JP2019102704A - Balun transformer and method of manufacturing the same - Google Patents

Abstract

To provide a balun transformer capable of reducing an insertion loss in a high-frequency region.SOLUTION: A balun transformer comprises: a core having a plurality of through-holes; and lead wires that forms first and second coils wound in two through-holes. First, second, third, and fourth lead wires are arranged so as to be partially parallel to each other. The first coil and the second coil are formed so that a first wound part 41 composed of two lead wires or two adjacent lead wires provided at the inside of a parallel line, a second wound part 42 configured by winding the parallel line while covering the first wound part by a plane part, and a third wound part 43 configured by winding the two lead wires configuring the first wound part or other two lead wires on the second wound part, are continuous. The first coil is composed of the first and second lead wires. A terminal end of the first lead wire and a starting end of the second lead wire are connected to form a first center tap, and a starting end of the first lead wire and a terminal end of the second lead wire serve as both end parts of the first coil. The second coil is composed of the third and fourth lead wires. A terminal end of the third lead wire and a starting end of the fourth lead wire are connected to form a second center tap, and a starting end of the third lead wire and a terminal end of the fourth lead wire serve as both end parts of the second coil.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a balun transformer and a method of manufacturing the same.

  In a set top box or the like, a balun transformer is used for single-end to differential conversion between a coaxial cable and an electronic circuit. A balun transformer capable of handling a wide band from low frequency to high frequency is formed by winding a core having a plurality of through holes, for example, two parallel parallel to the cross section orthogonal to the cross section, having a columnar shape with an elliptical cross section. Generally, a core provided with a through hole is used.

  For example, in Patent Document 1, a main winding portion and a branch winding portion are provided in a core having two through holes, and a main signal winding and a main ground winding are wound around the main winding portion, and the branch winding is performed. The branch signal winding and the branch grounding winding are wound around the wire portion and the main trunk signal winding is extended and wound, and the grounding end of the main grounding winding and the grounding end of the branch grounding winding, the output of the trunk signal winding A branch transformer is described in which the end and the anti-ground end of the branch ground winding, and the anti-branch end of the branch signal winding and the anti-ground end of the main ground winding are respectively connected, and stable coupling is achieved over the entire operating frequency range. It is believed that the amount can be maintained.

JP, 2002-246233, A

  In the balun transformer, a twisted wire obtained by twisting a plurality of conducting wires, or a parallel wire obtained by arranging and fusing a plurality of conducting wires in parallel may be used as a wire. In general, a twisted wire has high coupling between wires, and is considered to be effective for improving the characteristics in a high frequency region. However, in the case of using a twisted wire, it is necessary to untwist the twisted wire when it is wound around a winding and a terminal, which causes a problem that the manufacturing process becomes complicated. When parallel lines are used, there is a case where it is difficult to achieve sufficient high frequency characteristics although it is not necessary to untwist.

  In view of the above problems, the present invention aims to provide a balun transformer in which the insertion loss in a high frequency region is reduced and a method of manufacturing the same.

  The balun transformer according to the present invention comprises a core having a plurality of through holes, and a plurality of conducting wires wound around a portion between two through holes of the core to form a first coil and a second coil. The plurality of conductors include parallel lines in which the first conductor, the second conductor, the third conductor, and the fourth conductor are disposed in parallel and have a flat portion. The first coil and the second coil are disposed at the inner side of two non-adjacent conductive wires of the parallel wire or at the inner side of the parallel wire, and a first winding portion formed by winding the adjacent two conductive wires; A second winding portion in which a parallel wire is wound by covering the first winding portion with the flat portion, and two conductive wires constituting the first winding portion or two other conductive wires And a third winding portion wound on the second winding portion is continuously formed. The first coil is formed of non-adjacent first and second conductors of the parallel wire, and the end of the first conductor on the winding end side is connected to the end of the second conductor on the winding start side. It has one center tap, and the end of the winding start side of the first lead and the end of the winding end of the second lead are both ends of the first coil. The second coil is formed of the third lead and the fourth lead of the parallel wire, and the second center to which the end at the winding end of the third lead and the end at the winding start of the fourth lead are connected It has a tap and the end of the winding start side of the 3rd lead and the end of the winding end of the 4th lead are the both ends of the 2nd coil.

