Signal transmission line and connector

Abstract

Provided is a signal transmission line having a first end portion that connects to a first differential transmission line and a second differential transmission line, the signal transmission line comprising: a plurality of conductor lines having, on the first end portion side, a plurality of connection end portions that connect to the first differential transmission line and the second differential transmission line; a holding portion that holds the plurality of conductor lines arranged along a predetermined arrangement direction; and a first shielding member that is disposed along the arrangement direction to face side surfaces of the plurality of conductor lines and shields electromagnetic waves radiated from the plurality of conductor lines.

Description

Signal Transmission Lines and Connectors

[0001] This application claims priority to Japanese Patent Application No. 2024-101376, filed on June 24, 2024, and incorporates by reference all of the contents of said Japanese application.

[0002] Patent Document 1 discloses a board-to-board connector. This board-to-board connector has a plurality of differential transmission lines. The plurality of differential transmission lines are arranged along a predetermined arrangement direction.

[0003] Japanese Patent Application Laid-Open No. 2005-149770

[0004] The signal transmission line of the embodiment is a signal transmission line having a first end connected to a first differential transmission line and a second differential transmission line, and includes a plurality of conductor lines having a plurality of connection ends connected to the first differential transmission line and the second differential transmission line on the first end side, a holding section that arranges and holds the plurality of conductor lines along a predetermined arrangement direction, and a first shielding member that is arranged opposite a side surface of the plurality of conductor lines along the arrangement direction and that shields electromagnetic waves radiated from the plurality of conductor lines.

[0005] FIG. 1 is a perspective view showing an example of a connector according to the first embodiment. FIG. 2 is a view showing a portion of a plug as viewed from the Y1 direction. FIG. 3 is a side view of a plug terminal and a socket terminal. FIG. 4 is a view showing a portion of a plug as viewed from the X1 direction. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4. FIG. 6 is a view of the first shielding member as viewed from the Y2 direction, showing an example of a periodic structure. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is a view showing a portion of a plug according to the second embodiment. FIG. 9 is a view showing a portion of a plug according to the third embodiment. FIG. 10 is a view showing a portion of a plug according to the fourth and fifth embodiments. FIG. 11 is a partial cross-sectional view of plugs according to the sixth, seventh, and eighth embodiments. FIG. 12 is a view showing a portion of a plug according to the ninth embodiment. FIG. 13 is a view showing a portion of a plug as viewed from the Y2 direction. FIG. 14 is a view of the first shielding member of the ninth embodiment as viewed from the Y2 direction, showing an example of a periodic structure. FIG. 15 is a graph showing the frequency characteristics of S21 for Example 1 and Comparative Example 1. FIG. 16 is a graph showing the frequency characteristics of S41 in Example 1 and Comparative Example 1. FIG. 17 is a graph showing the frequency characteristics of S31 in Example 1 and Comparative Example 1. FIG. 18 is a diagram showing an example of electric field distribution in the X-Y plane in Comparative Example 1. FIG. 19 is a diagram showing an example of electric field distribution in the X-Y plane in Example 1. FIG. 20 is a graph showing the frequency characteristics of S41 when the distance a in Example 1 is changed. FIG. 21 is a graph showing the frequency characteristics of S41 when the distance a in Example 1 is changed. FIG. 22 is a graph showing the frequency characteristics of S41 when the periodic structure in Example 1 is formed of nickel. FIG. 23 is a graph showing the frequency characteristics of S41 in Example 2. FIG. 24 is a graph showing the frequency characteristics of S41 in Example 3. FIG. 25 is a graph showing the frequency characteristics of S41 in Examples 4 and 5. FIG. 26 is a graph showing the frequency characteristics of S41 in Examples 6, 7, and 8. Fig. 27 is a graph showing the frequency characteristics of S41 in Comparative Examples 1 and 2. Fig. 28 is a graph showing the frequency characteristics of S31 in Comparative Examples 1 and 2. Fig. 29 is a graph showing the frequency characteristics of S41 in Example 9.Fig. 30 is a graph showing the frequency characteristics of S31 in Example 9. Fig. 31 is a diagram for explaining an incident wave with respect to the first shielding member of Example 1. Fig. 32 is a graph showing the frequency characteristics of the reflection loss when an incident wave is made incident on the first shielding member 26 of Example 1. Fig. 33 is a diagram in which the band near 4.74 GHz in Fig. 32 is enlarged. Fig. 34 is a diagram in which the band near 11.4 GHz in Fig. 32 is enlarged. Fig. 35 is a diagram in which the band near 17.5 GHz in Fig. 32 is enlarged. Fig. 36 is a graph showing the frequency characteristics of the reflection loss when an incident wave is made incident on the first shielding member of Example 9.

[0006] [Problem to be Solved by the Present Disclosure] In the above-described connector, crosstalk may occur between a pair of adjacent differential transmission lines among the multiple differential transmission lines, which may degrade communication quality. Therefore, a technology that can reduce crosstalk is desired.

[0007] An object of the present disclosure is to provide a technique that can reduce crosstalk.

[0008] [Effects of the Present Disclosure] According to the present disclosure, crosstalk can be reduced.

[0009] First, the contents of the embodiment will be listed and explained.

[0010] (1) A signal transmission line according to an embodiment of the present invention has a first end connected to a first differential transmission line and a second differential transmission line. The signal transmission line includes: a plurality of conductor lines having a plurality of connection ends connected to the first differential transmission line and the second differential transmission line at the first end; a holding portion that holds the plurality of conductor lines in an arrangement direction; and a first shielding member that is disposed opposite a side surface of the plurality of conductor lines in the arrangement direction and that shields electromagnetic waves radiated from the plurality of conductor lines. According to the above configuration, the first shielding member can prevent electromagnetic waves radiated from the plurality of conductor lines from circumventing each other between the plurality of conductor lines. As a result, crosstalk occurring between the plurality of conductor lines can be reduced when two-system signal transmissions via the first differential transmission line and the second differential transmission line are performed by the plurality of conductor lines.

[0011] (2) The signal transmission line of (1) may further include a second shielding member disposed opposite the first shielding member across the plurality of conductor lines, and configured to shield electromagnetic waves radiated from the plurality of conductor lines. In this case, electromagnetic waves circulating between the plurality of conductor lines can be suppressed from two directions, thereby more effectively reducing crosstalk.

[0012] (3) In the signal transmission line of (1) or (2) above, the first shielding member may be provided in a portion of the section from the first end to a second end on the opposite side of the first end in the direction in which the plurality of conductor lines extend. Crosstalk may occur significantly in a specific portion of the section from the first end to the second end. Therefore, by providing the first shielding member in the specific portion where crosstalk occurs significantly, crosstalk can be effectively reduced without providing the first shielding member over the entire area from the first end to the second end.

