Is output.

  Patent Document 2 describes a directional coupler that can be used in a wide band and has bidirectionality. In the directional coupler described in Patent Document 2, the sub-line includes a first coupling part that is strongly coupled to the main line, and a second coupling part that is weakly coupled and formed closer to the coupling port than the first coupling part. The coupling is weak and the third coupling part formed on the isolation port (termination port) side of the first coupling part, and extends between the first coupling part and the second coupling part and corresponds to the used frequency band A first non-coupled portion that is a non-coupled portion having a length of one quarter or more of the measured wavelength, and a wavelength four corresponding to the used frequency band and extending between the first coupled portion and the third coupled portion. And a second non-bonded portion that is a non-bonded portion having a length of one or more minutes.

JP 2013-5076 A JP 2014-57207 A

  In the directional coupler described in Patent Document 1, the isolation is not sufficiently large in the frequency band equal to or higher than the cutoff frequency of the low-pass filter. That is, when the isolation is expressed as -i (dB), in the directional coupler described in Patent Document 1, the value of i is not sufficiently large in the frequency band equal to or higher than the cutoff frequency of the low-pass filter. Therefore, the directional coupler described in Patent Document 1 does not function in a frequency band higher than the cutoff frequency of the low-pass filter.

  Here, in the directional coupler described in Patent Document 1, the reason why the value of i is not sufficiently large in the frequency band equal to or higher than the cutoff frequency of the low-pass filter will be described. In this directional coupler, a path connecting the connection point between the first sub-line and the low-pass filter and the ground via only the first capacitor, and a connection point between the second sub-line and the low-pass filter. A path is formed to connect the ground and the ground via only the second capacitor. Therefore, in a frequency band equal to or higher than the cutoff frequency of the low-pass filter, most of the high-frequency signal from the first sub line to the low-pass filter flows to the ground via the first capacitor, and the low-pass filter from the second sub line. Most of the high-frequency signal that goes to flows through the second capacitor to the ground. Therefore, in this directional coupler, most of the high-frequency signal does not pass through the low-pass filter in the frequency band equal to or higher than the cutoff frequency of the low-pass filter.

  From the above, in the directional coupler described in Patent Document 1, the usable frequency band is limited to a frequency band lower than the cutoff frequency of the low-pass filter. Therefore, with the technique described in Patent Document 1, it is difficult to realize a directional coupler that can be used in a wide band.

  In the directional coupler described in Patent Document 2, one attenuation pole is generated in the frequency characteristic of the degree of coupling. As a result, it is possible to suppress a change in the degree of coupling that accompanies a change in frequency in a somewhat wide frequency band. However, in this directional coupler, in the frequency characteristic of the degree of coupling, the degree of coupling increases as the frequency increases in a frequency region higher than the frequency at which one attenuation pole occurs. Therefore, in this directional coupler, it is difficult to suppress a change in the degree of coupling accompanying a change in frequency in a wider frequency band.

  The present invention has been made in view of such problems, and an object thereof is to provide a directional coupler that can be used in a wide band and has bidirectionality.

  The directional coupler according to the present invention includes a first port, a second port, a third port, a fourth port, a main line connecting the first port and the second port, and A first sub-line unit, a second sub-line unit, and a third sub-line unit that are composed of lines that are electromagnetically coupled to the main line and that have first and second ends located opposite to each other. A line section and a fourth sub line section, a first matching section, a second matching section, and a third matching section are provided.

  The first end portion of the first sub line portion is connected to the third port. The first end of the second subline portion is connected to the fourth port. The first matching portion is provided between the second end portion of the first sub line portion and the first end portion of the third sub line portion. The second matching portion is provided between the second end portion of the second sub line portion and the first end portion of the fourth sub line portion. The third matching portion is provided between the second end portion of the third sub line portion and the second end portion of the fourth sub line portion. Each of the first to third matching sections causes a phase change with respect to a signal passing therethrough.

  In the directional coupler according to the present invention, the third and fourth sub-line portions may have higher coupling strength with respect to the main line than the first and second sub-line portions. In addition, the third matching unit may have a smaller phase change to be generated with respect to a signal having the same frequency than the first and second matching units.

  In the directional coupler according to the present invention, each of the first matching portion and the second matching portion includes a first path connecting the first end portion and the second end portion, And a second path connecting the path and the ground. The first path includes a first inductor. The second path includes a first capacitor and a second inductor connected in series. The third matching unit may be a line.

  The first inductor has a first end and a second end located on opposite sides, and the second inductor is a first end closest to the first path in terms of circuit configuration. And a second end closest to the ground in circuit configuration, and the first capacitor is formed between the first end of the first inductor and the first end of the second inductor. It may be provided between them. In this case, the second path may further include a second capacitor provided between the second end of the first inductor and the first end of the second inductor. .

  According to the directional coupler of the present invention, the frequency change occurs in a wider frequency band as compared with the directional coupler having a configuration in which the number of sub-line portions electromagnetically coupled to the main line is three or less. It becomes possible to suppress a change in the degree of coupling. In addition, the directional coupler of the present invention can have a symmetric or nearly symmetric circuit configuration. Therefore, according to the present invention, it is possible to realize a directional coupler that can be used in a wide band and has bidirectionality.

It is a circuit diagram which shows the circuit structure of the directional coupler which concerns on one embodiment of this invention. It is a circuit diagram which shows the usage example of the directional coupler which concerns on one embodiment of this invention. It is a perspective view of the directional coupler which concerns on one embodiment of this invention. It is a perspective view which shows the inside of the laminated body of the directional coupler shown in FIG. It is sectional drawing of the laminated body of the directional coupler shown in FIG. FIG. 4 is an explanatory view showing one surface of the first to fourth dielectric layers in the laminated body of the directional coupler shown in FIG. 3. FIG. 4 is an explanatory diagram showing one surface of the fifth to eighth dielectric layers in the stacked body of the directional coupler shown in FIG. 3. FIG. 4 is an explanatory view showing one surface of the ninth to twelfth dielectric layers in the laminated body of the directional coupler shown in FIG. 3. FIG. 4 is an explanatory diagram showing one surface of the thirteenth to sixteenth dielectric layers in the laminated body of the directional coupler shown in FIG. 3. FIG. 4 is an explanatory view showing one surface of 17th to 20th dielectric layers in the laminated body of the directional coupler shown in FIG. 3. FIG. 4 is an explanatory view showing one surface of the twenty-first to twenty-third dielectric layers in the laminated body of the directional coupler shown in FIG. 3. It is a characteristic view which shows the frequency characteristic of each single coupling degree of the 1st and 2nd coupling | bond part in the directional coupler shown in FIG. It is a characteristic view which shows the frequency characteristic of each phase change amount of the 1st and 2nd matching part in the directional coupler shown in FIG. It is a characteristic view which shows the frequency characteristic of the phase change amount of the 3rd matching part in the directional coupler shown in FIG. It is a circuit diagram which shows the coupler part which is a part of the directional coupler shown in FIG. It is a characteristic view which shows the frequency characteristic of the coupling degree of the coupler part shown in FIG. It is a circuit diagram which shows the center coupling | bond part of a comparative example. It is a characteristic view which shows the frequency characteristic of the coupling degree of the center coupling | bond part shown in FIG. It is a characteristic view which shows the frequency characteristic of the coupling degree of the directional coupler of a comparative example. It is a characteristic view which shows the frequency characteristic of the coupling degree of the directional coupler which concerns on one embodiment of this invention. It is a characteristic view which shows the frequency characteristic of isolation of the directional coupler which concerns on one embodiment of this invention. It is a characteristic view which shows the frequency characteristic of the reflection loss of the coupling port of the directional coupler which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a circuit configuration of a directional coupler according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the directional coupler 1 according to the present embodiment includes a first port 11, a second port 12, a third port 13, and a fourth port 14. ing. The directional coupler 1 further includes a main line 10 that connects the first port 11 and the second port 12, and a first sub-line unit 20 </ b> A including a line that is electromagnetically coupled to the main line 10. The second sub-line portion 20B, the third sub-line portion 20C and the fourth sub-line portion 20D, a first matching portion 30A, a second matching portion 30B, and a third matching portion 30C are provided. ing. One of the third port 13 and the fourth port 14 is grounded via a termination resistor having a resistance value of 50Ω, for example.