A method of manufacturing a balun transformer comprising a core and a first coil having a first center tap and a second coil having a second center tap comprises: preparing a core having at least two through holes; Providing a parallel line in which the conductor, the third conductor and the fourth conductor are arranged in parallel and having a flat part, and in the part between the two through holes of the core, from the parallel line Forming a first winding portion by winding two adjacent non-adjacent conducting wires or two adjacent conducting wires disposed inside the parallel wire, and subsequently forming the first winding portion Covering with the flat portion of the parallel wire and winding the parallel wire to form a second winding portion; subsequently, the first wire separated from the parallel wire on the second winding portion Two wires that make up the winding section or others And forming a third winding portion wound two conductors,
including. The first coil is formed of non-adjacent first and second conductors of the parallel wire, and the end of the first conductor on the winding end side is connected to the end of the second conductor on the winding start side. It has one center tap, and the end of the winding start side of the first lead and the end of the winding end of the second lead are both ends of the first coil. The second coil is formed of the third lead and the fourth lead of the parallel wire, and the second center to which the end at the winding end of the third lead and the end at the winding start of the fourth lead are connected It has a tap terminal, and the end by the side of a winding start of the above-mentioned 3rd lead and the end by the side of a winding end of the above-mentioned 4th lead are the both ends of the above-mentioned 2nd coil.

  According to the present invention, it is possible to provide a balun transformer and a method of manufacturing the same, in which insertion loss in a high frequency region is reduced.

It is a partially transparent perspective view of a balun transformer. FIG. 6 is a conceptual diagram illustrating the winding state of the balun transformer of the first embodiment. FIG. 6 is an equivalent circuit diagram of a balun transformer of the first embodiment. FIG. 5 is a schematic cross-sectional view for explaining a winding state of the balun transformer of the first embodiment. FIG. 6 is a graph showing the insertion loss characteristic of the balun transformer of the first embodiment. It is sectional drawing which shows an example of a core. It is sectional drawing which shows an example of a core. It is sectional drawing which shows an example of a core. It is a schematic sectional drawing explaining the winding state of a balun transformer.

  The balun transformer includes a core having a plurality of through holes, and a plurality of conductive wires wound around a portion between two through holes of the core to form a first coil and a second coil. The plurality of conductors include parallel lines in which the first conductor, the second conductor, the third conductor, and the fourth conductor are disposed in parallel and have a flat portion. The first coil and the second coil are disposed at the inner side of two non-adjacent conductive wires of the parallel wire or at the inner side of the parallel wire, and a first winding portion formed by winding the adjacent two conductive wires; A second winding portion in which a parallel wire is wound by covering the first winding portion with the flat portion, and two conductive wires constituting the first winding portion or two other conductive wires And a third winding portion wound on the second winding portion is continuously formed. The first coil is formed of non-adjacent first and second conductors of the parallel wire, and the end of the first conductor on the winding end side is connected to the end of the second conductor on the winding start side. It has one center tap, and the end of the winding start side of the first lead and the end of the winding end of the second lead are both ends of the first coil. The second coil is formed of the third lead and the fourth lead of the parallel wire, and the second center to which the end at the winding end of the third lead and the end at the winding start of the fourth lead are connected It has a tap and the end of the winding start side of the 3rd lead and the end of the winding end of the 4th lead are the both ends of the 2nd coil.

  In the balun transformer, the first lead and the second lead which are not adjacent to each other in the parallel line form a first coil, and the remaining third lead and the fourth lead form a second coil. The conductive wire forming the first coil sandwiches the conductive wire forming the second coil, whereby the coupling between the first coil and the second coil becomes high, and in particular, the insertion loss in the high frequency region can be reduced. In addition, since a part of the parallel wire is split to wind the conducting wire, it is possible to avoid the trouble of untwisting the twist as in the case of the twist wire, and to prevent the manufacturing process from being complicated.

  The parallel wire may be disposed in this order with the first wire, the third wire, the fourth wire and the second wire. The first lead and the second lead forming the first coil form the second coil, and sandwiching the third lead and the fourth lead arranged side by side, the coupling of the first coil and the second coil Is further improved, and the insertion loss in the high frequency region is further reduced.