[0013] (4) In the signal transmission line of (1) or (2), the first shielding member may be provided at a position including a central portion between the first end and a second end opposite the first end in the direction in which the plurality of conductor lines extend. Crosstalk can occur significantly at a node of resonance occurring between the first end and the second end. Therefore, by providing the first shielding member so as to include the central portion, which can be a node of resonance occurring between the first end and the second end, crosstalk can be effectively reduced without providing the first shielding member over the entire area between the first end and the second end.

[0014] (5) In the signal transmission line of any one of (1) to (4), the plurality of conductor lines may include a pair of signal lines connected to the first differential transmission path and a pair of ground lines arranged on either side of the pair of signal lines, wherein a first ground line of the pair of ground lines is located at an end of the plurality of conductor lines in the arrangement direction, and the first shielding member may have a rectangular plate shape with a pair of sides extending along the direction in which the plurality of conductor lines extend, and when the first shielding member is viewed from the front, the side closest to the end of the pair of sides may be located on the first ground line. In this case, the first shielding member faces at least the side surfaces of the pair of signal lines of the plurality of conductor lines. Therefore, the first shielding member can prevent electromagnetic waves radiated from the pair of signal lines and the other conductor lines from diverging between each other.

[0015] (6) In the signal transmission line according to any one of (1) to (5), the first shielding member may include a rectangular ground conductor plate. In this case, the ground conductor plate can prevent electromagnetic waves radiated from the plurality of conductor lines from circulating between the plurality of conductor lines.

[0016] (7) In the signal transmission line according to any one of (1) to (5), the first shielding member may include a rectangular dielectric substrate having a first surface facing the conductor lines and a second surface opposite the first surface, and a ground conductor plate laminated on the second surface. In this case, the dielectric substrate and the ground conductor plate can prevent electromagnetic waves radiated from the conductor lines from diverging between the conductor lines.

[0017] (8) In the signal transmission line of (7), the first shielding member may further include one or more unit cells including a predetermined conductor pattern provided on the first surface. In this case, the one or more unit cells, the dielectric substrate, and the ground conductor plate can prevent electromagnetic waves radiated from the multiple conductor lines from diverging between the multiple conductor lines.

[0018] (9) In the signal transmission line of (7), the first shielding member may further include a periodic structure formed by periodically arranging a plurality of unit cells, each including a predetermined conductor pattern, on the first surface. In this case, the periodic structure, the dielectric substrate, and the ground conductor plate can prevent electromagnetic waves radiated from the plurality of conductor lines from diverging between the plurality of conductor lines.

[0019] (10) In the signal transmission line of (9), the periodic structure may further include a plurality of vias that penetrate the dielectric substrate and connect the plurality of unit cells to the ground conductor plate. In this case, the dielectric substrate, the periodic structure including the plurality of vias, and the ground conductor plate can prevent electromagnetic waves radiated from the plurality of conductor lines from diverging between the plurality of conductor lines.

[0020] (11) In the signal transmission line of (10), the plurality of conductor lines may include a pair of signal lines connected to the first differential transmission line and a pair of ground lines arranged on both sides of the pair of signal lines, a first ground line of the pair of ground lines being located at an end of the plurality of conductor lines in the arrangement direction, the periodic structure having a rectangular shape with a pair of structure sides along the longitudinal direction, and when the first shielding member is viewed from the front, the structure side on the end side of the pair of structure sides may be located closer to the pair of signal lines than the first ground line. In this case, if the structure side on the end side of the first shielding member is located outside the pair of signal lines, electromagnetic waves radiated from the pair of signal lines are shielded by the periodic structure.

[0021] (12) In the signal transmission line of (11), when the first shielding member is viewed from the front, the structure side on the end side may be located between the pair of signal lines. In this case, the periodic structure is disposed opposite a side surface of at least one of the pair of signal lines, and therefore electromagnetic waves radiated from one of the pair of signal lines are blocked by the first shielding member.

[0022] (13) In the signal transmission line of any one of (9) to (12) above, when the distance between the side surfaces of the plurality of conductor lines and the periodic structure is a and the pitch of the plurality of conductor lines in the arrangement direction is p, the following formula may be satisfied: 1 ≦ a / p ≦ 2. In this case, if a / p is smaller than 1, the first shielding member may affect the plurality of conductor lines. If a / p is larger than 2, the effect of shielding electromagnetic waves radiated from the plurality of conductor lines may not be sufficiently obtained. By setting a / p to be equal to or greater than 1 and equal to or less than 2, it is possible to appropriately shield electromagnetic waves radiated from the plurality of conductor lines.

[0023] (14) In the signal transmission line of any one of (8) to (13), the predetermined conductor pattern included in the unit cell may have a characteristic of attenuating electromagnetic waves in a predetermined frequency band among incident waves, and a resonant frequency occurring between the first end and a second end opposite the first end may be included in the predetermined frequency band. Crosstalk may occur at the resonant frequency occurring between the first end and the second end. Therefore, by ensuring that the resonant frequency is included in the frequency band that can be shielded by the conductor pattern, crosstalk can be effectively reduced.

[0024] (15) An embodiment from another perspective is a connector provided on a substrate, the connector having first ends connected to first and second differential transmission paths provided on the substrate, the connector including: a plurality of linear terminals having a plurality of connection ends connected to the first and second differential transmission paths on the first end side, a holding portion that holds the plurality of terminals in an array along a predetermined array direction, and a first shielding member that is arranged opposite a side surface of the plurality of terminals in the array direction and that shields electromagnetic waves radiated from the plurality of terminals.

[0025] [Details of the Embodiments] Preferred embodiments will now be described with reference to the drawings. It should be noted that at least some of the embodiments described below may be combined in any desired manner. [Regarding the First Embodiment] [Overall Configuration of the Connector] Fig. 1 is a perspective view showing an example of a connector according to the first embodiment. This connector 1 is a board-to-board connector that electrically connects a first circuit board 2 and a second circuit board 3.

[0026] In the following description, the three mutually orthogonal directions in each drawing are referred to as the X direction, Y direction, and Z direction. As shown in FIG. 1 , one of the X directions is referred to as the X1 direction, and the opposite direction of the X1 direction is referred to as the X2 direction. One of the Y directions is referred to as the Y1 direction, and the opposite direction of the Y1 direction is referred to as the Y2 direction. One of the Z directions is referred to as the Z1 direction, and the opposite direction of the Z1 direction is referred to as the Z2 direction.

[0027] 1, the first circuit board 2 and the second circuit board 3 are arranged parallel to the XY plane and have a rectangular shape with each side parallel to the X direction or the Y direction.

