Patent Publication Number: US-11664571-B2

Title: Coupler module

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation of International Application No. PCT/JP2019/049156 filed on Dec. 16, 2019 which claims priority from Japanese Patent Application No. 2018-235771 filed on Dec. 17, 2018. The contents of these applications are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     The present disclosure relates to a coupler module in which a directional coupler is mounted on a substrate. 
     Description of the Related Art 
     A directional coupler configured of a main line and a sub-line that are formed in a multilayer body has been known (for example, Patent Document 1). The directional coupler of Patent Document 1 is used while being mounted on a substrate. 
     Patent Document 1: International Publication No. 2012/017713 
     BRIEF SUMMARY OF THE DISCLOSURE 
     When a directional coupler is mounted on a substrate alone or with other elements to form a coupler module, an effective coupling degree of the directional coupler may vary due to the influence of a parasitic component of the substrate or the influence of the other elements. The variation in coupling degree may be a factor that impairs the accuracy of a detection signal outputted from the directional coupler. 
     Therefore, an object of the present disclosure is to provide a coupler module in which a directional coupler is mounted on a substrate and an effective coupling degree of the directional coupler can be easily adjusted. 
     In order to achieve the above object, a coupler module according to an aspect of the present disclosure includes a component formed with a main line and a sub-line that configure a directional coupler, and a substrate on which the component is mounted and on which a wiring coupled in series with the main line is formed, and at least a part of the wiring is along the main line in plan view of the substrate. 
     In addition, a coupler module according to an aspect of the present disclosure includes a component formed with a main line and a sub-line that configure a directional coupler, and a substrate on which the component is mounted and a wiring coupled in series with the main line is formed, and at least a part of the wiring overlaps with the sub-line in plan view of the substrate. 
     With this, a magnetic field obtained by synthesizing the magnetic fields generated by a main signal in or around a part of the wiring with the magnetic fields generated in or around the main line is caused to act on the sub-line, capacitive coupling is formed between the part of the wiring line and the sub-line, and thus, an effective coupling degree of the directional coupler can be adjusted. For example, in a case where the coupling degree is deviated when the directional coupler is mounted on the substrate, the coupling degree can be corrected by changing a wiring pattern of the substrate. Since the wiring pattern of the substrate can be changed in a region overlapping with the directional coupler in plan view of the substrate, the coupling degree can be adjusted without an increase in size of the coupler module. Further, since the substrate is modified, it is possible to adjust the coupling degree in a short period of time and at a low cost, compared to a case where the directional coupler itself is modified. As a result, the coupler module that facilitates the adjustment of the effective coupling degree of the directional coupler can be obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG.  1    is a functional block diagram illustrating an example of a configuration of a general coupler module. 
       Each of  FIGS.  2 A and  2 B  is a diagram illustrating an example of a basic structure of a coupler module. 
       Each of  FIGS.  3 A and  3 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 1. 
         FIG.  4    is a graph showing an example of a coupling degree of a coupler module having a basic structure. 
         FIG.  5    is a graph showing an example of a coupling degree of the coupler module according to Embodiment 1. 
       Each of  FIGS.  6 A and  6 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 2. 
         FIG.  7    is a graph showing an example of a coupling degree of the coupler module according to Embodiment 2. 
       Each of  FIGS.  8 A and  8 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 3. 
       Each of  FIGS.  9 A and  9 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 4. 
         FIG.  10    is a graph showing an example of a coupling degree of the coupler module according to Embodiment 4. 
       Each of  FIGS.  11 A and  11 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 5. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     A plurality of embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments to be described below all represent general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement and coupling forms of the constituent elements, and the like, which will be described in the following embodiments, are mere examples and are not intended to limit the present disclosure. 
     Embodiment 1 
     A coupler module according to Embodiment 1 will be described. 
       FIG.  1    is a functional block diagram illustrating an example of a general configuration of a coupler module. As illustrated in  FIG.  1   , the coupler module  1  includes a coupler component  10  and a module substrate  20 . 
     The coupler component  10  includes a directional coupler configured of a main line  11  and a sub-line  12 . 
     The module substrate  20  has an input port IN, an output port OUT, a first port P 1 , and a second port P 2 . 