  The parallel lines may be arranged in this order of the first lead, the third lead, the second lead and the fourth lead. By alternately sandwiching the first wire and the second wire forming the first coil and the third wire and the fourth wire forming the second coil, the coupling of the first coil and the second coil is achieved. This improves the insertion loss in the high frequency region.

  The two through holes of the core may have an arc section in a cross section orthogonal to the penetration direction, and may be disposed with the arc section mutually sandwiching the portion between the through holes. The winding of the conducting wire can be effectively suppressed by winding the conducting wire around the arc portion.

  The two through holes of the core may have linear portions in cross section orthogonal to the penetrating direction, and the linear portions may be parallel to each other so as to sandwich a portion between the through holes. The winding of the conducting wire can be effectively suppressed by winding the conducting wire around the flat portion.

  The through hole may have a groove for accommodating the first winding portion. By the first winding portion being accommodated in the groove portion, it is possible to more effectively suppress the winding collapse of the second winding portion.

  The second winding portion may be formed by passing the parallel line at least twice through at least one of the through holes, and at least two flat portions of the parallel line may be disposed on the same plane. Since the parallel wires of the second winding portion are wound side by side, the coupling between the second coil and the first coil can be made higher, and the insertion loss in the high frequency region can be further reduced.

  The base portion includes a base portion on which the core is mounted, and the base portion includes a first terminal portion having at least three terminals to which both ends of the first coil and the center tap are respectively connected, and both ends of the second coil and And a second terminal portion having at least three terminals to which the center taps are respectively connected. By providing the base portion having the terminal portion, the mountability is improved.

  The first terminal portion and the second terminal portion may be respectively disposed on opposite side surfaces of the base portion. This further improves the implementation.

A method of manufacturing a balun transformer comprising a core and a first coil having a first center tap and a second coil having a second center tap comprises: preparing a core having at least two through holes; Providing a parallel line in which the conductor, the third conductor and the fourth conductor are arranged in parallel and having a flat part, and in the part between the two through holes of the core, from the parallel line Forming a first winding portion by winding two adjacent non-adjacent conducting wires or two adjacent conducting wires disposed inside the parallel wire, and subsequently forming the first winding portion Covering with the flat portion of the parallel wire and winding the parallel wire to form a second winding portion; subsequently, the first wire separated from the parallel wire on the second winding portion Two wires that make up the winding section or others And forming a third winding portion wound two conductors,
including. The first coil is formed of non-adjacent first and second conductors of the parallel wire, and the end of the first conductor on the winding end side is connected to the end of the second conductor on the winding start side. It has one center tap, and the end of the winding start side of the first lead and the end of the winding end of the second lead are both ends of the first coil. The second coil is formed of the third lead and the fourth lead of the parallel wire, and the second center to which the end at the winding end of the third lead and the end at the winding start of the fourth lead are connected It has a tap terminal, and the end by the side of a winding start of the above-mentioned 3rd lead and the end by the side of a winding end of the above-mentioned 4th lead are the both ends of the above-mentioned 2nd coil. Since a part of the parallel wire is split to wind the conductor, it is possible to avoid the complication of the manufacturing process without the need to take time to untwist the twist like a twist wire.

  Hereinafter, embodiments of the present invention will be described based on the drawings. However, the examples shown below illustrate balun transformer and its manufacturing method for embodying the technical idea of the present invention, and the present invention is limited to balun transformer shown below and its manufacturing method I will not. Further, the members shown in the claims are by no means limited to the members of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention thereto unless specifically described otherwise, but merely illustrative examples It is only Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for the sake of clarity. Further, in the following description, the same names and reference numerals indicate the same or the same members, and the detailed description will be appropriately omitted. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and one member is used in common as a plurality of elements, or conversely, the function of one member is realized by a plurality of members It can be shared and realized. Also, the contents described in some embodiments may be available for other embodiments.