[0028] A first differential transmission path 4 and a second differential transmission path 5 are mounted on the surface of the first circuit board 2 on the Z1 direction side. The first differential transmission path 4 and the second differential transmission path 5 are provided parallel to each other along the Y direction. The Y1 direction end of the first differential transmission path 4 and the Y1 direction end of the second differential transmission path 5 are located on the Y1 direction side of the first circuit board 2.

[0029] The first differential transmission path 4 includes a pair of signal lines 4a. A differential transmission signal including a pair of signals having opposite phases is transmitted through the pair of signal lines 4a. The second differential transmission path 5 includes a pair of signal lines 5a. A differential transmission signal including a pair of signals having opposite phases is transmitted through the pair of signal lines 5a.

[0030] The Y1-direction end of the first differential transmission line 4 and the Y1-direction end of the second differential transmission line 5 are connected to the connector 1. The Y2-direction end of the first differential transmission line 4 and the Y2-direction end of the second differential transmission line 5 are connected to electronic components mounted on the first circuit board 2. These electronic components exchange differential transmission signals with the second circuit board 3. Note that FIG. 1 shows a portion of the first circuit board 2 including the edge on the Y1-direction side, and omits the portion of the first circuit board 2 on the Y2-direction side.

[0031] The first differential transmission line 4 and the second differential transmission line 5 are configured as coplanar lines. Therefore, ground conductors 8 are provided on the X2 direction side of the first differential transmission line 4, the X1 direction side of the second differential transmission line 5, and the portion between the two differential transmission lines 4 and 5. In addition, a ground conductor 9 is provided on the Z2 direction surface of the first circuit board 2. The ground conductors 8 and 9 are connected by a plurality of vias 10. The plurality of vias 10 are provided side by side on both sides of the first differential transmission line 4 and the second differential transmission line 5 in the X direction.

[0032] A third differential transmission path 6 and a fourth differential transmission path 7 are mounted on the surface of the second circuit board 3 on the Z2 direction side. The second circuit board 3 has a configuration similar to that of the first circuit board 2. Therefore, the third differential transmission path 6 and the fourth differential transmission path 7 are also configured as coplanar lines. The third differential transmission path 6 includes a pair of signal lines 6a. A differential transmission signal including a pair of signals having opposite phases is transmitted through the pair of signal lines 6a. The fourth differential transmission path 7 includes a pair of signal lines 7a. A differential transmission signal including a pair of signals having opposite phases is transmitted through the pair of signal lines 7a.

[0033] An end portion of the third differential transmission line 6 on the Y1 direction side and an end portion of the fourth differential transmission line 7 on the Y1 direction side are connected to the connector 1. An end portion of the third differential transmission line 6 on the Y2 direction side and an end portion of the fourth differential transmission line 7 on the Y2 direction side are connected to electronic components mounted on the second circuit board 3. These electronic components exchange differential transmission signals with the first circuit board 2. Note that FIG. 1 shows a portion of the second circuit board 3 including the edge on the Y1 direction side, and omits the portion of the second circuit board 3 on the Y2 direction side.

[0034] The connector 1 connects the first differential transmission line 4 and the third differential transmission line 6 to each other, and together with the first differential transmission line 4 and the third differential transmission line 6, constitute a line through which a differential transmission signal is transmitted. The connector 1 also connects the second differential transmission line 5 and the fourth differential transmission line 7 to each other, and together with the second differential transmission line 5 and the fourth differential transmission line 7, constitute a line through which a differential transmission signal is transmitted.

[0035] The connector 1 extends along the Z direction. The connector 1 has a first end 1a on the Z2 direction side and a second end 1b on the Z1 direction side. The first end 1a is connected to the first differential transmission path 4 and the second differential transmission path 5 of the first circuit board 2. The second end 1b is connected to the third differential transmission path 6 and the fourth differential transmission path 7 of the second circuit board 3.

[0036] The connector 1 includes a plug 12 and a socket 14. The plug 12 is provided on the first end 1a side (the first circuit board 2 side). The socket 14 is provided on the second end 1b side (the second circuit board 3 side). The plug 12 and the socket 14 are matable with each other. FIG. 1 shows a state in which the plug 12 and the socket 14 are mated. When the plug 12 and the socket 14 are mated with each other, the connector 1 connects the first differential transmission path 4 and the third differential transmission path 6 to each other, and also connects the second differential transmission path 5 and the fourth differential transmission path 7 to each other.

[0037] The plug 12 includes a plug housing 16 and a plurality of plug terminals 18. Note that a portion of the plug housing 16 is omitted in Fig. 1. The socket 14 includes a socket housing 20 and a plurality of socket terminals 22.

[0038] Fig. 2 is a diagram showing a portion of the plug 12 as viewed from the Y1 direction. Note that in Fig. 2, parts of the components are cut away for ease of understanding. The multiple plug terminals 18 are components with a rectangular cross section made of a conductor such as copper, and have a pin shape extending in the Z direction. As shown in Fig. 2, the multiple plug terminals 18 (eight in the illustrated example) are arranged along a predetermined arrangement direction (X direction). The eight plug terminals 18 are arranged at a constant pitch p.

[0039] As shown in FIG. 1 , the eight plug terminals 18 each have eight connection ends 18 a, eight contact pieces 18 b, and eight main body portions 18 c. FIG. 3 is a side view of the plug terminals 18 and the socket terminal 22. FIG. 3 illustrates the plug terminals 18 and the socket terminal 22, with other components omitted. As shown in FIG. 3 , the connection ends 18 a are provided at the end of each plug terminal 18 that is closer to the first end 1 a (Z2 direction side). The connection ends 18 a are connected to the first differential transmission path 4 or the second differential transmission path 5 of the first circuit board 2. The contact pieces 18 b are provided at the end of each plug terminal 18 that is closer to the socket 14 (Z1 direction side). The contact pieces 18 b are portions that contact the socket terminals 22 of the socket 14. The main body portion 18 c connects the connection ends 18 a and the contact pieces 18 b and is formed linearly along the Z direction.

[0040] Of the eight connection ends 18a, four connection ends 18a aligned in the X2 direction are connected to the first differential transmission path 4, and the remaining four connection ends 18a are connected to the second differential transmission path 5. More specifically, of the eight connection ends 18a, the second connection end 18a from the X2 direction and the third connection end 18a from the X2 direction are connected to a pair of signal lines 4a. Furthermore, of the eight connection ends 18a, the second connection end 18a from the X1 direction and the third connection end 18a from the X1 direction are connected to a pair of signal lines 5a. Of the eight connection ends 18a, the remaining connection ends 18a are connected to the ground conductor 8.