  The first sub-line portion 20A has a first end portion 20A1 and a second end portion 20A2 that are located on opposite sides. The second sub line portion 20B has a first end portion 20B1 and a second end portion 20B2 that are located on opposite sides. The third sub-line portion 20C has a first end portion 20C1 and a second end portion 20C2 that are located on opposite sides. The fourth sub line portion 20D has a first end portion 20D1 and a second end portion 20D2 that are located on opposite sides. The first alignment portion 30A has a first end portion 30A1 and a second end portion 30A2 that are located on opposite sides. The second alignment portion 30B has a first end 30B1 and a second end 30B2 that are located on opposite sides. The third alignment portion 30C has a first end 30C1 and a second end 30C2 that are located on opposite sides.

  The first end 20 </ b> A <b> 1 of the first subline portion 20 </ b> A is connected to the third port 13. The first matching portion 30A is provided between the second end 20A2 of the first sub line portion 20A and the first end 20C1 of the third sub line portion 20C. The first end 30A1 of the first matching portion 30A is connected to the second end 20A2 of the first subline portion 20A. The first end 20C1 of the third sub-line portion 20C is connected to the second end 30A2 of the first matching portion 30A.

  The first end 20 </ b> B <b> 1 of the second sub line portion 20 </ b> B is connected to the fourth port 14. The second matching portion 30B is provided between the second end 20B2 of the second subline portion 20B and the first end 20D1 of the fourth subline portion 20D. The first end 30B1 of the second matching portion 30B is connected to the second end 20B2 of the second sub line portion 20B. The first end 20D1 of the fourth sub line portion 20D is connected to the second end 30B2 of the second matching portion 30B.

  The third matching portion 30C is provided between the second end 20C2 of the third subline portion 20C and the second end 20D2 of the fourth subline portion 20D. In the present embodiment, the third matching unit 30C is a line. The first end 30C1 of the third matching portion 30C is connected to the second end 20C2 of the third subline portion 20C. The second end 30C2 of the third matching portion 30C is connected to the second end 20D2 of the fourth subline portion 20D.

  The first matching section 30A includes a first path 31A that connects the first end 30A1 and the second end 30A2, and a second path 32A that connects the first path 31A and the ground. have. The first path 31A includes a first inductor L1A. The first inductor L1A has a first end L1A1 and a second end L1A2 located on opposite sides. Here, the end of the first inductor L1A on the first sub-line portion 20A side is defined as a first end L1A1, and the end of the first inductor L1A on the third sub-line portion 20C side is defined as a second end. Let it be an end L1A2.

  The second path 32A includes a first capacitor C1A and a second inductor L2A connected in series. The second inductor L2A has a first end L2A1 that is closest to the first path 31A in the circuit configuration, and a second end L2A2 that is closest to the ground in the circuit configuration. The first capacitor C1A is provided between the first end L1A1 of the first inductor L1A and the first end L2A1 of the second inductor L2A. In the present embodiment, the second path 32A is further provided with a second end provided between the second end L1A2 of the first inductor L1A and the first end L2A1 of the second inductor L2A. It has a capacitor C2A. The second inductor L2A has an inductance of 0.1 nH or more. The inductance of the second inductor L2A is preferably 7 nH or less.

  The circuit configuration of the second matching unit 30B is the same as that of the first matching unit 30A. That is, the second matching unit 30B includes a first path 31B that connects the first end 30B1 and the second end 30B2, and a second path that connects the first path 31B and the ground. 32B. The first path 31B includes a first inductor L1B. The first inductor L1B has a first end L1B1 and a second end L1B2 located on opposite sides. Here, the end portion of the first inductor L1B on the second subline portion 20B side is defined as the first end portion L1B1, and the end portion of the first inductor L1B on the fourth subline portion 20D side is defined as the second end portion. Let it be an end L1B2.

  The second path 32B includes a first capacitor C1B and a second inductor L2B connected in series. The second inductor L2B has a first end L2B1 that is closest to the first path 31B in the circuit configuration, and a second end L2B2 that is closest to the ground in the circuit configuration. The first capacitor C1B is provided between the first end L1B1 of the first inductor L1B and the first end L2B1 of the second inductor L2B. In the present embodiment, the second path 32B is further provided with a second end provided between the second end L1B2 of the first inductor L1B and the first end L2B1 of the second inductor L2B. It has a capacitor C2B. The second inductor L2B has an inductance of 0.1 nH or more. The inductance of the second inductor L2B is preferably 7 nH or less.

  Here, a portion where the main line 10 and the first sub line portion 20A are coupled to each other is referred to as a first coupling portion 40A. A portion where the main line 10 and the second sub line portion 20B are coupled to each other is referred to as a second coupling portion 40B. A portion of the main line 10 and the third sub line portion 20C that are coupled to each other is referred to as a third coupling portion 40C. Further, a portion where the main line 10 and the fourth sub line portion 20D are coupled to each other is referred to as a fourth coupling portion 40D.

  Further, the strength of coupling of the first to fourth coupling portions 40A, 40B, 40C, and 40D is defined as follows. The strength of coupling of the first coupling portion 40A is the strength of coupling of the first sub-line portion 20A to the main line 10. The strength of coupling of the first coupling unit 40A can be expressed by the degree of coupling of the first coupling unit 40A. The greater the degree of single coupling of the first coupling portion 40A, the greater the strength of coupling of the first coupling portion 40A.

  The coupling strength of the second coupling portion 40B is the coupling strength of the second sub-line portion 20B with respect to the main line 10. The strength of the coupling of the second coupling part 40B can be expressed by the degree of coupling of the second coupling part 40B. The strength of the coupling of the second coupling part 40B increases as the degree of coupling of the second coupling part 40B increases.

  The coupling strength of the third coupling portion 40 </ b> C is the coupling strength of the third sub-line portion 20 </ b> C with respect to the main line 10. The strength of the coupling of the third coupling portion 40C can be expressed by the single coupling degree of the third coupling portion 40C. The greater the degree of coupling of the third coupling portion 40C, the greater the strength of coupling of the third coupling portion 40C.

  The coupling strength of the fourth coupling portion 40 </ b> D is the coupling strength of the fourth sub-line portion 20 </ b> D with respect to the main line 10. The strength of the coupling of the fourth coupling portion 40D can be represented by the single coupling degree of the fourth coupling portion 40D. The greater the degree of single coupling of the fourth coupling portion 40D, the greater the strength of coupling of the fourth coupling portion 40D.

  In the present embodiment, the third and fourth sub-line portions 20C and 20D have higher coupling strength with respect to the main line 10 than the first and second sub-line portions 20A and 20B. That is, the strength of each of the third and fourth coupling portions 40C and 40D is greater than the strength of each of the first and second coupling portions 40A and 40B.

  In the first to third matching portions 30A, 30B, and 30C, one of the third port 13 and the fourth port 14 is grounded via a termination resistor that is a load, and the resistance value of this termination resistor (for example, 50Ω) ) Is a circuit that performs impedance matching between the signal source and the load, assuming that a signal source having an output impedance equal to) is connected to the other of the third port 13 and the fourth port 14. The first to third matching units 30A, 30B, and 30C are assumed to be in the above-described case, and are used from one of the third port 13 and the fourth port 14 to the other side in the use frequency band of the directional coupler 1. Is designed so that the absolute value of the reflection coefficient is 0 or a value in the vicinity thereof. Each of the first to third matching units 30A, 30B, and 30C causes a phase change with respect to a signal passing therethrough. In the present embodiment, the third matching unit 30C has a smaller phase change that occurs with respect to signals of the same frequency than the first and second matching units 30A and 30B.

  The circuit configuration of the directional coupler 1 is preferably symmetrical about the third matching unit 30C and including the element constant. However, the circuit configuration of the directional coupler 1 may be close to symmetry even if it is not completely symmetrical.

  Hereinafter, a case where the circuit configuration of the directional coupler 1 is symmetric will be described. In this case, the coupling strength of the second coupling portion 40B is equal to the coupling strength of the first coupling portion 40A, and the coupling strength of the fourth coupling portion 40D is the coupling strength of the third coupling portion 40C. Is equal to the strength of The first and second matching portions 30A and 30B have symmetrical circuit configurations including the element constant with the third matching portion 30C as the center. More specifically, the inductances of the first inductors L1A and L1B that form a pair are substantially equal to each other, and the inductances of the second inductors L2A and L2B that form a pair are substantially equal to each other. The capacitances of the capacitors C1A and C1B are substantially equal to each other, and the capacitances of the paired second capacitors C2A and C2B are substantially equal to each other. The first and second matching units 30A and 30B cause a phase change of the same magnitude to the signal when the signal of the same frequency passes through them. Since the directional coupler 1 has a symmetric circuit configuration around the third matching portion 30C, it has bidirectionality. Note that the inductances of two inductors that are paired and the capacitances of two capacitors that are paired are “substantially equal to each other” means that errors in inductance and capacitance caused by variations in the manufacturing of inductors and capacitors are allowed. It means that.