     One end and the other end of the main line  11  are coupled to the input port IN and the output port OUT, respectively. One end and the other end of the sub-line  12  are coupled to the first port P 1  and the second port P 2 , respectively. 
     The main line  11  and the sub-line  12  are electromagnetically coupled to each other. Due to the electromagnetic coupling between the main line  11  and the sub-line  12 , a part of a power of a main signal flowing through the main line  11  in a direction from the input port IN toward the output port OUT (hereinafter referred to as a forward direction) is outputted from the first port P 1 . Further, a part of a power of a main signal flowing through the main line  11  in a direction from the output port OUT toward the input port IN (hereinafter referred to as a reverse direction) is outputted from the second port P 2 . The signals outputted from the first port P 1  and the second port P 2  are used as detection signals indicating the magnitudes of a main signal in the forward direction and a main signal in the reverse direction, respectively. 
     Note that a port, of the first port P 1  and the second port P 2 , that does not output a signal is terminated by using a termination circuit (not illustrated). Specifically, when the signal in the forward direction is outputted from the first port P 1 , the second port P 2  is terminated, and when the signal in the reverse direction is outputted from the second port P 2 , the first port P 1  is terminated. 
     In this specification, a power ratio of the detection signal to the main signal is referred to as coupling degree, and the coupling degree is quantitatively expressed as a negative decibel value. The coupling degree is individually defined for each of the main signal in the forward direction and the main signal in the reverse direction. Further, an end portion coupled to the input port IN of the main line  11  is referred to as an input end, and an end portion coupled to the output port OUT of the main line  11  is referred to as an output end. 
     Each of  FIGS.  2 A and  2 B  is a diagram illustrating an example of a basic structure of the coupler module  1 , and  FIG.  2 A  is a plan view and  FIG.  2 B  is a side view. As illustrated in  FIGS.  2 A and  2 B , the coupler module  1  is configured by mounting the coupler component  10  on the module substrate  20  as a basic structure. 
     The coupler component  10  includes the main line  11 , the sub-line  12 , via conductors  13  and  14 , and coupling electrodes  15  and  16  all of which are formed in or on a substrate  17 . One end and the other end of the main line  11  are coupled to the coupling electrodes  15  and  16  with the via conductors  13  and  14  interposed therebetween, respectively. One end and the other end of the sub-line  12  are also coupled to the coupling electrodes with the via conductors interposed therebetween (not illustrated). 
     The coupler component  10  may be, for example, an integrated circuit chip in which each portion is formed on the substrate  17  in a semiconductor process by using a silicon substrate as the substrate  17 . 
     The module substrate  20  includes upper coupling electrodes  21  and  22 , via conductors  23  and  24 , and lower coupling electrodes  25  and  26  all of which are formed in or on the substrate  27 . The lower coupling electrodes  25  and  26  are coupled to the upper coupling electrodes  21  and  22  with the via conductors  23  and  24  interposed therebetween, respectively. 
     The module substrate  20  may be, for example, a multilayer wiring substrate in which a plurality of base material layers made of a resin material or a ceramic material are laminated. 
     The coupler component  10  is mounted on the module substrate  20  by bonding the coupling electrodes  15  and  16  of the coupler component  10  and the upper coupling electrodes  21  and  22  of the module substrate  20  with a conductive bonding material  30  such as solder. Accordingly, the lower coupling electrodes  25  and  26  are respectively connected to one end and the other end of the main line  11 , and function as the input port IN and the output port OUT. 
     The module substrate  20  is provided with lower coupling electrodes that are coupled to one end and the other end of the sub-line  12  in a similar manner and that function as the first port P 1  and the second port P 2  (not illustrated). 
     The coupler module  1  is coupled to an external device that utilizes the coupler module  1  through the lower coupling electrodes of the module substrate  20  including the lower coupling electrodes  25  and  26 . 
     The coupler component  10  is mounted alone on the module substrate  20  or is mounted together with other components on the module substrate  20 . As described above, when the coupler component  10  is mounted on the module substrate  20 , an effective coupling degree of the directional coupler in the coupler component  10  may vary due to the influence of a parasitic component of the module substrate  20  and the influence of the other components mounted together with the coupler component  10  on the module substrate  20 . The variation in coupling degree may be a factor that impairs the accuracy of a detection signal outputted from the directional coupler. 