[0041] FIG. 4 is a diagram illustrating a portion of the plug 12 as viewed from the X1 direction. The plug housing 16 includes a housing main body 24, a first shielding member 26, and a second shielding member 27. The housing main body 24 is a member formed of an insulating material such as resin. The housing main body 24 holds a plurality of plug terminals 18 arranged along the arrangement direction. The housing main body 24 includes a tip portion 24a (connection side end), a base portion 24b (board side end), and an intermediate portion 24c. The base portion 24b is a member on the first end 1a side and holds a plurality of connection end portions 18a. The tip portion 24a is a member located on the Z1 direction side of the base portion 24b and holds a plurality of contact piece portions 18b. The tip portion 24a is a member that is fitted into the socket 14 (connected portion). The intermediate portion 24c is a member that connects the tip portion 24a and the base portion 24b and holds a plurality of main body portions 18c. 4 and 5, the intermediate portion 24c is indicated by a two-dot chain line, but is omitted from the other drawings for ease of understanding.

[0042] 1, 2, and 4, the first shielding member 26 and the second shielding member 27 are rectangular plate-shaped members extending along the X-Z plane. The first shielding member 26 and the second shielding member 27 are disposed opposite each other with the plurality of plug terminals 18 sandwiched therebetween. The first shielding member 26 is provided on the Y1 side of the plurality of plug terminals 18. The second shielding member 27 is provided on the Y2 side of the plurality of plug terminals 18. The first shielding member 26 and the second shielding member 27 are fixed to the intermediate portion 24c. The first shielding member 26 and the second shielding member 27 will be described later.

[0043] As described above, the socket 14 includes a socket housing 20 and a plurality of socket terminals 22. Like the plurality of plug terminals 18, the plurality of socket terminals 22 are members with a rectangular cross section made of a conductor such as copper, and have a pin shape extending in the Z direction. The plurality of socket terminals 22 (eight in the illustrated example) are arranged in the arrangement direction (X direction) at the same pitch p as the plug terminals 18.

[0044] As shown in Fig. 1, the eight socket terminals 22 have eight connection ends 22a, eight contact piece portions 22b, and eight main body portions 22c. As shown in Fig. 3, the connection end portions 22a are provided at the end portions of the socket terminals 22 that are closer to the second end portion 1b (Z1 direction side). The connection end portions 22a are connected to the third differential transmission path 6 or the fourth differential transmission path 7 of the second circuit board 3. The contact piece portions 22b are provided at the end portions of the socket terminals 22 that are closer to the plug 12 (Z2 direction side). The contact piece portions 22b are contact portions that come into contact with the plug terminals 18 of the plug 12.

[0045] The main body portion 22c connects the connection ends 22a and the contact piece portion 22b. Of the eight connection ends 22a, four connection ends 22a aligned on the X2 direction side are connected to the third differential transmission path 6, and the remaining four connection ends 22a are connected to the fourth differential transmission path 7. More specifically, of the eight connection ends 22a, the second connection end 22a from the X2 direction side and the third connection end 22a from the X2 direction side are connected to a pair of signal lines 6a. Furthermore, of the eight connection ends 22a, the second connection end 22a from the X1 direction side and the third connection end 22a from the X1 direction side are connected to a pair of signal lines 7a. Of the eight connection ends 22a, the remaining connection ends 22a are connected to ground conductors.

[0046] The socket housing 20 is a member formed of resin, etc. The socket housing 20 holds a plurality of socket terminals 22 arranged in an arrangement direction.

[0047] When the plug 12 and the socket 14 are mated, the eight contact pieces 18b and the eight contact pieces 22b come into contact with each other, as shown in Fig. 3. Therefore, when the plug 12 and the socket 14 are mated, the eight plug terminals 18 and the eight socket terminals 22 are electrically connected. As a result, the connector 1 connects the first differential transmission path 4 and the third differential transmission path 6 to each other, and also connects the second differential transmission path 5 and the fourth differential transmission path 7 to each other. Furthermore, the eight pairs of plug terminals 18 and socket terminals 22 that come into contact with each other constitute eight conductor lines that connect the differential transmission paths 4, 5 and the differential transmission paths 6, 7 to each other.

[0048] 2 , of the eight plug terminals 18, four plug terminals 18 aligned in the X2 direction are first lines T1 connecting the first differential transmission line 4 and the third differential transmission line 6, and the remaining four plug terminals 18 are second lines T2 connecting the second differential transmission line 5 and the fourth differential transmission line 7. Furthermore, a pair of terminals 18s1 included in the first line T1 is a signal line connecting the pair of signal lines 4a and the pair of signal lines 6a. A pair of terminals 18g1 included in the first line T1 is a ground line connected to the ground conductors 8 and 9. Similarly, a pair of terminals 18s2 included in the second line T2 is a signal line connecting the pair of signal lines 5a and the pair of signal lines 7a. A pair of terminals 18g2 included in the second line T2 is a ground line connected to the ground conductors 8 and 9.

[0049] [Regarding the Shielding Member] Figure 5 is a cross-sectional view taken along line V-V in Figure 4. As shown in Figures 4 and 5, the first shielding member 26 and the second shielding member 27 are fixed to outer surfaces 24c1 and 24c2 of the intermediate portion 24c of the housing main body 24. The intermediate portion 24c has a rectangular parallelepiped shape with each side aligned along the X, Y, and Z directions. The outer surface 24c1 is the surface of the intermediate portion 24c facing the Y1 direction. The outer surface 24c2 is the surface of the intermediate portion 24c facing the Y2 direction. The intermediate portion 24c has eight slots 24c3 that hold eight plug terminals 18.

[0050] As described above, the first shielding member 26 and the second shielding member 27 have a rectangular plate shape along the X-Z plane. The size of the first shielding member 26 is the same as the size of the second shielding member 27. The first shielding member 26 and the second shielding member 27 are provided between the tip portion 24a and the base portion 24b. Therefore, the first shielding member 26 and the second shielding member 27 are provided in a portion of the area between the first end 1a and the second end 1b of the connector 1. Furthermore, the X-direction dimensions of the first shielding member 26 and the second shielding member 27 are larger than the X-direction dimensions of the tip portion 24a and the base portion 24b.

[0051] The first shielding member 26 is fixed to an outer surface 24c1 of the intermediate portion 24c, and is disposed opposite the side surfaces of the eight plug terminals 18 (conductor lines) along the arrangement direction. The second shielding member 27 is fixed to an outer surface 24c2 of the intermediate portion 24c, and is disposed opposite the first shielding member 26 so as to sandwich the eight plug terminals 18. Therefore, the intermediate portion 24c is interposed between the first shielding member 26 and the eight plug terminals 18. Similarly, the intermediate portion 24c is interposed between the second shielding member 27 and the eight plug terminals 18. Therefore, the distance in the Y direction between the side surfaces of the eight plug terminals 18 and the first shielding member 26 is determined by the dimension of the intermediate portion 24c. The distance between the side surfaces of the eight plug terminals 18 and the second shielding member 27 is also determined by the dimension of the intermediate portion 24c. The first shielding member 26 and the second shielding member 27 may be provided integrally with the intermediate portion 24c (housing main body 24).