  In the first matching unit 30A shown in FIG. 1, the first capacitor C1A is located between the first end L1A1 of the first inductor L1A and the first end L2A1 of the second inductor L2A. The second capacitor C2A is provided between the second end L1A2 of the first inductor L1A and the first end L2A1 of the second inductor L2A. Further, in the second matching unit 30B illustrated in FIG. 1, the first capacitor C1B is provided between the first end L1B1 of the first inductor L1B and the first end L2B1 of the second inductor L2B. The second capacitor C2B is provided between the second end L1B2 of the first inductor L1B and the first end L2B1 of the second inductor L2B. However, the arrangement on the circuit configuration of the first and second capacitors C1A and C2A in the first matching unit 30A, and the arrangement on the circuit configuration of the first and second capacitors C1B and C2B in the second matching unit 30B. May be opposite to the example shown in FIG. That is, in the first matching unit 30A, the first capacitor C1A is provided between the second end L1A2 of the first inductor L1A and the first end L2A1 of the second inductor L2A. Two capacitors C2A may be provided between the first end L1A1 of the first inductor L1A and the first end L2A1 of the second inductor L2A. In this case, in the second matching unit 30B, the first capacitor C1B is provided between the second end L1B2 of the first inductor L1B and the first end L2B1 of the second inductor L2B. A second capacitor C2B is provided between the first end L1B1 of the first inductor L1B and the first end L2B1 of the second inductor L2B.

  Next, the operation of the directional coupler 1 according to this embodiment will be described. The directional coupler 1 can be used in the following first and second usage modes. In the first usage mode, the first port 11 is an input port, the second port 12 is an output port, the third port 13 is a coupling port, and the fourth port 14 is a termination port. In the first usage mode, the fourth port 14 is grounded via a termination resistor having a resistance value of, for example, 50Ω. In the second usage mode, the second port 12 is an input port, the first port 11 is an output port, the fourth port 14 is a coupling port, and the third port 13 is a termination port. In the second usage mode, the third port 13 is grounded via a termination resistor having a resistance value of 50Ω, for example.

  In the first usage mode, a high frequency signal is input to the first port 11, and this high frequency signal is output from the second port 12. From the third port 13, a combined signal having power corresponding to the power of the high-frequency signal input to the first port 11 is output.

  In the first usage mode, between the first port 11 serving as an input port and the third port 13 serving as a coupling port, a first signal path passing through the first coupling unit 40A, and a third port A second signal path passing through the coupling unit 40C and the first matching unit 30A, a third signal path passing through the fourth coupling unit 40D, the third matching unit 30C, and the first matching unit 30A; A fourth signal path is formed via the second coupling portion 40B, the second matching portion 30B, the third matching portion 30C, and the first matching portion 30A. When a high-frequency signal is input to the first port 11, the combined signal output from the third port 13 is a signal obtained by synthesizing the signals that have passed through the first to fourth signal paths. The degree of coupling of the directional coupler 1 in the first usage mode is that the coupling strengths of the first to fourth coupling portions 40A, 40B, 40C, and 40D and the first to fourth signal paths respectively pass. Depending on the phase relationship of the signal.

  In the first usage mode, between the second port 12 serving as an output port and the third port 13 serving as a coupling port, a fifth signal path passing through the first coupling unit 40A, and a third port A sixth signal path passing through the coupling unit 40C and the first matching unit 30A, a seventh signal path passing through the fourth coupling unit 40D, the third matching unit 30C, and the first matching unit 30A; An eighth signal path that passes through the second coupling unit 40B, the second matching unit 30B, the third matching unit 30C, and the first matching unit 30A is formed. The isolation of the directional coupler 1 in the first usage mode passes through the coupling strengths of the first to fourth coupling portions 40A, 40B, 40C, and 40D and the fifth to eighth signal paths, respectively. Depending on the phase relationship of the signal.

  In the second usage mode, a high frequency signal is input to the second port 12, and this high frequency signal is output from the first port 11. From the fourth port 14, a combined signal having power corresponding to the power of the high-frequency signal input to the second port 12 is output.

  In the second usage mode, a ninth signal path passing through the second coupling unit 40B is provided between the second port 12 serving as an input port and the fourth port 14 serving as a coupling port. A tenth signal path passing through the coupling unit 40D and the second matching unit 30B, and an eleventh signal path passing through the third coupling unit 40C, the third matching unit 30C, and the second matching unit 30B; A twelfth signal path passing through the first coupling portion 40A, the first matching portion 30A, the third matching portion 30C, and the second matching portion 30B is formed. When a high-frequency signal is input to the second port 12, the combined signal output from the fourth port 14 is a signal obtained by synthesizing signals that have passed through the ninth to twelfth signal paths. The degree of coupling of the directional coupler 1 in the second usage mode is that the coupling strengths of the first to fourth coupling portions 40A, 40B, 40C, and 40D and the ninth to twelfth signal paths respectively pass. Depending on the phase relationship of the signal.

  In the second usage mode, a thirteenth signal path passing through the second coupling unit 40B and the fourth port 14 between the first port 11 serving as an output port and the fourth port 14 serving as a coupling port, A fourteenth signal path passing through the coupling unit 40D and the second matching unit 30B, and a fifteenth signal path passing through the third coupling unit 40C, the third matching unit 30C, and the second matching unit 30B; A sixteenth signal path that passes through the first coupling portion 40A, the first matching portion 30A, the third matching portion 30C, and the second matching portion 30B is formed. The isolation of the directional coupler 1 in the second usage mode passes through the coupling strengths of the first to fourth coupling portions 40A, 40B, 40C, and 40D and the thirteenth to sixteenth signal paths, respectively. Depending on the phase relationship of the signal.

  Here, a usage example of the directional coupler 1 when used in the first and second usage modes will be described with reference to FIG. 2. FIG. 2 is a circuit diagram showing an example of use of the directional coupler 1. FIG. 2 shows a transmission system circuit including the directional coupler 1. In addition to the directional coupler 1, the transmission system circuit shown in FIG. 2 includes a power amplifier 2, an automatic output control circuit (hereinafter referred to as an APC circuit) 3, and an impedance matching element 5.

  The power amplifier 2 has an input end, an output end, and a gain control end. A transmission signal, which is a high-frequency signal, is input to the input terminal of the power amplifier 2. The output terminal of the power amplifier 2 is connected to the first port 11 of the directional coupler 1.

  The APC circuit 3 has an input end and an output end. The input end of the APC circuit 3 is connected to the third port 13 of the directional coupler 1. The output end of the APC circuit 3 is connected to the gain control end of the power amplifier 2.

  The second port 12 of the directional coupler 1 is connected to the antenna 4 via the impedance matching element 5. The impedance matching element 5 is an element that performs impedance matching between the transmission system circuit and the antenna 4 in order to sufficiently reduce the level of the reflected wave signal generated when the transmission signal is reflected by the antenna 4. The fourth port 14 of the directional coupler 1 is grounded via a termination resistor 15.

  Next, a first usage mode of the directional coupler 1 in the transmission system circuit shown in FIG. 2 will be described. In the first usage mode, the transmission signal amplified by the power amplifier 2 is input to the first port 11 and output from the second port 12, and from the third port 13 to the first port 11. A combined signal having power corresponding to the power of the input transmission signal is output. The transmission signal output from the second port 12 is transmitted from the antenna 4 via the impedance matching element 5. The combined signal output from the third port 13 is input to the APC circuit 3. The APC circuit 3 controls the gain of the power amplifier 2 so that the level of the output signal of the power amplifier 2 becomes substantially constant according to the level of the combined signal output from the third port 13.

  Next, a second usage mode of the directional coupler 1 in the transmission system circuit shown in FIG. 2 will be described. The directional coupler 1 in the second usage mode is used to detect the level of a reflected wave signal generated by the transmission signal reflected by the antenna 4. In the second usage mode, the reflected wave signal is a high-frequency signal input to the directional coupler 1. The reflected wave signal is input to the second port 12 and output from the first port 11. Therefore, in the second usage mode, the second port 12 is an input port, the first port 11 is an output port, the fourth port 14 is a coupling port, and the third port 13 is a termination port. In the second usage mode, the third port 13 is grounded via a termination resistor. A power detector (not shown) is connected to the fourth port 14. The fourth port 14 outputs a combined signal having power corresponding to the power of the reflected wave signal input to the second port 12. Then, the level of this combined signal is detected by a power detector (not shown). Information on the level of the combined signal is used to adjust the characteristics of the impedance matching element 5 so that the level of the reflected wave signal becomes sufficiently small.