Example 1
The balun transformer of the first embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a partially transparent perspective view of a balun transformer. FIG. 2 is a conceptual view for explaining the winding state of the coil. FIG. 3 is an equivalent circuit of a balun transformer. FIG. 4 is a cross-sectional view showing the winding state of the coil. FIG. 5 is a diagram showing the insertion loss characteristic of the balun transformer.

  In FIG. 1, the balun transformer 100 includes a core 20 having two through holes, a plurality of conducting wires 10 wound around a portion between the two through holes, and a base portion 30 on which the core 20 is mounted. Prepare. The two through holes of the core are disposed with the penetrating direction in parallel, and the cross section orthogonal to the penetrating direction is substantially circular. Therefore, the portion between the two through holes is sandwiched by the arc portion. The core is formed of, for example, a ferrite material such as a nickel material or a manganese material. The size of the through hole may be appropriately selected in accordance with the wire or the like to be wound, and for example, the plane portion of the parallel line can be wound on the same plane.

  A plurality of conducting wires 10 are wound around a portion between the two through holes to form a first coil and a second coil. A plurality of wires 10 are alternately and reversely passed through the two through holes and wound around the portion between the through holes, and the first coil having the two ends and the first center tap and the two ends and the second A second coil is formed having two center taps. Here, it is called 0.5 turn that the conductor passes through one through hole, and 1 turn that passes through the two through holes alternately and reversely. The plurality of conducting wires 10 are arranged such that the four conducting wires of the first conducting wire, the second conducting wire, the third conducting wire and the fourth conducting wire are arranged in parallel and have flat portions parallel to the extending direction and the arranging direction of the conducting wires. Contains now parallel lines. Each of the four conducting wires is a conductive wire coated with a thermoplastic resin such as polyurethane, and the four conducting wires are fused in parallel through an adhesive layer formed on the outer periphery of the insulating coating. A line is formed.

  The base portion 30 is formed of a thermosetting resin such as diallyl phthalate, and the first terminal portion and the second terminal portion are respectively provided on opposite side surfaces. The first terminal portion has three terminals 1, two terminals 2 and three terminals, and the second terminal portion has three terminals 4, five terminals 5 and six terminals 6. One end of the first coil is connected to the terminal 1 of the first terminal portion, a first center tap is connected to the terminal 2, and the other end of the first coil is connected to the terminal 3. One end of the second coil is connected to the terminal 4 of the second terminal portion, the second center tap is connected to the terminal 5, and the other end of the second coil is connected to the terminal 6. The terminals 1, 2, 3, 4, 5, and 6 are formed by applying tin plating and nickel plating to metals such as copper.

  FIG. 2 is a conceptual view schematically showing a winding state of the conducting wire 10 in Example 1, and FIG. 3 is an equivalent circuit diagram of a balun transformer. Conductor wire 10 wound around a portion between the through holes of the core includes a portion where lead A which is the first lead which is not adjacent in parallel and conductor D which is the second lead are separated from the parallel, and , A parallel wire portion in which a third wire, a fourth wire and a second wire are arranged in parallel in this order and integrated, and a wire B which is a third wire adjacent to the parallel line and a wire C which is a fourth wire It is formed to continuously include the part peeled off from the parallel line. In FIG. 2, the first winding portion 41 is formed by winding the non-adjacent conducting wire A and conducting wire D by 0.5 turns in a portion between two through holes of the core. Subsequently, a parallel wire in which the conducting wire A, the conducting wire B, the conducting wire C, and the conducting wire D are integrated is wound 2.5 turns on the first winding portion 41 to form a second winding portion 42. At this time, the parallel line is wound with the flat portion facing the first winding portion 41. That is, the second winding portion 42 is formed by covering the first winding portion 41 with the plane portion of the parallel line. Subsequently, the conductor B and the conductor C different from the conductor forming the first winding portion 41 are wound 0.5 turns on the second winding portion 42 to form the third winding portion 43.