[0052] As shown in Fig. 5, the first shielding member 26 has a dielectric substrate 38, a periodic structure 30, and a ground conductor plate 32. The dielectric substrate 38 has a first surface 38a and a second surface 38b. The first surface 38a faces the eight plug terminals 18 and faces in the Y2 direction. The second surface 38b is the opposite surface to the first surface 38a and faces in the Y1 direction. The periodic structure 30 is provided on the first surface 38a. The ground conductor plate 32 is provided on the second surface 38b.

[0053] The second shielding member 27 also has a dielectric substrate 39, a periodic structure 34, and a ground conductor plate 36. The dielectric substrate 39 has a first surface 39a and a second surface 39b. The first surface 39a faces the eight plug terminals 18 and faces in the Y1 direction. The second surface 39b is the opposite surface to the first surface 39a and faces in the Y2 direction. The periodic structure 30 is provided on the first surface 39a. The ground conductor plate 32 is provided on the second surface 39b.

[0054] The second shielding member 27 has the same configuration as the first shielding member 26. Therefore, in the following description, the first shielding member 26 will be described.

[0055] Fig. 6 is a diagram of the first shielding member 26 as viewed from the Y2 direction, and is a diagram showing an example of the periodic structure 30. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. As shown in Fig. 7, the first shielding member 26 has a dielectric substrate 38, the periodic structure 30, and a ground conductor plate 32.

[0056] The dielectric substrate 38 is a rectangular rigid substrate. Examples of materials for the dielectric substrate 38 include polyimide resin, epoxy resin, PPE resin, and fluororesin. The ground conductor plate 32 is a conductor pattern mounted on the second surface 38b. The conductor pattern is made of a conductor such as copper foil. The ground conductor plate 32 is mounted so as to extend over the entire surface of the second surface 38b.

[0057] As shown in FIG. 6 , the periodic structure 30 includes a plurality of unit cells 42 periodically arranged on the first surface 38 a. In this embodiment, the unit cells 42 are arranged at equal intervals in the X and Z directions. In the periodic structure 30 of this embodiment, five unit cells 42 are arranged in the X direction and five unit cells 42 are arranged in the Z direction. Thus, the periodic structure 30 of this embodiment includes 25 unit cells 42. Each of the unit cells 42 has a square shape. Each unit cell 42 has a square-shaped land portion 42 a and a strip portion 42 b. The land portion 42 a and the strip portion 42 b are conductor patterns made of copper foil, nickel foil, or the like, mounted on the first surface 38 a. The land portion 42 a is arranged at the center of the unit cell 42. The strip portion 42 b is formed in a rectangular spiral shape, extending from the corner of the land portion 42 a and surrounding the periphery of the land portion 42 a.

[0058] The periodic structure 30 further includes a plurality of vias 44. The vias 44 penetrate the dielectric substrate 38 and connect the lands 42a of the unit cells 42 to the ground conductor plate 32. Each of the unit cells 42 included in the periodic structure 30 of this embodiment having the above configuration functions as a resonant element. That is, the strip portions 42b resonate with electromagnetic waves of a predetermined frequency band among waves incident on the periodic structure 30, and the strip portions 42b attenuate the electromagnetic waves of the predetermined frequency band. The frequency band in which the unit cells 42 can attenuate electromagnetic waves is determined primarily by the length of the strip portions 42b. The length of the strip portions 42b is set to approximately ¼ the wavelength of the electromagnetic waves to be attenuated. The length of the strip portions 42b can be determined by the widths w1, w2, and w3 and the spacings d1 and d2. The widths w1, w2, and w3 and the spacings d1 and d2 are the dimensions of each portion of the unit cell 42. The width w1 is the dimension of one side of the unit cell 42. The width w2 is the dimension of one side of the land portion 42a. The width w3 is the width dimension of the strip portion 42b. The spacing d1 is the distance between the strip portions 42b and between the strip portion 42b and the land portion 42a. The spacing d2 is the distance between the periphery of the unit cell 42 and the strip portion 42b.

[0059] The first shielding member 26 has the function of shielding electromagnetic waves radiated from the eight plug terminals 18 (multiple conductor lines) by means of a dielectric substrate 38, a periodic structure 30 (unit cell 42) that attenuates electromagnetic waves, and a ground conductor plate 32.

[0060] In the connector 1 of this embodiment, the first line T1 (the pair of terminals 18s1) and the second line (the pair of terminals 18s2) are adjacent to each other in the arrangement direction, which may cause crosstalk between the first line T1 and the second line T2, resulting in a deterioration in communication quality.

[0061] In contrast, in this embodiment, the first shielding member 26 and the second shielding member 27, which have the function of blocking electromagnetic waves, are disposed opposite the side surfaces of the eight plug terminals 18 that constitute the first line T1 and the second line T2, and therefore the first shielding member 26 and the second shielding member 27 can prevent electromagnetic waves radiated from the pair of terminals 18s1 and the pair of terminals 18s2 from circulating between the pair of terminals 18s1 and the pair of terminals 18s2. As a result, crosstalk occurring between the first line T1 and the second line T2 can be reduced.

[0062] Furthermore, in this embodiment, the second shielding member 27 is disposed opposite the first shielding member 26 so as to sandwich the eight plug terminals 18 that make up the first line T1 and the second line T2, so that electromagnetic waves that circulate between the pair of terminals 18s1 and the pair of terminals 18s2 can be suppressed from two directions, thereby more effectively reducing crosstalk.

[0063] In this embodiment, the first shielding member 26 and the second shielding member 27 are provided in a portion of the connector 1 between the first end 1a and the second end 1b. Crosstalk can occur significantly in a specific portion of the connector 1 between the first end 1a and the second end 1b. Therefore, by providing the first shielding member 26 and the second shielding member 27 in the specific portion where crosstalk occurs significantly, crosstalk can be effectively reduced without providing the first shielding member 26 and the second shielding member 27 over the entire area between the first end 1a and the second end 1b.

[0064] Furthermore, the first shielding member 26 and the second shielding member 27 may be provided at a position including a central portion between the first end 1 a and the second end 1 b. Crosstalk may occur significantly at a node of resonance that occurs in a conductor line including eight pairs of plug terminals 18 and socket terminals 22 provided between the first end 1 a and the second end 1 b. Therefore, by providing the first shielding member 26 and the second shielding member 27 so as to include the central portion, which may become a node of resonance, crosstalk can be effectively reduced without providing the first shielding member 26 and the second shielding member 27 throughout the entire region between the first end 1 a and the second end 1 b.