  The level of the reflected wave signal input to the directional coupler 1 is smaller than the level of the transmission signal input to the directional coupler 1. Therefore, the directional coupler 1 used in the first and second usage modes needs to have a sufficiently large isolation not only in the first usage mode but also in the second usage mode. .

  As described above, the directional coupler 1 according to the present embodiment has a circuit configuration that is symmetrical or nearly symmetric with respect to the third matching unit 30C, and as a result, has bidirectionality. . Therefore, the directional coupler 1 can be used in the first and second usage modes, and the same characteristics can be obtained in the first and second usage modes.

  Next, an example of the structure of the directional coupler 1 will be described. FIG. 3 is a perspective view of the directional coupler 1. The directional coupler 1 shown in FIG. 3 includes first to fourth ports 11 to 14, a main line 10, first to fourth sub line portions 20A, 20B, 20C, and 20D, and first to third ports. A laminated body 50 for integrating the matching portions 30A, 30B, and 30C is provided. As will be described in detail later, the multilayer body 50 includes a plurality of laminated dielectric layers and a plurality of conductor layers. Each of the inductors L1A and L1B is configured using one or more conductor layers of the plurality of conductor layers of the multilayer body 50. In addition, each of the inductors L2A and L2B is configured using a plurality of through holes formed in a plurality of dielectric layers of the multilayer body 50. Each of the capacitors C1A, C2A, C1B, and C2B is configured using two or more conductor layers among the plurality of conductor layers.

  The laminated body 50 has a rectangular parallelepiped shape having an outer peripheral portion. The outer peripheral portion of the stacked body 50 includes an upper surface 50A, a bottom surface 50B, and four side surfaces 50C to 50F. The upper surface 50A and the bottom surface 50B face opposite sides, the side surfaces 50C and 50D also face opposite sides, and the side surfaces 50E and 50F also face opposite sides. The side surfaces 50C to 50F are perpendicular to the upper surface 50A and the bottom surface 50B. In the multilayer body 50, the direction perpendicular to the top surface 50A and the bottom surface 50B is the stacking direction of the plurality of dielectric layers and the plurality of conductor layers. In FIG. 3, this stacking direction is indicated by an arrow with a symbol T.

  The directional coupler 1 shown in FIG. 3 includes a first terminal 111, a second terminal 112, a third terminal 113, a fourth terminal 114, and two ground terminals 115 and 116. Yes. The first to fourth terminals 111, 112, 113, and 114 correspond to the first to fourth ports 11, 12, 13, and 14 shown in FIG. The ground terminals 115 and 116 are connected to the ground. The terminals 111 to 116 are disposed on the bottom surface 50 </ b> B of the stacked body 50.

  Next, the stacked body 50 will be described in detail with reference to FIGS. 4 to 11. The stacked body 50 has 23 dielectric layers stacked. Hereinafter, the 23 dielectric layers are referred to as the first to 23rd dielectric layers in order from the bottom. FIG. 4 is a perspective view showing the inside of the laminated body 50. FIG. 5 is a cross-sectional view of the stacked body 50. 6A to 6D show pattern formation surfaces of the first to fourth dielectric layers, respectively. 7A to 7D show the pattern formation surfaces of the fifth to eighth dielectric layers, respectively. 8A to 8D show pattern formation surfaces of the ninth to twelfth dielectric layers, respectively. In FIG. 9, (a) to (d) show the pattern formation surfaces of the thirteenth to sixteenth dielectric layers, respectively. In FIG. 10, (a) to (d) show the pattern formation surfaces of the 17th to 20th dielectric layers, respectively. 11A to 11C show the top surfaces of the 21st to 23rd dielectric layers, respectively.

  As shown in FIG. 6A, the first to fourth terminals 111, 112, 113, 114 and the ground terminals 115, 116 are formed on the pattern forming surface of the first dielectric layer 51. Has been. The dielectric layer 51 has through holes 51T1, 51T2, 51T3, 51T4, 51T5, and 51T6 connected to the terminals 111, 112, 113, 114, 115, and 116, respectively.

  As shown in FIG. 6B, a ground conductor layer 521 is formed on the pattern forming surface of the second dielectric layer 52. The dielectric layer 52 has through holes 52T1, 52T2, 52T3, 52T4, 52T5, 52T6, 52T13, 52T14, 52T15, 52T16, 52T17, 52T18, and 52T19. The through holes 51T1 to 51T4 shown in FIG. 6A are connected to the through holes 52T1 to 52T4, respectively. The through holes 52T5, 52T6, 52T13 to 52T19 and the through holes 51T5 and 51T6 shown in FIG. 6A are connected to the conductor layer 521.

  As shown in FIG. 6C, a ground conductor layer 531 is formed on the pattern formation surface of the third dielectric layer 53. The dielectric layer 53 has through holes 53T1, 53T2, 53T3, 53T4, 53T13, 53T14, and 53T15. The through holes 52T1 to 52T4 shown in FIG. 6B are connected to the through holes 53T1 to 53T4, respectively. The through holes 53T13 to 53T15 and the through holes 52T5, 52T6, and 52T13 to 52T19 shown in FIG. 6B are connected to the conductor layer 531.

  As shown in FIG. 6D, the fourth dielectric layer 54 has through holes 54T1, 54T2, 54T3, 54T4, 54T13, 54T14, and 54T15. The through holes 53T1 to 53T4 and 53T13 to 53T15 shown in FIG. 6C are connected to the through holes 54T1 to 54T4 and 54T13 to 54T15, respectively.

  As shown in FIG. 7A, on the pattern formation surface of the fifth dielectric layer 55, the conductor layer 551 used for constituting the first subline portion 20A and the second subline A conductor layer 552 used to configure the portion 20B is formed. Each of the conductor layers 551 and 552 has a first end and a second end. The dielectric layer 55 has through holes 55T1, 55T2, 55T3, 55T4, 55T13, 55T14, and 55T15. The through holes 55T1, 55T2, and 55T13 to 55T15 are connected to the through holes 54T1, 54T2, and 54T13 to 54T15 shown in FIG. 6D, respectively. The through hole 55T3 is connected to the vicinity of the first end of the conductor layer 551. The through hole 55T4 is connected to the vicinity of the first end of the conductor layer 552. The through hole 54T3 shown in FIG. 6D is connected to the vicinity of the second end of the conductor layer 551. The through hole 54T4 shown in FIG. 6D is connected to the vicinity of the second end of the conductor layer 552.

  As shown in FIG. 7B, the sixth dielectric layer 56 has through holes 56T1, 56T2, 56T3, 56T4, 56T13, 56T14, and 56T15. The through holes 55T1 to 55T4 and 55T13 to 55T15 shown in FIG. 7A are connected to the through holes 56T1 to 56T4 and 56T13 to 56T15, respectively.

  As shown in FIG. 7C, the seventh dielectric layer 57 has through holes 57T1, 57T2, 57T3, 57T4, 57T13, 57T14, and 57T15. The through holes 56T1 to 56T4 and 56T13 to 56T15 shown in FIG. 7B are connected to the through holes 57T1 to 57T4 and 57T13 to 57T15, respectively.

  As shown in FIG. 7D, a conductor layer 581 used for configuring the main line 10 is formed on the pattern forming surface of the eighth dielectric layer 58. The conductor layer 581 has a first end and a second end. The dielectric layer 58 has through holes 58T3, 58T4, 58T13, 58T14, and 58T15. Through holes 57T3, 57T4, 57T13 to 57T15 shown in FIG. 7C are connected to the through holes 58T3, 58T4, 58T13 to 58T15, respectively. The through hole 57T1 shown in FIG. 7C is connected to a portion of the conductor layer 581 near the first end. The through hole 57T2 shown in FIG. 7C is connected to the vicinity of the second end of the conductor layer 581.

  As shown in FIG. 8A, the ninth dielectric layer 59 has through holes 59T3, 59T4, 59T13, 59T14, and 59T15. The through holes 58T3, 58T4, and 58T13 to 58T15 shown in FIG. 7D are connected to the through holes 59T3, 59T4, and 59T13 to 59T15, respectively.

  As shown in FIG. 8B, the tenth dielectric layer 60 has through holes 60T3, 60T4, 60T13, 60T14, and 60T15. The through holes 59T3, 59T4, 59T13 to 59T15 shown in FIG. 8A are connected to the through holes 60T3, 60T4, 60T13 to 60T15, respectively.