  As shown in FIG. 3, the end on the winding start side of the conducting wire A separated from the parallel wire when forming the first winding portion 41 is connected to the terminal 1 as one end of the first coil. The end of the winding start side of the lead D which is simultaneously peeled is connected to the terminal 2 as one of the leads constituting the first center tap. The end on the winding end side of the conducting wire A separated from the parallel wire in forming the third winding portion 43 is connected to the terminal 2 as the other of the conducting wire constituting the first center tap. The end on the winding end side of the lead D which is simultaneously peeled off is connected to the terminal 3 as the other end of the first coil. Further, the end of the winding start side of the conductor B is connected to the terminal 4 as one end of the second coil, and the end of the winding end of the conductor B is connected to the terminal 5 as one of the conductors constituting the second center tap Be done. Also, the end on the winding start side of the conductor C is connected to the terminal 5 as the other of the conductors constituting the second center tap, and the end on the winding end side of the conductor C is connected to the terminal 6 as the other end of the second coil. Ru. The connection of the conducting wire to the terminal can be made by, for example, solder dipping, laser welding or the like. By these methods, the insulation coating is removed and the conducting wire is electrically connected to the terminal.

  In the balun transformer 100, a first coil is formed, and the first conducting wire and the second conducting wire not adjacent to each other in the parallel wire are wound by the first number of turns to form a first winding portion 41. Subsequently, the parallel wire in which the first wire, the third wire, the fourth wire, and the second wire are aligned in parallel in this order and integrated is wound by the second number of turns to form the second winding portion 42 . Then, a second coil is formed, and the third conducting wire and the fourth conducting wire, which are different from the conducting wire forming the first winding part 41, are wound by the first number of turns, and the third winding part 43 is It is formed. Thus, a balun transformer 100 is configured in which the number of turns of the first coil and the second coil is equal, that is, the impedance ratio is 1: 1.

  FIG. 4 is a schematic cross-sectional view showing an example of the arrangement of the leads in the cross section of the core orthogonal to the penetration direction of the two through holes. FIG. 4 is a cross-sectional view of the core passing through the line D-D in FIG. 1 and orthogonal to the penetrating direction of the through hole. In the parallel wire which comprises the 2nd winding part 42 in FIG. 4, the 1st lead (lead A) which forms the 1st coil, and the 2nd lead (lead D) form the 3rd lead (lead) which forms the 2nd coil. B) and the fourth conducting wire (conducting wire C) are sandwiched. That is, in FIG. 4, the first coil sandwiches the second coil. This improves the coupling between the first coil and the second coil, and in particular reduces the insertion loss in the high frequency range.

  FIG. 5 is a schematic diagram showing an example of the relationship of insertion loss (dB) to frequency (MHz) in the balun transformer of the first embodiment. Reference Example 1 in FIG. 5 shows the insertion loss of a balun transformer formed by winding in the same manner except that a 4-core twisted wire is used instead of a parallel wire, and Reference Example 2 corresponds to the second example in Example 1. The insertion loss of the balun transformer which switched the conductor (conductor D) and the 3rd conductor (conductor B) is shown. In FIG. 5, the insertion loss is particularly reduced in the high frequency region in the first embodiment. In the first embodiment, the insertion loss in the high frequency region is reduced as compared with the first embodiment using the twisted wire generally considered to have high coupling between the wires.

  In the balun transformer 100 of the first embodiment, the shape of the through hole in the cross section orthogonal to the through direction of the through hole of the core 20 is substantially circular, but the cross sectional shape of the through hole is not limited to circular. For example, the shape may be an elliptical shape, a shape having an arc portion and a straight portion, or a polygonal shape including a straight portion. Specifically, for example, the shapes shown as schematic cross-sectional views of the core in FIGS. 6A to 6C can be exemplified. In FIG. 6A, the through hole shape has an arc portion and a straight portion, and the two through holes sandwich the portion between the through holes with each other in the arc portion. In FIG. 6B, the through hole shape has an arc portion and a straight portion, and the two through holes make the straight portions parallel to each other and sandwich a portion between the through holes. In FIG. 6C, the through hole shape is a rectangular shape consisting of straight portions, and the two through holes make the straight portions parallel to each other and sandwich a portion between the through holes. In FIGS. 6A to 6C, although the two through holes have substantially the same shape and they are arranged in plane symmetry, the two through holes may have different shapes, even if they are asymmetrically provided. Good.