     Although the coupling degree of the directional coupler can be corrected by modifying the coupler component  10 , when the coupler component  10  is configured of an integrated circuit chip, it takes a great deal of time and cost to modify the coupler component  10 . 
     Thus, the inventors have conducted intensive studies on a coupler module capable of adjusting a coupling degree in a shorter period of time and at a lower cost, and as a result, the inventors have conceived of a coupler module having the following structure. 
     Each of  FIGS.  3 A and  3 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 1, and  FIG.  3 A  is a plan view and  FIG.  3 B  is a side view. As illustrated in  FIGS.  3 A and  3 B , in a coupler module  1   a , a wiring conductor  22   a  is added to a module substrate  20   a , and the arrangement of a via conductor  24   a  and a lower coupling electrode  26   a  is changed as compared with the coupler module  1  in  FIGS.  2 A and  2 B . The coupler component  10  is not changed. 
     In  FIGS.  3 A and  3 B , constituent elements that are added to or changed from the coupler module  1  among the constituent elements of the module substrate  20   a  are highlighted by hatching lines, and signs of some constituent elements among the constituent elements of the coupler component  10  are omitted. 
     As illustrated in  FIGS.  3 A and  3 B , the wiring conductor  22   a  is formed on an upper surface of the module substrate  20   a , one end thereof is coupled to the upper coupling electrode  22 , and the other end thereof is coupled to the lower coupling electrode  26   a  with the via conductor  24   a  interposed therebetween. The wiring conductor  22   a  is an example of a wiring coupled in series with the main line  11 . 
     In plan view, at least a part (for example, a portion A) of the wiring conductor  22   a  is provided along the main line  11 . Here, the fact that a part of the wiring conductor  22   a  is along the main line  11  means that the shortest distance (the shortest distance projected onto an XY plane in the example of  FIGS.  3 A and  3 B ) in plan view between a part of the wiring conductor  22   a  and the main line is maintained at a substantially constant value including a distance of zero. Note that the case where the shortest distance between the part of the wiring conductor  22   a  and the main line is maintained at the distance of zero indicates a case where the part of the wiring conductor  22   a  overlaps with the main line in plan view. 
     By arranging the portion A of the wiring conductor  22   a  along the main line  11 , an effective coupling degree of a directional coupler can be adjusted by causing a magnetic field obtained by synthesizing a magnetic field generated in the portion A of the wiring conductor  22   a  with a magnetic field generated in the main line  11  by the main signal to act on the sub-line  12 . 
     For example, in the coupler module  1  in  FIGS.  2 A and  2 B , it is assumed that the coupling degree is deviated when the coupler component  10  is mounted on the module substrate  20 . In this case, by changing the module substrate  20  to the module substrate  20   a  provided with the wiring conductor  22   a  having the portion A along the main line  11  in plan view as illustrated in  FIGS.  3 A and  3 B , the coupling degree can be corrected. 
     Since the portion A of the wiring conductor  22   a  can be provided in a region overlapping with the coupler component  10  in plan view, the coupling degree can be adjusted without an increase in size of the coupler module  1   a . Further, since the module substrate  20   a  is corrected, the coupling degree can be adjusted at a low cost and in a short period of time, as compared with the case where the coupler component  10  itself is corrected. 
       FIG.  4    is a graph showing an example of the effective coupling degree of the directional coupler in the coupler module  1 . In the example of  FIG.  4   , at a frequency of 3.7 GHz assumed to be utilized, a coupling degree FWD in the forward direction is −26.5 dB, and a coupling degree REV in the reverse direction is −24.6 dB. 
       FIG.  5    is a graph showing an example of the effective coupling degree of the directional coupler in the coupler module  1   a . In the example of  FIG.  5   , at the frequency of 3.7 GHz assumed to be utilized, a coupling degree FWD in the forward direction is −27.0 dB, and a coupling degree REV in the reverse direction is −25.4 dB. 
     From  FIG.  5    and  FIG.  4   , in the coupler module  1   a , the coupling degree in the forward direction is 0.5 dB smaller than that in the coupler module  1 , and the coupling degree in the reverse direction is 0.8 dB smaller than that in the coupler module  1 . 