  As shown in FIG. 8C, on the pattern formation surface of the eleventh dielectric layer 61, the conductor layer 611 used to form the third subline portion 20C, and the fourth subline A conductor layer 612 used to configure the portion 20D is formed. Each of the conductor layers 611 and 612 has a first end and a second end. The dielectric layer 61 has through holes 61T3, 61T4, 61T7, 61T8, 61T9, 61T10, 61T13, 61T14, and 61T15. The through holes 60T3, 60T4, and 60T13 to 60T15 shown in FIG. 8B are connected to the through holes 61T3, 61T4, and 61T13 to 61T15, respectively. The through hole 61T7 is connected to the vicinity of the first end of the conductor layer 611. The through hole 61T8 is connected to the vicinity of the first end of the conductor layer 612. The through hole 61T9 is connected to the vicinity of the second end of the conductor layer 611. The through hole 61T10 is connected to the vicinity of the second end of the conductor layer 612.

  As shown in FIG. 8D, the twelfth dielectric layer 62 has through holes 62T3, 62T4, 62T7, 62T8, 62T9, 62T10, 62T13, 62T14, and 62T15. The through holes 61T3, 61T4, 61T7 to 61T10, and 61T13 to 61T15 shown in FIG. 8C are connected to the through holes 62T3, 62T4, 62T7 to 62T10, and 62T13 to 62T15, respectively.

  As shown in FIG. 9A, the thirteenth dielectric layer 63 has through holes 63T3, 63T4, 63T7, 63T8, 63T9, 63T10, 63T13, 63T14, and 63T15. The through holes 63T3, 63T4, 63T7 to 63T10, and 63T13 to 63T15 are connected to the through holes 62T3, 62T4, 62T7 to 62T10, and 62T13 to 62T15 shown in FIG. 8D, respectively.

  As shown in FIG. 9B, a ground conductor layer 641 and conductor layers 642 and 643 are formed on the pattern formation surface of the fourteenth dielectric layer 64. Each of the conductor layers 642 and 643 has a first end and a second end. The dielectric layer 64 has through holes 64T3, 64T4, 64T7, 64T8, 64T9, 64T10, a through hole 64T11 used to form the inductor L2A, and a through hole 64T12 used to form the inductor L2B. And are formed. The through holes 63T3, 63T4, 63T7, and 63T8 shown in FIG. 9A are connected to the through holes 64T3, 64T4, 64T7, and 64T8, respectively. The through hole 64T9 is connected to the vicinity of the first end of the conductor layer 642. The through hole 64T10 is connected to the vicinity of the first end of the conductor layer 643. The through holes 64T11 and 64T12 and the through holes 63T13 to 63T15 illustrated in FIG. 9A are connected to the conductor layer 641. The through hole 63T9 shown in FIG. 9A is connected to the vicinity of the second end of the conductor layer 642. The through hole 63T10 shown in FIG. 9A is connected to the vicinity of the second end of the conductor layer 643.

  As shown in FIG. 9C, the fifteenth dielectric layer 65 has through holes 65T3, 65T4, 65T7, 65T8, 65T9, 65T10, and a through hole 65T11 used to form the inductor L2A. The through-hole 65T12 used to configure the inductor L2B is formed. The through holes 65T3, 65T4, 65T7 to 65T12 are connected to the through holes 64T3, 64T4, 64T7 to 64T12 shown in FIG. 9B, respectively.

  As shown in FIG. 9D, on the pattern formation surface of the 16th dielectric layer 66, a conductor layer 661 used to configure the capacitor C2A and a conductor used to configure the capacitor C2B. Layer 662 is formed. The dielectric layer 66 has through holes 66T3, 66T4, 66T7, 66T8, 66T9, 66T10, a through hole 66T11 used to form the inductor L2A, and a through hole 66T12 used to form the inductor L2B. And are formed. The through holes 66T3, 66T4, 66T9 to 66T12 are connected to the through holes 65T3, 65T4, 65T9 to 65T12 shown in FIG. 9C, respectively. The through hole 66T7 is connected to the conductor layer 661 and the through hole 65T7 shown in FIG. The through hole 66T8 is connected to the conductor layer 662 and the through hole 65T8 shown in FIG.

  As shown in FIG. 10A, on the pattern forming surface of the 17th dielectric layer 67, the conductor layer 671 used to configure the capacitors C1A and C2A and the capacitors C1B and C2B are configured. And a conductor layer 672 used in the above. The dielectric layer 67 has through holes 67T3, 67T4, 67T7, 67T8, 67T9, and 67T10. The through holes 66T3, 66T4, 66T7 to 66T10 shown in FIG. 9D are connected to the through holes 67T3, 67T4, 67T7 to 67T10, respectively. The through hole 66T11 shown in FIG. 9D is connected to the conductor layer 671. The through hole 66T12 illustrated in FIG. 9D is connected to the conductor layer 672.

  As shown in FIG. 10B, on the pattern formation surface of the 18th dielectric layer 68, a conductor layer 681 used for constituting the capacitor C1A and a conductor used for constituting the capacitor C1B. Layer 682 is formed. The dielectric layer 68 has through holes 68T3, 68T4, 68T7, 68T8, 68T9, and 68T10. The through hole 68T3 and the through hole 67T3 shown in FIG. 10A are connected to the conductor layer 681. The through hole 68T4 and the through hole 67T4 shown in FIG. 10A are connected to the conductor layer 682. The through holes 67T7 to 67T10 shown in FIG. 10A are connected to the through holes 68T7 to 68T10, respectively.

  As shown in FIG. 10C, the nineteenth dielectric layer 69 has through holes 69T3, 69T4, 69T7, 69T8, 69T9, and 69T10. The through holes 68T3, 68T4, 68T7 to 68T10 shown in FIG. 10B are connected to the through holes 69T3, 69T4, 69T7 to 69T10, respectively.

  As shown in FIG. 10D, the 20th dielectric layer 70 has through holes 70T3, 70T4, 70T7, 70T8, 70T9, and 70T1. The through holes 69T3, 69T4, and 69T7 to 69T10 shown in FIG. 10C are connected to the through holes 70T3, 70T4, and 70T7 to 70T10, respectively.

  As shown in FIG. 11A, the 21st dielectric layer 71 has through holes 71T3, 71T4, 71T7, 71T8, 71T9, and 71T10. The through holes 70T3, 70T4, and 70T7 to 70T10 shown in FIG. 10D are connected to the through holes 71T3, 71T4, and 71T7 to 71T10, respectively.

  As shown in FIG. 11B, on the pattern formation surface of the twenty-second dielectric layer 72, a conductor layer 721 used to configure the inductor L1A and a conductor used to configure the inductor L1B. A layer 722 and a conductor layer 723 used to form the third matching portion 30C are formed. Each of the conductor layers 721 to 723 has a first end and a second end. The through hole 71T3 illustrated in FIG. 11A is connected to the vicinity of the first end of the conductor layer 721. The through hole 71T4 shown in FIG. 11A is connected to the vicinity of the first end of the conductor layer 722. The through hole 71T7 shown in FIG. 11A is connected to the vicinity of the second end of the conductor layer 721. The through hole 71T8 shown in FIG. 11A is connected to the vicinity of the second end of the conductor layer 722. The through hole 71T9 shown in FIG. 11A is connected to the vicinity of the first end of the conductor layer 723. The through hole 71T10 shown in FIG. 11A is connected to the vicinity of the second end of the conductor layer 723.

  As shown in FIG. 11C, a mark 731 is formed on the pattern forming surface of the 23rd dielectric layer 73.

  In the laminated body 50 shown in FIG. 3, the first to 23rd dielectric layers 51 to 73 are laminated so that the element formation surface of the first dielectric layer 51 is the bottom surface 50B of the laminated body 50. Configured.

  FIG. 4 shows the inside of the stacked body 50. FIG. 5 shows a cross section of the laminate 50 as viewed from the side surface 50D.

  Hereinafter, the correspondence between the circuit components of the directional coupler 1 shown in FIG. 1 and the internal components of the laminate 50 shown in FIGS. 6 to 11 will be described. The main line 10 is constituted by the conductor layer 581 shown in FIG. The conductor layer 581 has a first surface facing the same direction as the element formation surface of the dielectric layer 58, and a second surface opposite to the first surface. The first surface of the conductor layer 581 includes a first portion and a second portion. The second surface of the conductor layer 581 includes a third portion and a fourth portion.