[0065] 5, the distance in the Y direction between the side surfaces of the eight plug terminals 18 and the first shielding member 26 is the same as the distance a between the side surfaces of the eight plug terminals 18 and the second shielding member 27. Here, this distance a and the pitch p of the eight plug terminals 18 may satisfy the following formula: 1 ≦ a / p ≦ 2

[0066] If a / p is less than 1, the first shielding member 26 and the second shielding member 27 may affect the eight plug terminals 18. If a / p is greater than 2, there is a risk that the effect of shielding the electromagnetic waves radiated from the eight plug terminals 18 may not be sufficient. By setting a / p to be between 1 and 2, it is possible to appropriately shield the electromagnetic waves radiated from the multiple conductor lines.

[0067] [Second Embodiment] Figure 8 is a diagram showing a portion of a plug 12 according to a second embodiment. This embodiment differs from the first embodiment in that the dimensions of the first shielding member 26 and the second shielding member 27 in the X direction are smaller than those of the first shielding member 26 and the second shielding member 27 of the first embodiment. Note that the first shielding member 26 is omitted from Figure 8 for ease of understanding.

[0068] In this embodiment, the dimensions of the first shielding member 26 in the X direction and the dimensions of the second shielding member 27 in the X direction are smaller than the dimensions of the tip portion 24a in the X direction and the dimensions of the base portion 24b in the X direction.

[0069] The periodic structures 30 of each of the first shielding member 26 and the second shielding member 27 have two unit cells 42 arranged in the X direction and five unit cells 42 arranged in the Z direction. Therefore, the periodic structures 30, 34 of this embodiment include ten unit cells 42. The periodic structures 30, 34 have a rectangular shape. The four sides of the first shielding member 26 (second shielding member 27) in the X direction and the four sides of the periodic structure 30 (periodic structure 34) in the X direction and the Z direction coincide with each other.

[0070] The first shielding member 26 has a pair of sides 26a and 26b extending along the longitudinal direction (Z direction). Similarly, the second shielding member 27 has a pair of sides 27a and 27b extending along the longitudinal direction.

[0071] When the first shielding member 26 is viewed from the front in the Y direction, the side 26a on the X2 side is located on a terminal 18g1 included in the first line T1. The terminal 18g1 where the side 26a is located is the terminal (first ground line) located at the end in the X direction of the pair of terminals 18g1 included in the first line T1. The side 26b on the X1 side is also located on a terminal 18g2 included in the second line T2. The terminal 18g2 where the side 26b is located is the terminal located at the end in the X direction of the pair of terminals 18g2 included in the second line T2.

[0072] Similarly, when the second shielding member 27 is viewed from the front in the Y direction, the side 27a of the second shielding member 27 is located on the terminal 18g1 located on the end side in the X direction. The side 27b of the second shielding member 27 is located on the terminal 18g2 located on the end side in the X direction.

[0073] Even in this case, the first shielding member 26 and the second shielding member 27 face at least the side surfaces of the pair of terminals 18s1 and the pair of terminals 18s2, and therefore the first shielding member 26 and the second shielding member 27 can suppress electromagnetic waves from passing between the pair of terminals 18s1 and the pair of terminals 18s2.

[0074] [Regarding the Third Embodiment] Fig. 9 is a diagram showing a portion of a plug 12 according to a third embodiment. This embodiment differs from the first embodiment in that the first shielding member 26 and the second shielding member 27 have portions where the periodic structures 30, 34 are not provided. Note that the first shielding member 26 is omitted from Fig. 9 for ease of understanding.

[0075] The first shielding member 26 has a pair of sides 26a and 26b extending along the longitudinal direction (Z direction). Similarly, the second shielding member 27 has a pair of sides 27a and 27b extending along the longitudinal direction.

[0076] When the first shielding member 26 is viewed from the front in the Y direction, the side 26a on the X2 side is aligned along an outer edge 18g11 of a terminal 18g1 included in the first line T1. The terminal 18g1 having the outer edge 18g11 is the terminal located at the end in the X direction of the pair of terminals 18g1 included in the first line T1. The side 26b on the X1 side is located closer to the X1 side than the second line T2.

[0077] Similarly, the side 27a of the second shielding member 27 is aligned along the outer edge 18g11 of the terminal 18g1 located on the X-direction end side when the second shielding member 27 is viewed from the front in the Y direction. The side 27b of the second shielding member 27 is located closer to the X1 direction than the second line T2.

[0078] In the periodic structures 30, 34 of the first shielding member 26 and the second shielding member 27 of this embodiment, two unit cells 42 are arranged in the X direction and five unit cells 42 are arranged in the Z direction. Therefore, the periodic structures 30, 34 of this embodiment include ten unit cells 42. The periodic structures 30, 34 have a rectangular shape. The periodic structures 30, 34 have a pair of structure sides 30a, 30b, 34a, 34b along the longitudinal direction (Z direction). The structure sides 30a, 34a are sides on the X2 direction side. The structure sides 30b, 34b are sides on the X1 direction side.

[0079] The structure side 30b (structure side 34b) coincides with the side 26b (side 27b) of the first shielding member 26 (second shielding member 27). On the other hand, the structure side 30a (structure side 34a) is located closer to the X1 direction than the side 26a (side 27a) of the first shielding member 26 (second shielding member 27). Therefore, the first surface 38a of the dielectric substrate 38 of the first shielding member 26 and the first surface 39a of the dielectric substrate 39 of the second shielding member 27 have regions 26n and 27n where the periodic structure 30 is not provided. The regions 26n and 27n include the dielectric substrates 38 and 39 and the ground conductor plates 32 and 36, but do not include the periodic structures 30 and 34.

[0080] In this embodiment, when the first shielding member 26 and the second shielding member 27 are viewed from the front in the Y direction, the structure side portions 30a and 34a are located closer to the pair of terminals 18s1 than the terminal 18g1 (first ground line) having the outer edge 18g11, and more specifically, are located between the pair of terminals 18s1. In this case, the periodic structures 30 and 34 are disposed opposite the side surface of at least one of the pair of terminals 18s1 (pair of signal lines), so that electromagnetic waves radiated from the one of the pair of terminals 18s1 are shielded by the periodic structures 30 and 34. This makes it possible to suppress electromagnetic waves from circumventing each other between the pair of terminals 18s1 and the pair of terminals 18s2.

[0081] In this embodiment, when the first shielding member 26 and the second shielding member 27 are viewed from the front in the Y direction, the structure side portions 30a, 34a only need to be located closer to the pair of terminals 18s1 than the terminal 18g1 having the outer edge 18g11, and if the structure side portion 30a is positioned opposite the side surface of the pair of terminals 18s1, the electromagnetic waves radiated from the pair of terminals 18s1 are shielded by the periodic structures 30, 34.