     In the coupler module  1   a , a direction of a main signal flowing through the main line  11  and a direction of the main signal flowing through the portion A of the wiring conductor  22   a  are opposite to each other. Therefore, it is considered that the effective coupling degree of the directional coupler decreases due to the fact that the magnetic field in or around the portion A of the wiring conductor  22   a  and the magnetic field in or around the main line  11  that are in opposite directions to each other are generated by the main signal, and the magnetic field acting on the sub-line is weakened. 
     As described above, by providing, on the module substrate, a wiring which is coupled in series with the main line, at least a part of which is along the main line, and in which a direction of a main signal flowing through the part is opposite to the direction of the main signal flowing through the main line, it is possible to reduce the effective coupling degree of the directional coupler. 
     Embodiment 2 
     A coupler module according to Embodiment 2 will be described. 
     Each of  FIGS.  6 A and  6 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 2, and  FIG.  6 A  is a plan view and  FIG.  6 B  is a side view. As illustrated in  FIGS.  6 A and  6 B , in a coupler module  1   b , a wiring conductor  22   b  is added on a module substrate  20   b , and the arrangement of a via conductor  24   b  and a lower coupling electrode  26   b  is changed as compared with the coupler module  1  in  FIGS.  2 A and  2 B . The coupler component  10  is not changed. 
     In  FIGS.  6 A and  6 B , constituent elements that are added to or changed from the coupler module  1  among the constituent elements of the module substrate  20   b  are highlighted by hatching lines, and the signs of some constituent elements among the constituent elements of the coupler component  10  are omitted. 
     As illustrated in  FIGS.  6 A and  6 B , the wiring conductor  22   b  is formed on an upper surface of the module substrate  20   b , one end thereof is coupled to the upper coupling electrode  22 , and the other end thereof is coupled to the lower coupling electrode  26   b  with the via conductor  24   b  interposed therebetween. The wiring conductor  22   b  is an example of a wiring coupled in series with the main line  11 . 
     At least a part (for example, a portion B) of the wiring conductor  22   b  overlaps with the sub-line  12  in plan view. Since the portion B of the wiring conductor  22   b  is arranged so as to overlap with the sub-line  12 , the effective coupling degree of the directional coupler can be increased by forming the capacitive coupling between a part of the wiring and the sub-line. 
     In addition, in the coupler module  1   b , a direction of a main signal flowing through the wiring conductor  22   b  is the same as a direction of the main signal flowing through the main line  11 . Specifically, for example, in the case where the main signal in the forward direction flows, the main signal flowing through the main line  11  flows in a clockwise direction from the upper coupling electrode  21  side toward the upper coupling electrode  22  side, and the main signal flowing through the wiring conductor  22   b  flows in the clockwise direction from the upper coupling electrode  22  side toward the lower coupling electrode  26   b  side. 
     In this case, since a direction of a magnetic flux generated by the main signal flowing through the main line  11  and a direction of a magnetic flux generated by the main signal flowing through the wiring conductor  22   b  are in the same direction, an inductance component which the main line  11  has increases. Then, since the main line  11  and the sub-line  12  form stronger magnetic field coupling, it is considered that the effective coupling degree of the directional coupler can also be increased by the magnetic field coupling. 
     For example, in the coupler module  1  in  FIGS.  2 A and  2 B , it is assumed that the coupling degree is insufficient when the coupler component  10  is mounted on the module substrate  20 . In this case, the coupling degree can be compensated by changing the module substrate  20  to the module substrate  20   b  provided with the wiring conductor  22   b  having the portion B overlapping with the sub-line  12  in plan view as illustrated in  FIGS.  6 A and  6 B . 
     Since the portion B of the wiring conductor  22   b  can be provided in a region overlapping with the coupler component  10  in plan view, the coupling degree can be adjusted without an increase in size of the coupler module  1   b . Further, since the module substrate  20   b  is corrected, the coupling degree can be adjusted at a low cost and in a short period of time, as compared with the case where the coupler component  10  itself is corrected. 
       FIG.  7    is a graph showing an example of the effective coupling degree of the directional coupler in the coupler module  1   b . In the example of  FIG.  7   , at the frequency of 3.7 GHz assumed to be utilized, a coupling degree FWD in the forward direction is −25.9 dB, and a coupling degree REV in the reverse direction is −24.8 dB. 