  The through hole in the balun transformer may have a groove that accommodates the first winding along the penetrating direction. The grooved portion further stabilizes the sandwiching state between the conducting wires. Thereby, the winding collapse of the conducting wire is suppressed, stable insertion loss characteristics are obtained, and the manufacturing efficiency becomes more efficient. A schematic cross-sectional view for explaining a winding state of a core provided with a through hole having a groove portion is shown in FIG. In FIG. 7, the cross section of the through hole has a polygonal shape consisting of straight portions. In the cross section of the through hole of FIG. 7, a groove portion for accommodating the first winding portion and the third winding portion is provided in the through hole of the rectangular cross section. The groove portion is provided along the penetrating direction in the surface sandwiching the portion between the rectangular through holes and the surface opposed thereto. The size of the groove portion is appropriately selected in accordance with the number of turns in the first winding portion and the third winding portion. In FIG. 7, in the portion where the second winding portion is formed, the height in the direction orthogonal to the mounting surface of the core is formed such that the plane portion of the parallel line can be disposed parallel to the height direction .

  Although the groove in which the third winding portion is accommodated is formed in FIG. 7, the groove which accommodates the third winding portion may not be provided. In addition, the through hole including the groove may have a cross-sectional shape including the arc portion. For example, the shape which provided the groove part which accommodates a 1st winding part in a substantially circular through hole may be sufficient. Furthermore, the cross-sectional shape of the groove portion is not limited to the rectangular shape, and may be a shape having an arc portion.

  In the balun transformer of the first embodiment, although the lead wire is directly connected to the terminal, as described in, for example, JP-A 2014-203989, a winding portion electrically connected to the terminal is provided, and the winding portion Wires may be connected to Alternatively, the first winding portion may be formed of the conducting wire B and the conducting wire C, and the third winding portion may be formed of the conducting wire A and the conducting wire D.

Example 2
In the balun transformer of Example 1, the first coil is formed by the non-adjacent first lead (lead A) and the second lead (lead D), and the adjacent third lead (lead B) and fourth lead (lead C) are formed. In the balun transformer according to the second embodiment, the first coil is formed by the non-adjacent first lead (lead A) and the second lead (lead C), and the second coil is not formed. The third coil (conductor B) and the fourth conductor (conductor D) form a second coil.

  In Example 2, the lead wound around the portion between the through holes of the core is a portion where the first lead (lead A) and the second lead (lead C) which are not adjacent in parallel are separated from the parallel. , A parallel wire portion in which the first wire (wire A), the third wire (wire B), the second wire (wire C) and the fourth wire (conductor D) are disposed in parallel in this order, and are integrated The third conducting wire (conducting wire B) and the fourth conducting wire (conducting wire D) which are not adjacent to each other in the wire continuously include the part peeled from the parallel wire. In the balun transformer of the second embodiment, the first lead (lead A) and the second lead (lead C) which are not adjacent to each other in parallel are wound 0.5 turns in a portion between two through holes of the core. One turn is formed. Subsequently, a parallel wire in which the first lead (lead A), the third lead (lead B), the second lead (lead C), and the fourth lead (lead D) are integrated on the first winding portion. .5 turns to form a second turn. At this time, the parallel line is wound with the flat portion facing the first winding portion. That is, the second winding portion is formed by covering the first winding portion with the flat portion of the parallel line. Subsequently, the third conducting wire (conducting wire B) and the fourth conducting wire (conducting wire D) different from the conducting wire forming the first winding portion are wound 0.5 turns on the second winding portion and the third winding A part is formed.

  In the balun transformer of the second embodiment, the first lead (lead A) and the second lead (lead C) which are not adjacent to each other in the parallel line forming the first coil are the third lead (lead B) in which the second coil is formed. The third conducting wire (conducting wire B) and the fourth conducting wire (conducting wire D) that sandwich and form the second coil sandwich the second conducting wire (conducting wire C) that forms the first coil. As a result, the first coil and the second coil are sandwiched between each other, the coupling between the first coil and the second coil is improved, and it is possible to configure a balun transformer in which the insertion loss in the high frequency region is reduced. In the balun transformer of the second embodiment, although the insertion loss in the high frequency region is slightly increased as compared to the balun transformer of the first embodiment, the insertion loss in the high frequency region is reduced as compared to the balun transformers of the reference example 1 and the second embodiment. It is done.