  A part of the conductor layer 551 shown in FIG. 7A is opposed to the first portion of the first surface of the conductor layer 581 with the dielectric layers 55 to 57 interposed therebetween. A part of the conductor layer 552 shown in FIG. 7A is opposed to the second portion of the first surface of the conductor layer 581 with the dielectric layers 55 to 57 interposed therebetween. The first sub line portion 20A is constituted by a part of the conductor layer 551. The second sub line portion 20 </ b> B is configured by a part of the conductor layer 552.

  A part of the conductor layer 611 shown in FIG. 8C is opposed to the third portion of the second surface of the conductor layer 581 with the dielectric layers 58 to 60 interposed therebetween. A part of the conductor layer 612 shown in FIG. 8C is opposed to the third portion of the second surface of the conductor layer 581 with the dielectric layers 58 to 60 interposed therebetween. The third sub line portion 20 </ b> C is configured by a part of the conductor layer 611. The fourth sub line portion 20 </ b> D is configured by a part of the conductor layer 612.

  The inductor L1A of the first matching unit 30A is configured by the conductor layer 721 shown in FIG. In the vicinity of the first end of the conductor layer 721, the through holes 55T3, 56T3, 57T3, 58T3, 59T3, 60T3, 61T3, 62T3, 63T3, 64T3, 65T3, 66T3, 67T3, the conductor layer 681 and the through holes 68T3, 69T3 It is connected to the conductor layer 551 constituting the first sub line portion 20A via 70T3 and 71T3. In the vicinity of the second end of the conductor layer 721, the conductor constituting the third sub-line portion 20C via the through holes 61T7, 62T7, 63T7, 64T7, 65T7, 66T7, 67T7, 68T7, 69T7, 70T7, 71T7. Connected to the layer 611.

  The capacitor C1A of the first matching unit 30A is configured by the conductor layers 671 and 681 shown in FIGS. 10A and 10B and the dielectric layer 67 between the conductor layers 671 and 681. The conductor layer 681 is formed on the conductor layer 551 constituting the first sub line portion 20A through the through holes 55T3, 56T3, 57T3, 58T3, 59T3, 60T3, 61T3, 62T3, 63T3, 64T3, 65T3, 66T3, 67T3. It is connected.

  The capacitor C2A of the first matching unit 30A is configured by the conductor layers 661 and 671 shown in FIGS. 9D and 10A and the dielectric layer 66 between the conductor layers 661 and 671. . The conductor layer 661 is connected to the conductor layer 611 constituting the third subline portion 20C through the through holes 61T7, 62T7, 63T7, 64T7, and 65T7.

  The inductor L2A of the first matching unit 30A is configured by through holes 64T11, 65T11, and 66T11 shown in FIGS. 9B to 9D. The through hole 66T11 is connected to the conductor layer 671 shown in FIG. The through hole 64T11 is connected to the ground conductor layer 641.

  The inductor L1B of the second matching unit 30B is configured by the conductor layer 722 shown in FIG. In the vicinity of the first end of the conductor layer 722, through holes 55T4, 56T4, 57T4, 58T4, 59T4, 60T4, 61T4, 62T4, 63T4, 64T4, 65T4, 66T4, 67T4, conductor layer 682 and through holes 68T4, 69T4 It is connected to the conductor layer 552 constituting the second sub line portion 20B via 70T4 and 71T4. In the vicinity of the second end of the conductor layer 722, the conductor constituting the fourth sub line portion 20D is formed through the through holes 61T8, 62T8, 63T8, 64T8, 65T8, 66T8, 67T8, 68T8, 69T8, 70T8, 71T8. Connected to layer 612.

  The capacitor C1B of the second matching unit 30B includes the conductor layers 672 and 682 shown in FIGS. 10A and 10B and the dielectric layer 67 between the conductor layers 672 and 682. The conductor layer 682 is formed on the conductor layer 552 constituting the second sub line portion 20B through the through holes 55T4, 56T4, 57T4, 58T4, 59T4, 60T4, 61T4, 62T4, 63T4, 64T4, 65T4, 66T4, 67T4. It is connected.

  The capacitor C2B of the second matching unit 30B is configured by the conductor layers 662 and 672 shown in FIGS. 9D and 10A and the dielectric layer 66 between the conductor layers 662 and 672. . The conductor layer 662 is connected to the conductor layer 612 constituting the fourth subline portion 20D through the through holes 61T8, 62T8, 63T8, 64T8, and 65T8.

  The inductor L2B of the second matching unit 30B is configured by the through holes 64T12, 65T12, and 66T12 shown in FIGS. The through hole 66T12 is connected to the conductor layer 672 shown in FIG. The through hole 64T12 is connected to the ground conductor layer 641.

  The third matching portion 30C is configured by the conductor layer 723 shown in FIG. In the vicinity of the first end of the conductor layer 723, the third sub-line is formed through the through holes 61T9, 62T9, 63T9, the conductor layer 642 and the through holes 64T9, 65T9, 66T9, 67T9, 68T9, 69T9, 70T9, 71T9. The conductor layer 611 constituting the part 20C is connected. In the vicinity of the second end of the conductor layer 723, through-holes 61T10, 62T10, 63T10, the conductor layer 643 and the through-holes 64T10, 65T10, 66T10, 67T10, 68T10, 69T10, 70T10, 71T10 The conductor layer 612 constituting the portion 20D is connected.

  In the multilayer body 50, a ground conductor layer connected to the ground is provided between the plurality of conductor layers constituting the first to third matching portions 30A, 30B, and 30C and the conductor layer 681 constituting the main line 10. 641 is interposed. Therefore, the first to third matching portions 30A, 30B, and 30C are not electromagnetically coupled to the main line 10.

  The ground conductor layer 531 shown in FIG. 6C has an effect of adjusting the impedance of the first and second sub-line portions 20A and 20B to a desired value. The ground conductor layer 641 shown in FIG. 9B has an effect of adjusting the impedance of the third and fourth sub-line portions 20C and 20D to a desired value.

  According to the directional coupler 1 according to the present embodiment, in a wider frequency band than in the directional coupler having a configuration in which the number of sub-line portions electromagnetically coupled to the main line is three or less, the frequency It becomes possible to suppress the change in the degree of coupling accompanying the change in. This will be described in detail below.

  Of the directional coupler 1, the portion composed of the third coupling portion 40C, the fourth coupling portion 40D, and the third matching portion 30C constitutes a directional coupler composed of two coupling portions and one matching portion. I can say that. In the following description, a portion including the third coupling portion 40C, the fourth coupling portion 40D, and the third matching portion 30C is referred to as a coupler portion. The directional coupler 1 can be roughly divided into a coupler portion, first and second coupling portions 40A and 40B, and first and second matching portions 30A and 30B. Hereinafter, these characteristics will be described.

  FIG. 12 shows the frequency characteristics of the single coupling degree of each of the first and second coupling portions 40A and 40B. In FIG. 12, the horizontal axis represents frequency and the vertical axis represents the degree of coupling. As shown in FIG. 12, the single coupling degree of each of the first and second coupling portions 40A and 40B increases as the frequency increases. Although not shown, the single coupling degree of each of the third and fourth coupling units 40C and 40D also increases as the frequency increases. The single coupling degree of each of the third and fourth coupling portions 40C and 40D is larger than the single coupling degree of each of the first and second coupling portions 40A and 40B. At a frequency of 2000 MHz, the single coupling degree of each of the third and fourth coupling portions 40C and 40D may be 5 dB or more larger than the single coupling degree of each of the first and second coupling portions 40A and 40B. preferable.

  Here, the amount of phase change caused by each of matching units 30A, 30B, and 30C with respect to a signal passing therethrough is referred to as a phase change amount. Since the matching units 30A, 30B, and 30C all delay the phase of the signal passing therethrough, the phase change amount is represented by a negative value. In each of the matching units 30A, 30B, and 30C, it can be said that the larger the absolute value of the phase change amount, the larger the phase change that occurs with respect to the signal passing therethrough.

  FIG. 13 shows frequency characteristics of the phase change amounts of the first and second matching units 30A and 30B. FIG. 14 shows the frequency characteristics of the phase change amount of the third matching unit 30C. 13 and 14, the horizontal axis represents frequency, and the vertical axis represents phase change amount. As shown in FIGS. 13 and 14, the third matching unit 30 </ b> C has a smaller phase change to be generated with respect to signals of the same frequency than the first and second matching units 30 </ b> A and 30 </ b> B. In other words, the third matching unit 30C has a higher frequency at which the absolute value of the phase change amount is 180 degrees than the first and second matching units 30A and 30B. In the example shown in FIG. 13, the frequency at which the absolute value of the phase change amount of each of the first and second matching units 30A and 30B is 180 degrees is about 3800 MHz. In the example illustrated in FIG. 14, the frequency at which the absolute value of the phase change amount of the third matching unit 30C is 180 degrees exceeds 5000 MHz. At a frequency of 2000 MHz, the difference between the absolute value of the phase change amount of each of the first and second matching units 30A and 30B and the absolute value of the phase change amount of the third matching unit 30C may be 10 degrees or more. preferable.