     From  FIG.  7    and  FIG.  4   , in the coupler module  1   b , the coupling degree in the forward direction is 0.6 dB larger than that in the coupler module  1 , and the coupling degree in the reverse direction is 0.2 dB larger than that in the coupler module  1 . 
     In the coupler module  1   b , the wiring conductor  22   b  is coupled to an output end (an end portion on the output port OUT side) of the main line  11 . Thus, it is considered that the coupling degree in the forward direction, of the coupling degree in the forward direction and the coupling degree in the reverse direction, can be selectively increased due to the asymmetry of the circuit. 
     Further, by selectively increasing the coupling degree in the forward direction, a difference between the coupling degree in the forward direction and the coupling degree in the reverse direction is 1.1 dB in the coupler module  1   b . As described above, since the difference between the coupling degree in the forward direction and the coupling degree in the reverse direction in the coupler module  1   b  is a smaller value than 1.9 dB which is a difference between the coupling degree in the forward direction and the coupling degree in the reverse direction in the coupler module  1 , the directional coupler having better characteristics in which a mismatch between the coupling degree in the forward direction and the coupling degree in the reverse direction is improved can be obtained. 
     As described above, by providing, on the module substrate, a wiring which is coupled in series with the main line and at least partially overlaps with the sub-line, it is possible to increase the effective coupling degree of the directional coupler. In particular, it is possible to selectively increase the coupling degree in the forward direction by coupling the wiring at least partially overlapping with the sub-line to the output end of the main line. Due to this, the directional coupler having the better characteristics in which the mismatch between the coupling degree in the forward direction and the coupling degree in the reverse direction is improved can be obtained, for example, when the coupling degree in the forward direction is lower than the desired coupling degree. 
     In  FIGS.  6 A and  6 B , an example has been described in which the wiring conductor  22   b  at least partially overlapping with the sub-line  12  is coupled to the output end of the main line  11 , but a similar wiring is not limited to being coupled to the output end of the main line  11 , and may be coupled to the input end (an end portion on the input port IN side). 
     Each of  FIGS.  8 A and  8 B  is a diagram illustrating an example of a structure of a coupler module according to a modified example of the second embodiment, and  FIG.  8 A  is a plan view and  FIG.  8 B  is a side view. As illustrated in  FIGS.  8 A and  8 B , in a coupler module  1   c , a wiring conductor  21   c  is added on the module substrate  20   c , and the arrangement of a via conductor  23   c  and a lower coupling electrode  25   c  is changed as compared with the coupler module  1  in  FIGS.  2 A and  2 B . The coupler component  10  is not changed. In  FIGS.  8 A and  8 B , constituent elements that are added to or changed from the coupler module  1  among the constituent elements of the module substrate  20   c  are highlighted by hatching lines, and the signs of some constituent elements among the constituent elements of the coupler component  10  are omitted. 
     As illustrated in  FIGS.  8 A and  8 B , the wiring conductor  21   c  is formed on an upper surface of the module substrate  20   c , one end thereof is coupled to the upper coupling electrode  21 , and the other end thereof is coupled to the lower coupling electrode  25   c  with the via conductor  23   c  interposed therebetween. The wiring conductor  21   c  is an example of a wiring coupled in series with the main line  11 . At least a part (for example, a portion C) of the wiring conductor  21   c  overlaps with the sub-line  12  in plan view. 
     In the coupler module  1   c , the wiring conductor  21   c  is coupled to an input end (an end portion on the input port IN side) of the main line  11 . Thus, it is considered that the coupling degree in the reverse direction, of the coupling degree in the forward direction and the coupling degree in the reverse direction, can be selectively increased due to the asymmetry of the circuit. 
     As described above, by providing, on the module substrate, the wiring which is coupled in series with the main line and at least partially overlaps with the sub-line, it is possible to increase the effective coupling degree of the directional coupler. In particular, it is possible to selectively increase the coupling degree in the reverse direction by coupling the wiring at least a part of which overlaps with the sub-line to the input end of the main line. Thus, it is possible to obtain the directional coupler having better characteristics in which a mismatch between the coupling degree in the forward direction and the coupling degree in the reverse direction is improved, for example, when the coupling degree in the reverse direction is lower than the desired coupling degree. 
     Embodiment 3 
     A coupler module according to Embodiment 3 will be described. 