[0082] [Regarding the Fourth and Fifth Embodiments] Fig. 10 is a diagram showing a portion of the plug 12 according to the fourth and fifth embodiments. In the first embodiment, the plug 12 includes the first shielding member 26 and the second shielding member 27. However, it is sufficient for the plug 12 to include either the first shielding member 26 or the second shielding member 27.

[0083] (a) in Fig. 10 shows a portion of the plug 12 according to the fourth embodiment. The plug 12 of the fourth embodiment includes a first shielding member 26 but does not include a second shielding member 27. (b) in Fig. 10 shows a portion of the plug 12 according to the fifth embodiment. The plug 12 of the fifth embodiment includes a second shielding member 27 but does not include the first shielding member 26.

[0084] In these embodiments, the first shielding member 26 or the second shielding member 27 can also prevent electromagnetic waves radiated from a pair of terminals 18s1 and a pair of terminals 18s2 included in the eight plug terminals 18 from circling between the pair of terminals 18s1 and the pair of terminals 18s2, thereby reducing crosstalk.

[0085] [Regarding the Sixth, Seventh, and Eighth Embodiments] Figure 11 is a partial cross-sectional view of the plug 12 according to the sixth, seventh, and eighth embodiments. Figure 11 shows a cross section along the YZ plane. In the first embodiment, the first shielding member 26 and the second shielding member 27 of the plug 12 include a dielectric substrate 38 (39), a ground conductor plate 32 (36), a periodic structure 30 (34), and vias 44. However, the first shielding member 26 and the second shielding member 27 may have a configuration in which some of these components are omitted.

[0086] 11A is a partial cross-sectional view of the plug 12 according to the sixth embodiment. The first shielding member 26 and the second shielding member 27 of the sixth embodiment include a dielectric substrate 38 (39), a ground conductor plate 32 (36), and a periodic structure 30 (34), but do not include vias 44. Therefore, the land portion 42a and the strip portion 42b included in the periodic structure 30 (34) are not grounded.

[0087] (b) in Fig. 11 is a partial cross-sectional view of the plug 12 according to the seventh embodiment. The first shielding member 26 and the second shielding member 27 of the seventh embodiment include a dielectric substrate 38 (39) and a ground conductor plate 32 (36), but do not include a periodic structure 30 (34) or vias 44. (c) in Fig. 11 is a partial cross-sectional view of the plug 12 according to the eighth embodiment. The first shielding member 26 and the second shielding member 27 of the eighth embodiment are composed only of a ground conductor plate 32 (36), and do not include a dielectric substrate 38 (39), a periodic structure 30 (34), or vias 44.

[0088] Even in the above configuration, the first shielding member 26 and the second shielding member 27 include at least the grounding conductor plate 32 (36), so that it is possible to prevent the electromagnetic waves radiated from a pair of terminals 18s1 and a pair of terminals 18s2 included in the eight plug terminals 18 from circumventing each other.

[0089] [Regarding the ninth embodiment] Fig. 12 is a diagram showing a part of the plug 12 according to the ninth embodiment. Fig. 13 is a diagram showing a part of the plug 12 as viewed from the Y2 direction. Fig. 14 is a diagram showing the first shielding member 26 of the ninth embodiment as viewed from the Y2 direction, and is a diagram showing an example of the periodic structure 30.

[0090] In this embodiment, the distance H (see FIG. 1 ) between the first circuit board 2 and the second circuit board 3 is smaller than in the first embodiment. The present embodiment is identical to the first embodiment except for the distance H. Therefore, in this embodiment, the distance between the tip end 24 a and the base end 24 b is narrower than in the first embodiment. Therefore, the length of each of the eight main body portions 18 c of the eight plug terminals 18 is shorter than the length of each of the eight main body portions 18 c in the first embodiment.

[0091] 14, the length of the strip portion 42b is longer by two sides. The widths w2 and w3 and the spacing d1 are the same as those in the first embodiment. Therefore, the width w1, which is the dimension of one side of the unit cell 42 included in the periodic structure 30, is relatively larger than the width w1 of the unit cell 42 in the first embodiment. The length of the strip portion 42b can be extended or shortened depending on the dimensions of each part of the unit cell 42.

[0092] In the periodic structure 30 of the first shielding member 26 of this embodiment, five unit cells 42 are arranged in the X direction and four unit cells 42 are arranged in the Z direction. In addition, since the second shielding member 27 is arranged between the tip portion 24 a and the base portion 24 b, the dimension in the Z direction is half that of the first shielding member 26. In other words, in the periodic structure 30 of the second shielding member 27 of this embodiment, five unit cells 42 are arranged in the X direction and two unit cells 42 are arranged in the Z direction.

[0093] In this way, even if the size of the first shielding member 26 and the size of the second shielding member 27 are different, it is possible to prevent the electromagnetic waves radiated from some of the eight plug terminals 18 from circumventing each other.

[0094] [Others] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. For example, in the above embodiments, the connector 1 includes eight plug terminals 18 and eight socket terminals 22, but the connector 1 may include a greater number of plug terminals 18 and socket terminals 22.

[0095] In addition, in the above-described embodiments, the case where the unit cells 42 included in the periodic structure 30, 34 are the same size has been described as an example. However, the unit cells included in the periodic structure 30 may include a mixture of unit cells of different sizes. Furthermore, the unit cells included in the periodic structure 30, 34 may include a mixture of unit cells of the same size but with different lengths of the strip-like portion 42b or different spiral directions. Furthermore, the unit cells included in the periodic structure 30, 34 may include a mixture of unit cells 42 lacking a strip-like portion 42b. Furthermore, when the periodic structure 30, 34 includes a plurality of vias 44, the unit cells included in the periodic structure 30, 34 may include a mixture of unit cells connected to the vias 44 and unit cells not connected to the vias 44.

[0096] Furthermore, in the above-described embodiments, the first shielding member 26 and the second shielding member 27 each have a unit cell 42, and the first shielding member 26 and the second shielding member 27 each have a periodic structure 30, 34 each composed of a plurality of unit cells 42. However, the first shielding member 26 and the second shielding member 27 may each be configured to have one unit cell 42.

[0097] Furthermore, in the above embodiments, the plug 12 has the first shielding member 26 and the second shielding member 27, but the socket 14 may have the first shielding member 26 and the second shielding member 27, or both the plug 12 and the socket 14 may have the first shielding member 26 and the second shielding member 27. The scope of the present invention is defined by the claims, rather than the meaning described above, and is intended to include meanings equivalent to the claims and all modifications within the scope of the claims.

[0098] [Verification Test] Next, a description will be given of a verification test conducted on the above-described connector 1. In the verification test, a model was constructed for each of the following examples and comparative examples, and the characteristics of each of the examples and comparative examples were obtained by computer simulation using the model.