  FIG. 15 shows the above-described coupler portion including the third coupling portion 40C, the fourth coupling portion 40D, and the third matching portion 30C. In the first usage mode, in the coupler portion, between the first port 11 serving as an input port and the first end portion 20C1 of the third sub-line portion 20C serving as a coupling port in the coupler portion, A signal path passing through the third coupling unit 40C and a signal path passing through the fourth coupling unit 40D and the third matching unit 30C are formed.

  FIG. 16 shows the frequency characteristics of the degree of coupling of the coupler portion shown in FIG. In FIG. 16, the horizontal axis represents frequency and the vertical axis represents the degree of coupling. As shown in FIG. 16, the degree of coupling of the coupler portion increases as the frequency increases up to about 3000 MHz, but decreases as the frequency increases in the range from about 3000 MHz to 5000 MHz. In the frequency range shown on the horizontal axis of FIG. 16, the higher the frequency, the greater the degree of coupling of each of the third and fourth coupling portions 40C and 40D, but the third matching portion 30C. This is because the absolute value of the phase change amount approaches 180 degrees. As the absolute value of the phase change amount of the third matching unit 30C approaches 180 degrees, the signal that has passed through the signal path passing through the third coupling unit 40C, the fourth coupling unit 40D, and the third matching unit 30C. The degree of cancellation of the signals that have passed through the signal path passing through is increased. In this way, a change in the coupling degree of the coupler portion accompanying a change in frequency is suppressed.

  Here, in order to compare with the coupler portion shown in FIG. 15, the coupling portion having the configuration shown in FIG. 17 is considered. This coupling portion has a configuration in which the third sub-line portion 20C and the fourth sub-line portion 20D are connected except for the third matching portion 30C from the coupler portion shown in FIG. In this coupling portion, no phase change occurs between the third subline portion 20C and the fourth subline portion 20D. Therefore, in this coupling portion, the combination of the third sub line portion 20C and the fourth sub line portion 20D can be regarded as one sub line portion. Therefore, this coupling portion can be regarded as a portion where the central sub-line portion and the main line portion are coupled to each other in a directional coupler having three sub-line portions as described in Patent Document 2. . Hereinafter, the joint portion shown in FIG. 17 is referred to as a central joint portion of the comparative example.

  FIG. 18 shows the frequency characteristics of the coupling degree of the central coupling portion of the comparative example shown in FIG. In FIG. 18, the horizontal axis represents frequency and the vertical axis represents the degree of coupling. As shown in FIG. 18, the degree of coupling of the central coupling portion of the comparative example increases as the frequency increases in the frequency range shown on the horizontal axis of FIG.

  Here, a directional coupler having a configuration in which the coupler portion in the directional coupler 1 is replaced with the central coupling portion of the comparative example shown in FIG. 17 is referred to as a directional coupler of the comparative example. The directional coupler of the comparative example can be regarded as a directional coupler in which the number of sub-line portions is 3 and the number of matching portions is 2. In the directional coupler of the comparative example, the single coupling degree of the central coupling portion is larger than the single coupling degrees of the first and second coupling portions 40A and 40B.

  FIG. 19 shows frequency characteristics of the degree of coupling of the directional coupler of the comparative example. In FIG. 19, the horizontal axis represents frequency and the vertical axis represents the degree of coupling.

  20 to 22 show examples of characteristics of the directional coupler 1 according to the present embodiment. In the example shown in FIGS. 20 to 22, the use frequency band of the directional coupler 1 is set to 673 to 3800 MHz. 19 and 20, the lower limit and the upper limit of this use frequency band are indicated by two dotted lines. The characteristics shown in FIGS. 20 to 22 are obtained by simulation. 20 to 22 show the characteristics of the directional coupler 1 when used in the first usage mode. In the simulation, the characteristics of the directional coupler 1 when used in the second usage mode are the same as the characteristics of the directional coupler 1 when used in the first usage mode.

  FIG. 20 shows frequency characteristics of the degree of coupling of the directional coupler 1. In FIG. 20, the horizontal axis represents frequency and the vertical axis represents the degree of coupling. When the degree of coupling is represented as -c (dB), in the directional coupler 1, the value of c is 20 or more in the use frequency band.

  FIG. 21 shows the frequency characteristics of isolation of the directional coupler 1. In FIG. 21, the horizontal axis represents frequency and the vertical axis represents isolation. When the isolation is expressed as -i (dB), in the directional coupler 1, the value of i is a sufficient value of 45 or more in the used frequency band.

  FIG. 22 shows the frequency characteristic of the reflection loss of the coupling port of the directional coupler 1. In FIG. 22, the horizontal axis represents the frequency, and the vertical axis represents the reflection loss of the coupling port. When the reflection loss of the coupling port is expressed as −r (dB), in the directional coupler 1, the value of r is a sufficient value of 20 or more in the used frequency band. This means that in the operating frequency band, the absolute value of the reflection coefficient when viewing the other side from one of the third port 13 and the fourth port 14 is 0 or a value in the vicinity thereof. Yes.

  Here, the frequency characteristic of the degree of coupling of the directional coupler of the comparative example shown in FIG. 19 is compared with the frequency characteristic of the degree of coupling of the directional coupler 1 shown in FIG. In the directional coupler of the comparative example, the difference between the maximum value and the minimum value of the coupling degree is about 10 dB in the frequency band of 673 to 3800 MHz. On the other hand, in the directional coupler 1, the difference between the maximum value and the minimum value of the coupling degree is about 5 dB in the frequency band of 673 to 3800 MHz. The frequency range in which the difference between the maximum value and the minimum value of the coupling degree in the directional coupler of the comparative example is about 5 dB is the frequency range in which the difference between the maximum value and the minimum value in the directional coupler 1 is about 5 dB. Narrower than.

  As can be seen from a comparison between FIG. 19 and FIG. 20, the directional coupler 1 suppresses a change in the degree of coupling accompanying a change in frequency in a wider frequency range than the directional coupler of the comparative example. be able to. In a directional coupler having a configuration in which the number of sub-line portions is 2 or less, a change in the degree of coupling accompanying a change in frequency is suppressed more than in a directional coupler having a configuration in which the number of sub-line portions is 3. It is difficult. From the above, according to the directional coupler 1 according to the present embodiment, the frequency change occurs in a wider frequency range as compared with the directional coupler having a configuration in which the number of sub-line portions is three or less. A change in the degree of coupling can be suppressed.

  Hereinafter, according to the directional coupler 1 according to the present embodiment, compared to the directional coupler of the comparative example, in the wider frequency range, the reason why the change in the degree of coupling accompanying the change in frequency can be suppressed is a concept. I will explain it.

  First, the nature of the frequency characteristics of the degree of coupling of the directional coupler of the comparative example will be conceptually described. In the directional coupler of the comparative example, as described above, the single coupling degree of the central coupling portion is larger than the single coupling degrees of the first and second coupling portions 40A and 40B. Therefore, the frequency characteristic of the degree of coupling of the directional coupler of the comparative example greatly depends on the frequency characteristic of the degree of coupling of the central coupling portion shown in FIG.

  In the directional coupler of the comparative example, with respect to the signal that has passed through the central coupling portion, the signal that has passed through the first coupling portion 40A and the signal that has passed through the second coupling portion 40B are respectively the first matching portion 30A. Are combined under the phase relationship determined by the second matching unit 30B to form a combined signal. As the absolute value of the phase change amount of each of the first and second matching units 30A and 30B approaches 180 degrees, the signal passing through the first coupling unit 40A and the signal passing through the second coupling unit 40B are The degree of cancellation of the signal that has passed through the central coupling portion is increased. As a result, the frequency characteristic of the degree of coupling of the directional coupler of the comparative example suppresses the change in the degree of coupling accompanying the change in frequency compared to the frequency characteristic of the degree of coupling of the central coupling portion shown in FIG. Will be.