  In the balun transformer of the second embodiment, the first coil is formed, and the first conducting wire and the second conducting wire which are not adjacent in the parallel wire are wound by the first number of turns to form the first winding portion. Subsequently, a second winding part is formed by winding a parallel wire in which a first lead, a third lead, a second lead and a fourth lead are arranged in parallel in this order and integrated in a second number of turns. . Subsequently, the third conducting wire and the fourth conducting wire which are different from the conducting wire forming the second coil and the first winding portion are wound by the first number of turns to form the third winding portion Be done. As a result, a balun transformer is configured in which the number of turns of the first coil and the second coil is equal, that is, the impedance ratio is 1: 1.

Example 3
In the balun transformers of Examples 1 and 2, the first winding portion is formed of the non-adjacent conductive wires in the parallel wire, and the third winding portion is formed of the conductive wire different from the conductive wire forming the first winding portion. On the other hand, in the balun transformer of the third embodiment, the first winding portion is formed by the adjacent third conductive wire (conductive wire B) and fourth conductive wire (conductive wire C) disposed inside the parallel line, and the first winding portion is formed. A third winding is formed of the same wire as the wire forming the turn.

  In Example 3, the lead wound around the portion between the through holes of the core is the parallel lead of the third lead (lead B) and the fourth lead (lead C) which are disposed adjacent to each other in the parallel line. The part peeled from the first conductor (conductor A), the third conductor (conductor B), the fourth conductor (conductor C), and the second conductor (conductor D) are arranged in parallel in this order and integrated A parallel line portion and a portion in which a third conducting wire (conducting wire B) and a fourth conducting wire (conducting wire C) disposed adjacent to each other in the parallel line are continuously separated from the parallel line. In the balun transformer of the third embodiment, the third lead (lead B) and the fourth lead (lead C) adjacent to each other in parallel are wound 1.5 turns in a portion between two through holes of the core. One turn is formed. Subsequently, a parallel wire in which the first lead (lead A), the third lead (lead B), the third lead (lead C) and the second lead (lead D) are integrated on the first winding portion. The turn is wound to form a second winding portion. At this time, the parallel line is wound with the flat portion facing the first winding portion. That is, the second winding portion is formed by covering the first winding portion with the flat portion of the parallel line. Subsequently, the third conductor (conductor B) and the fourth conductor (conductor C), which are the same as the conductors forming the first winding portion, are wound 1.5 turns on the second winding portion. A winding part is formed.

  In the balun transformer of the third embodiment, in the parallel wire forming the second winding portion, the first conducting wire (conducting wire A) and the second conducting wire (conducting wire D) forming the first coil form the second coil. The three conductors (conductor B) and the fourth conductor (conductor C) are sandwiched. That is, the first coil sandwiches the second coil. This improves the coupling between the first coil and the second coil, and in particular reduces the insertion loss in the high frequency range.

  In the balun transformer of the third embodiment, the second coil is formed, and the third lead and the fourth lead adjacent to each other in the parallel wire are wound by a predetermined number of turns to form the first winding portion. Subsequently, a parallel wire in which the first conductor, the third conductor, the fourth conductor, and the second conductor are arranged in parallel in this order and integrated is wound with twice the predetermined number of turns to perform the second winding. A part is formed. Subsequently, the third conducting wire and the fourth conducting wire, which are the same as the conducting wire forming the first winding portion, are wound again by a predetermined number of turns to form a third winding portion. Thus, a balun transformer is configured in which the ratio of the number of turns of the first coil to the second coil is 1: 2, that is, the impedance ratio is 1: 4.