     Each of  FIGS.  9 A and  9 B  is a diagram illustrating an example of a structure of a coupler module according to Embodiment 3, and  FIG.  9 A  is a plan view and  FIG.  9 B  is a side view. As illustrated in  FIGS.  9 A and  9 B , in a coupler module  1   d , a wiring conductor  22   d  is added to a module substrate  20   d , and the arrangement of a via conductor  24   d  and a lower coupling electrode  26   d  is changed as compared with the coupler module  1  in  FIGS.  2 A and  2 B . The coupler component  10  is not changed. In  FIGS.  9 A and  9 B , constituent elements that are added to or changed from the coupler module  1  among the constituent elements of the module substrate  20   d  are highlighted by hatching lines, and the signs of some constituent elements among the constituent elements of the coupler component  10  are omitted. 
     As illustrated in  FIGS.  9 A and  9 B , the wiring conductor  22   d  is formed on an upper surface of the module substrate  20   d , one end thereof is coupled to the upper coupling electrode  22 , and the other end thereof is coupled to a lower coupling electrode  26   d  with a via conductor  24   d  interposed therebetween. The wiring conductor  22   d  is an example of a wiring coupled in series with the main line  11 . 
     At least a part (for example, a portion D) of the wiring conductor  22   d  overlaps with the sub-line  12  in plan view. Since the portion D of the wiring conductor  22   d  is arranged so as to overlap with the sub-line  12 , the effective coupling degree of the directional coupler can be increased by forming the capacitive coupling between a part of the wiring and the sub-line, similarly to the coupler module  1   b  illustrated in  FIGS.  6 A and  6 B . 
     In the coupler module  1   d , the wiring conductor  22   d  is disposed further away from the main line  11  than the coupler module  1   b . With such arrangement, an area increases in which the sub-line  12  overlaps with the main line  11  and the line conductor  22   d  through which a main signal flows in the same direction as the main line  11 , and thus, a magnetic flux acting on the sub-line  12  among the magnetic fluxes generated by the main signal flowing through the main line  11  and the wiring conductor  22   d  increases, and the coupling degree can be further increased in the coupler module  1   d  as compared with the coupler module  1   b.    
       FIG.  10    is a graph showing an example of the effective coupling degree of the directional coupler in the coupler module  1   d . In the example of  FIG.  10   , at a frequency of 3.7 GHz assumed to be utilized, a coupling degree FWD in the forward direction is −25.2 dB, and a coupling degree REV in the reverse direction is −24.2 dB. 
     From  FIG.  10    and  FIG.  7   , in the coupler module  1   d , the coupling degree in the forward direction is 0.7 dB larger than that in the coupler module  1   b , and the coupling degree in the reverse direction is 0.6 dB larger than that in the coupler module  1   b.    
     As described above, the coupling degree can be further increased by disposing the wiring at least a part of which overlaps with the sub-line so as to be further away from the main line. 
     The coupler module of the present disclosure has been described above based on the embodiments, but the present disclosure is not limited to the individual embodiments. Configurations in which various modifications that are conceived by those skilled in the art are adopted to the embodiments, or configurations created by combining constituent elements in different embodiments without departing from the spirit of the present disclosure may also be included in the scope of one or a plurality of aspects of the present disclosure. 
     For example,  FIGS.  3 A and  3 B  illustrate the example in which the direction of the main signal flowing through the main line  11  and the direction of the main signal flowing in the portion A are opposite to each other in the wiring conductor  22   a  having the portion A along the main line  11 , but the present disclosure is not limited to this example. The wiring conductor may be provided such that the direction of the main signal flowing through the main line and the direction of the main signal flowing in the portion along the main line of the wiring conductor are the same as each other. 
     Each of  FIGS.  11 A and  11 B  is a diagram illustrating an example of a structure of a coupler module according to a modified example, and  FIG.  11 A  is a plan view and  FIG.  11 B  is a side view. As illustrated in  FIGS.  11 A and  11 B , in a coupler module  1   e , a wiring conductor  22   e  is added to a module substrate  20   e , and the arrangement of a via conductor  24   e  and a lower coupling electrode  26   e  is changed as compared with the coupler module  1  in  FIGS.  2 A and  2 B . The coupler component  10  is not changed. In  FIGS.  11 A and  11 B , constituent elements that are added to or changed from the coupler module  1  among the constituent elements of the module substrate  20   e  are highlighted by hatching lines, and the signs of some constituent elements among the constituent elements of the coupler component  10  are omitted. 