  However, in the directional coupler of the comparative example, when the frequency exceeds the frequency at which the absolute value of the phase change amount of each of the first and second matching units 30A and 30B exceeds 180 degrees, the higher the frequency, the higher the center. The coupling degree of each of the coupling portion, the first coupling portion 40A, and the second coupling portion 40B is increased, and the signal that has passed through the first coupling portion 40A and the signal that has passed through the second coupling portion 40B are centered. The degree of cancellation of the signal that has passed through the coupling portion is reduced. As a result, in the directional coupler of the comparative example, when the frequency exceeds the frequency at which the absolute value of the phase change amount of each of the first and second matching units 30A and 30B exceeds 180 degrees, the higher the frequency, the higher the coupling. The degree is increased.

  Next, the nature of the frequency characteristic of the degree of coupling of the directional coupler 1 according to the present embodiment will be conceptually described. In the directional coupler 1, as described above, the single coupling degrees of the third and fourth coupling sections 40C and 40D are the single coupling degrees of the first and second coupling sections 40A and 40B. Bigger than. Therefore, the frequency characteristic of the coupling degree of the directional coupler 1 greatly depends on the frequency characteristic of the coupling degree of the coupler portion shown in FIG.

  In the directional coupler 1, the signal passing through the first coupling unit 40A and the signal passing through the second coupling unit 40B are compared with the first matching unit 30A and the first matching unit 30A with respect to the signal passing through the coupler unit, respectively. The combined signals are formed under the phase relationship determined by the two matching portions 30B. As the absolute value of the phase change amount of each of the first and second matching units 30A and 30B approaches 180 degrees, the signal passing through the first coupling unit 40A and the signal passing through the second coupling unit 40B are The degree of cancellation of the signal that has passed through the coupler portion increases. As a result, the frequency characteristic of the degree of coupling of the directional coupler 1 is suppressed from changing in the degree of coupling due to the change in frequency compared to the frequency characteristic of the degree of coupling of the coupler portion shown in FIG. It will be a thing.

  In addition, the third matching unit 30C has a higher frequency at which the absolute value of the phase change amount is 180 degrees than the first and second matching units 30A and 30B. Accordingly, as shown in FIG. 16, the frequency characteristics of the coupling degree of the coupler part exceed the frequency at which the absolute value of the phase change amount of each of the first and second matching units 30A and 30B is 180 degrees. In this frequency range, a characteristic in which a change in the degree of coupling accompanying a change in frequency is suppressed can be obtained. As a result, according to the directional coupler 1, the directivity of the comparative example is obtained in a frequency range in which the absolute value of the phase change amount of each of the first and second matching units 30A and 30B exceeds the frequency at which the absolute value is 180 degrees. Compared with a coupler, a change in the degree of coupling accompanying a change in frequency can be suppressed. Therefore, according to the directional coupler 1, a change in the degree of coupling accompanying a change in frequency can be suppressed in a wider frequency range as compared with the directional coupler of the comparative example.

  Further, as described above, the directional coupler 1 can have a circuit configuration that is symmetric or nearly symmetric. Thereby, the bidirectional directional coupler 1 can be realized.

  From the above, according to the present embodiment, it is possible to realize the directional coupler 1 that can be used in a wide band and has bidirectionality. The directional coupler 1 according to the present embodiment can be used for a plurality of signals in a plurality of frequency bands used in CA, for example.

  Further, in the present embodiment, the third matching unit 30C has a smaller phase change that is generated for signals having the same frequency than the first and second matching units 30A and 30B. Therefore, the third matching unit 30C can be easily configured with a relatively short line. Thereby, the configuration of the directional coupler 1 is made as compared with the case where the third matching unit 30C is configured using a plurality of inductors and a plurality of capacitors like the first and second matching units 30A and 30B. Can be simple.

  Note that the second inductor L2A in the first matching unit 30A and the second inductor L2B in the second matching unit 30B both have an inductance of 0.1 nH or more as described above. . In general, in a laminate including a plurality of laminated dielectric layers and a plurality of conductor layers and used for constituting an electronic component, the parasitic inductance of the conductor layer connected to the ground is 0.1 nH. Is less than. Therefore, the inductance of 0.1 nH or more included in the second inductors L2A and L2B is clearly distinguished from the parasitic inductance.

  In the present embodiment, the circuit configuration of the directional coupler 1 may be close to symmetry even if it is not completely symmetrical. Also in this case, the directional coupler 1 that can be used in a wide band and has bidirectionality can be realized. The requirements and preferable requirements necessary to satisfy the requirement that the circuit configuration of the directional coupler 1 is nearly symmetrical are specifically as follows, for example.

  The difference in the degree of coupling between the first coupling unit 40A and the second coupling unit 40B at a frequency of 2000 MHz needs to be 2 dB or less, and is preferably 1 dB or less. The difference in phase change between the first matching unit 30A and the second matching unit 30B at a frequency of 2000 MHz needs to be 20 degrees or less, preferably 10 degrees or less, and more preferably 5 degrees or less. preferable. Further, the difference in the degree of coupling between the third coupling unit 40C and the fourth coupling unit 40D at a frequency of 2000 MHz needs to be 2 dB or less, and is preferably 1 dB or less.

  In addition, this invention is not limited to the said embodiment, A various change is possible. For example, the configurations of the first to third matching portions in the present invention are not limited to those shown in the embodiment, and various modifications are possible on the assumption that the requirements described in the claims are satisfied. It is. For example, the third matching unit 30C may have the same configuration as the first and second matching units 30A and 30B except for the element constant. Alternatively, the first and second matching portions 30A and 30B may be lines like the third matching portion 30C.

  Further, the directional coupler of the present invention includes, in addition to the third matching portion, between the second end portion of the third sub line portion and the second end portion of the fourth sub line portion. One or more sets of additional sub-line portions and additional matching portions may be provided. In this case, between the second end portion of the third sub-line portion and the second end portion of the fourth sub-line portion, a matching portion is located at each end on the circuit configuration, and the matching portion and Two or more matching portions and one or more subline portions are provided in series so that the subline portions are alternately arranged. In this case, the third sub-line unit and the fourth sub-line unit, and two or more matching units and one or more sub-line units between them replace the coupler unit in the embodiment. A new coupler part can be constructed. And the frequency characteristic of the coupling degree of this new coupler part can be made into the characteristic by which the change of the coupling degree of the coupler part accompanying the change of a frequency was suppressed. Further, even when one or more sets of additional sub-line portions and additional matching portions are provided, the circuit configuration of the directional coupler can be made symmetric or nearly symmetric. Therefore, also in this case, the function and effect described in the embodiment can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Directional coupler, 10 ... Main line, 11 ... 1st port, 12 ... 2nd port, 13 ... 3rd port, 14 ... 4th port, 15 ... Terminating resistance, 20A ... 1st Sub line section, 20B ... second sub line section, 20C ... third sub line section, 20D ... fourth sub line section, 30A ... first matching section, 30B ... second matching section, 30C ... second. 3 matching sections.

Claims (5)

A first port;
A second port;
A third port;
A fourth port;
A main line connecting the first port and the second port;
A first sub-line portion, a second sub-line portion, a first sub-line portion, a first sub-line portion having a first end and a second end located on opposite sides of the main line and electromagnetically coupled to the main line, respectively, 3 subline sections and a fourth subline section;
A first matching section;
A second matching section;
A directional coupler comprising a third matching section,
A first end of the first sub-line portion is connected to the third port;
A first end of the second subline section is connected to the fourth port;
The first matching portion is provided between a second end portion of the first sub line portion and a first end portion of the third sub line portion,
The second matching portion is provided between a second end portion of the second subline portion and a first end portion of the fourth subline portion,
The third matching portion is provided between a second end portion of the third sub line portion and a second end portion of the fourth sub line portion,
Each of the first to third matching units causes a phase change with respect to a signal passing therethrough.   2. The directional coupler according to claim 1, wherein the third and fourth sub-line portions have higher coupling strength to the main line than the first and second sub-line portions. .   3. The directional coupling according to claim 1, wherein the third matching unit has a smaller phase change caused by a signal having the same frequency than the first and second matching units. vessel. Each of the first matching portion and the second matching portion connects a first path connecting the first end and the second end, and connecting the first path and the ground. A second path,
The first path includes a first inductor;
The second path includes a first capacitor and a second inductor connected in series,
The directional coupler according to claim 1, wherein the third matching unit is a line. The first inductor has a first end and a second end located on opposite sides;
The second inductor has a first end closest to the first path in circuit configuration, and a second end closest to ground in the circuit configuration;
The first capacitor is provided between a first end of the first inductor and a first end of the second inductor;
The second path further includes a second capacitor provided between a second end portion of the first inductor and a first end portion of the second inductor. The directional coupler according to claim 4.

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