DESCRIPTION OF SYMBOLS 10 Conductor 20 Core 30 Base part 41 1st winding part 42 2nd winding part 43 3rd winding part 100 Balun transformer

Claims (12)

A core having a plurality of through holes, and a plurality of conducting wires wound around a portion between two through holes of the core to form a first coil and a second coil;
The plurality of conductors include parallel lines in which the first conductor, the second conductor, the third conductor, and the fourth conductor are disposed in parallel and have a flat portion.
The first coil and the second coil are
A first winding portion formed by winding two non-adjacent conductive wires of the parallel wire or two adjacent conductive wires disposed inside the parallel wire;
A second winding portion in which the parallel wire is wound by covering the first winding portion with the flat portion;
A third winding portion formed by winding the two conducting wires constituting the first winding portion or the other two conducting wires on the second winding portion;
The first coil is formed of non-adjacent first and second conductors of the parallel wire, and the end of the first conductor on the winding end side is connected to the end of the second conductor on the winding start side. Have one center tap,
The winding start end of the first wire and the winding end of the second wire are both ends of the first coil,
The second coil is formed of the third lead and the fourth lead of the parallel wire, and the second center to which the end at the winding end of the third lead and the end at the winding start of the fourth lead are connected Have a tap,
A balun transformer, wherein an end portion of the winding start side of the third wire and an end portion of the winding end side of the fourth wire are both ends of the second coil.   The first winding portion is formed by winding two non-adjacent conducting wires of the parallel wire, and the third winding portion is two wires other than the two conducting wires constituting the first winding portion. The balun transformer according to claim 1, wherein the lead wire is wound.   The first winding portion is formed by winding two adjacent conducting wires disposed inside the parallel wire, and the third winding portion includes two of the first winding portions. The balun transformer according to claim 1, wherein the wire is wound.   The balun transformer according to any one of claims 1 to 3, wherein the parallel wire is disposed in the order of the first conductor, the third conductor, the fourth conductor and the second conductor.   The balun transformer according to claim 1 or 2, wherein the parallel wire is disposed in the order of the first lead, the third lead, the second lead and the fourth lead.   The cross section perpendicular | vertical to the penetration direction has a circular arc part, and the two through holes of the said core are arrange | positioned across the part between through holes by the circular arc part of each other. Balun trance described in.   The two through holes of the core have straight portions in cross section perpendicular to the penetrating direction, and the straight portions are parallel to each other and disposed so as to sandwich a portion between the through holes. Balun trance described in any of the.   The balun transformer according to any one of claims 1 to 7, wherein the through hole has a groove for accommodating the first winding portion.   The second winding portion is formed by passing the parallel line at least twice through at least one of the through holes, and at least two flat portions of the parallel line are disposed on the same plane. The balun transformer according to any one of claims 8.   The base portion includes a base portion on which the core is mounted, and the base portion includes a first terminal portion having at least three terminals to which both ends of the first coil and a first center tap are connected, and both ends of the second coil. The balun transformer according to any one of claims 1 to 9, further comprising: a second terminal portion having at least three terminals to which the portion and the second center tap are respectively connected.   The balun transformer according to claim 10, wherein the first terminal portion and the second terminal portion are respectively disposed on opposite side surfaces of the base portion. A method of manufacturing a balun transformer comprising a core and a first coil having a first center tap and a second coil having a second center tap,
Preparing a core having at least two through holes;
Arranging the first conductor, the second conductor, the third conductor, and the fourth conductor in parallel and having a flat portion to form an integrated parallel line;
In a portion between two through holes of the core, a first winding portion is formed by winding two non-adjacent conductive wires separated from the parallel wire or two adjacent conductive wires disposed inside the parallel wire. To form
Subsequently, covering the first winding portion with a flat portion of the parallel line and winding the parallel line to form a second winding portion;
Subsequently, on the second winding portion, two conductive wires constituting the first winding portion separated from the parallel wire or two other conductive wires are wound to form a third winding portion. Forming and
Including
The first coil is formed of non-adjacent first and second conductors of the parallel wire, and the end of the first conductor on the winding end side is connected to the end of the second conductor on the winding start side. One end of the first coil, and the end on the winding start side of the first lead and the end on the winding end of the second lead are both ends of the first coil,
The second coil is formed of the third lead and the fourth lead of the parallel wire, and the second center to which the end at the winding end of the third lead and the end at the winding start of the fourth lead are connected The manufacturing method of having a tap terminal and the end by the side of the winding start of said 3rd conducting wire, and the end by the side of a winding end of said 4th conducting wire are the both ends of said 2nd coil.

Images