     As illustrated in  FIGS.  11 A and  11 B , the wiring conductor  22   e  is formed on an upper surface of the module substrate  20   e , one end thereof is coupled to the upper coupling electrode  22 , and the other end thereof is coupled to the lower coupling electrode  26   e  with the via conductor  24   e  interposed therebetween. The wiring conductor  22   e  is an example of a wiring coupled in series with the main line  11 . 
     At least a part (for example, a portion E) of the wiring conductor  22   e  is provided along the main line  11 . Here, the fact that the part of the wiring conductor  22   e  is along the main line  11  means that a distance between a part of the wiring conductor  22   e  and the main line is kept substantially constant. 
     In the coupler module  1   e , a direction of a main signal flowing through the main line  11  is the same as a direction of the main signal flowing in the portion E of the wiring conductor  22   e . Thus, it is considered that magnetic fields in the same direction are generated by the main signal in or around the portion E of the wiring conductor  22   e  and in or around the main line  11 , a magnetic field acting on the sub-line is strengthened, and the effective coupling degree of the directional coupler increases. 
     As described above, by providing, on the module substrate, a wiring which is coupled in series with the main line, at least a part of which is along the main line, and in which the direction of the main signal flowing through the part is the same as the direction of the main signal flowing through the main line, the effective coupling degree of the directional coupler can be increased. 
     In addition, in the coupler module  1   e , a part of the wiring conductor  22   e  in plan view is provided along the sub-line  12  in the portion E, for example. Here, the fact that the part of the wiring conductor  22   e  is along the sub-line  12  means that a distance between the part of the wiring conductor  22   e  and the sub-line is kept substantially constant. 
     As described above, by providing a part of the wiring conductor in plan view so as to be along the sub-line, a magnetic field generated by the main signal on a part of the wiring is caused to act on the sub-line, and the effective coupling degree of the directional coupler can be further increased. 
     In addition, in the embodiments and the modified examples, in  FIGS.  3 A,  3 B,  6 A,  6 B,  8 A,  8 B,  9 A,  9 B,  11 A, and  11 B , the structure is exemplified in which the upper coupling electrode and the lower coupling electrode on the module substrate are at the same position in plan view of the substrate, but the present disclosure is not limited to this example. The lower coupling electrode of the module substrate may be disposed at any position, for example, through a wiring conductor provided in an inner layer of the module substrate. 
     The lower coupling electrode of the module substrate according to the embodiments and the modified examples may be arranged at the same position as the lower coupling electrode in the coupler module  1  having the basic structure, for example. This makes it possible to obtain a coupler module in which positions of the electrodes are interchangeable and the coupling degree of the directional coupler is adjusted, compared to the coupler module  1  having the basic structure. 
     Additionally, the wiring provided on the module substrate may not be formed on the upper surface of the module substrate. For example, even when the wiring coupled in series with the main line is formed inside the module substrate, a similar effect can be obtained as long as a shield layer is not interposed between the wiring and the coupler component. In this case, the closer the distance between the wiring and the main line or the sub-line is, the more easily the coupling degree of the directional coupler is adjusted by using magnetic field coupling or capacitive coupling. 
     SUMMARY 
     As described above, the coupler module according to an aspect of the present disclosure includes a component formed with a main line and a sub-line that configure a directional coupler, and a substrate on which the component is mounted and on which a wiring coupled in series with the main line is formed, and at least a part of the wiring is along the main line in plan view of the substrate. 
     With this, a magnetic field obtained by synthesizing the magnetic fields generated by a main signal in or around a part of the wiring with the magnetic fields generated in or around the main line is caused to act on the sub-line, capacitive coupling is formed between the part of the wiring line and the sub-line, and thus, an effective coupling degree of the directional coupler can be adjusted. For example, in a case where the coupling degree is deviated when the directional coupler is mounted on the substrate, the coupling degree can be corrected by changing the wiring of the substrate so as to have a portion along the main line in plan view of the substrate. Since the portion of the wiring along the main line can be provided in a region overlapping with the directional coupler in plan view of the substrate, the coupling degree can be adjusted without an increase in size of the coupler module. Further, since the substrate is modified, the coupling degree can be adjusted at a low cost and in a short period of time, as compared with a case where the directional coupler itself is corrected. 
     In addition, a direction of the main signal flowing through the main line and a direction of the main signal flowing through the at least part of the wiring may be opposite to each other. 
     As a result, magnetic fields in opposite directions to each other are generated by the main signal in or around the portion of the wiring conductor and in or around the main line, a magnetic field acting on the sub-line is weakened, and thus it is possible to reduce the effective coupling degree of the directional coupler. 
     In addition, the direction of the main signal flowing through the main line may be the same as the direction of the main signal flowing through the at least part of the wiring. 
     Due to this, the magnetic fields in the same direction are generated by the main signal in or around the portion of the wiring and in or around the main line, the magnetic field acting on the sub-line is strengthened, and thus, the effective coupling degree of the directional coupler can be increased. 
     A coupler module according to an aspect of the present disclosure includes a component formed with a main line and a sub-line that configure a directional coupler, and a substrate on which the component is mounted and on which a wiring coupled in series with the main line is formed, and at least a part of the wiring overlaps with the sub-line in plan view of the substrate. 
     Accordingly, since capacitive coupling is formed between a part of the wiring and the sub-line, the effective coupling degree of the directional coupler can be increased. For example, in a case where the coupling degree is insufficient when the directional coupler is mounted on the substrate, the coupling degree can be compensated by changing the wiring on the substrate so as to have a portion overlapping with the sub-line in plan view of the substrate. Since the portion of the wiring overlapping with the sub-line can be provided in a region overlapping with the directional coupler in plan view of the substrate, the coupling degree can be adjusted without an increase in size of the coupler module. Further, since the substrate is modified, the coupling degree can be adjusted at a low cost and in a short period of time, as compared with a case where the directional coupler itself is corrected. 
     Further, the wiring may be coupled to an output end of the main line. 
     This makes it possible to selectively increase the coupling degree in the forward direction of the coupling degree in the forward direction and the coupling degree in the reverse direction. For example, when the directional coupler is mounted on the substrate, in a case where the coupling degree in the forward direction is much less than the coupling degree in the reverse direction, imbalance in coupling degree can be reduced. 
     Further, the wiring may be coupled to an input end of the main line. 
     This makes it possible to selectively increase the coupling degree in the reverse direction of the coupling degree in the forward direction and the coupling degree in the reverse direction. For example, when the directional coupler is mounted on the substrate, in a case where the coupling degree in the reverse direction is much less than the coupling degree in the forward direction, it is possible to reduce the imbalance in coupling degree. 
     In addition, the at least part of the wiring may be along the sub-line. 
     Thus, the effective coupling degree of the directional coupler can be further adjusted by causing the magnetic field generated in or around the part of the wiring by the main signal to act on the sub-line in addition to the capacitive coupling formed between the part of the wiring and the sub-line. 
     Additionally, the at least part of the wiring may be formed on a main surface on a side of the substrate on which the component is mounted. 
     This makes it possible to more reliably form the capacitive coupling or the magnetic field coupling between the at least part of the wiring and the sub-line. Therefore, the effective coupling degree of the directional coupler can be more easily adjusted. 
     The present disclosure is widely usable as a coupler module in which a directional coupler is mounted.
           1 ,  1   a ,  1   b ,  1   c ,  1   d ,  1   e  COUPLER MODULE     10  COUPLER COMPONENT     11  MAIN LINE     12  SUB-LINE     13 ,  14  VIA CONDUCTOR     15 ,  16  COUPLING ELECTRODE     20 ,  20   a ,  20   b ,  20   c ,  20   d ,  20   e  MODULE SUBSTRATE     21 ,  22  UPPER COUPLING ELECTRODE     21   c ,  22   a ,  22   b ,  22   d ,  22   e  WIRING CONDUCTOR     23 ,  23   c ,  24 ,  24   a ,  24   b ,  24   d ,  24   e  VIA CONDUCTOR     25 ,  25   c ,  26 ,  26   a ,  26   b ,  26   d ,  26   e  LOWER COUPLING ELECTRODE     30  CONDUCTIVE BONDING MATERIAL