[0099] Example 1 The connector 1 described in the first embodiment was constructed as a model of Example 1. The constructed model also included a portion of the first circuit board 2 and a portion of the second circuit board 3. The portion of the first circuit board 2 in the constructed model was the same as the portion of the first circuit board 2 shown in FIG. 1. Therefore, in the model, both ends of the first differential transmission path 4 on the Y direction side and both ends of the second differential transmission path 5 on the Y direction side were located on both sides of the first circuit board 2 on the Y direction side. A portion of the second circuit board 3 in the constructed model was also the same as the portion of the second circuit board 3 shown in FIG. 1. Therefore, in the model, both ends of the third differential transmission path 6 on the Y direction side and both ends of the fourth differential transmission path 7 on the Y direction side were located on both sides of the second circuit board 3 on the Y direction side. The dimensions of the first shielding member 26, the second shielding member 27, and related components in Example 1 were set as follows. Dimension of first shielding member 26 in X direction (Z direction): 9 mm Width w1 ( FIG. 6 : dimension of one side of unit cell 42): 1.8 mm Width w2 ( FIG. 6 : dimension of one side of land portion 42 a): 0.5 mm Width w3 ( FIG. 6 : width dimension of strip-shaped portion 42 b): 0.1 mm Length L of strip-shaped portion 42 b: 14.4 mm Material of periodic structure: copper Spacing d1 ( FIG. 6 : distance between strip-shaped portions): 0.1 mm Spacing d2 ( FIG. 6 : distance between the periphery of unit cell 42 and strip-shaped portion 42 b): 0.05 mm Distance a between plug terminal 18 and periodic structure 30 (34) ( FIG. 5 ): 1 mm Pitch p of plug terminal 18 ( FIG. 2 ): 0.5 mm Width of plug terminal 18: 0.35 mm Spacing H ( FIG. 1 : distance between first circuit board 2 and second circuit board 3): 29 mm

[0100] Example 2 The connector 1 described in the second embodiment was constructed as a model of Example 2. Therefore, the dimension of the first shielding member 26 in the X direction was 3.6 mm, and the dimension of the first shielding member 26 in the Z direction was 9 mm.

[0101] Example 3: The connector 1 shown in the third embodiment was constructed as a model of Example 3. Example 4: The connector 1 shown in the fourth embodiment was constructed as a model of Example 4. Therefore, Example 4 includes the first shielding member 26 but does not include the second shielding member 27. Example 5: The connector 1 shown in the fifth embodiment was constructed as a model of Example 5. Therefore, Example 5 includes the second shielding member 27 but does not include the first shielding member 26. Example 6: The connector 1 shown in the sixth embodiment was constructed as a model of Example 6. Example 7: The connector 1 shown in the seventh embodiment was constructed as a model of Example 7. Example 8: The connector 1 shown in the eighth embodiment was constructed as a model of Example 8.

[0102] Example 9 The connector 1 shown in the ninth embodiment was constructed as a model for Example 9. Among the dimensions of the first shielding member 26, the second shielding member 27, and the related parts in Example 1, the following values ​​were set to different values. Items not listed below are the same as those in the first embodiment. X-direction dimension of first shielding member 26: 10.5 mm Z-direction dimension of first shielding member 26: 8.4 mm X-direction dimension of second shielding member 27: 4.2 mm Z-direction dimension of second shielding member 28: 8.4 mm Length L of strip-shaped portion 42b: 18.35 mm Spacing d1 (FIG. 6: spacing between strip-shaped portions): 0.1 mm Spacing d2 (FIG. 6: spacing between the periphery of unit cell 42 and strip-shaped portion 42b): 0.1 mm Distance a (FIG. 5) between plug terminal 18 and periodic structure 30 (34): 1 mm Pitch p of plug terminal 18 (FIG. 2): 0.5 mm Width of plug terminal 18: 0.35 mm Spacing H (FIG. 1: spacing between first circuit board 2 and second circuit board 3): 25 mm

[0103] Comparative Example 1 A model of Comparative Example 1 was constructed by removing the first shielding member 26 and the second shielding member 27 from Example 1.

[0104] Comparative Example 2 A model of Comparative Example 2 was constructed by removing the first shielding member 26 and the second shielding member 27 from Example 9.

[0105] Comparison between Example 1 and Comparative Example 1 The S parameters S21, S41, and S31 were calculated when the line end of the first differential transmission line 4 was defined as port 1, the line end of the third differential transmission line 6 was defined as port 2, the line end of the second differential transmission line 5 was defined as port 3, and the line end of the fourth differential transmission line 7 was defined as port 4.

[0106] FIG. 15 is a graph showing the frequency characteristics of S21 for Example 1 and Comparative Example 1. In FIG. 15, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S21. Also in FIG. 15, the solid line represents the graph for Example 1, and the dashed line represents the graph for Comparative Example 1. As shown in FIG. 15, no significant difference is observed between S21 for Example 1 and S21 for Comparative Example 1. S21 represents the pass characteristic of the input signal. Therefore, from this result, it can be confirmed that the first shielding member 26 and the second shielding member 27 do not affect the input signal.

[0107] FIG. 16 is a graph showing the frequency characteristics of S41 for Example 1 and Comparative Example 1. In FIG. 16, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. Also, in FIG. 16, the solid line represents the graph for Example 1, and the dashed line represents the graph for Comparative Example 1. The S parameter S41 indicates far-end crosstalk. As shown in FIG. 16, in Comparative Example 1, peaks appear near 3 GHz, 6 GHz, 9 GHz, 12 GHz, and 15 GHz. These peaks correspond to the resonant frequencies determined according to the line length of the connector 1. In contrast, in Example 1, each peak is suppressed, and the range of change with frequency is suppressed. As a result, Example 1 exhibits an overall reduction in crosstalk compared to Comparative Example 1. Furthermore, for example, when the target value of S41 for crosstalk reduction is set to -40 dB, the peak portion of S41 for Comparative Example 1 exceeds the target value in the range of 10 GHz or less. In contrast to this, in S41 of Example 1, the target value is met in the range of 10 GHz or less, and it is clear that crosstalk is reduced.

[0108] FIG. 17 is a graph showing the frequency characteristics of S31 for Example 1 and Comparative Example 1. In FIG. 17, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S31. Also, in FIG. 17, the solid line represents the graph for Example 1, and the dashed line represents the graph for Comparative Example 1. The S parameter S31 represents near-end crosstalk. As shown in FIG. 17, in Comparative Example 1, peaks appear in the near-end crosstalk as well, near 3 GHz, near 6 GHz, near 9 GHz, near 12 GHz, and near 15 GHz. In contrast, in Example 1, each peak is suppressed, and overall crosstalk reduction is observed compared to Comparative Example 1. Furthermore, when the target value of S31 for crosstalk reduction is set to −40 dB, the peak portion of S31 for Comparative Example 1 exceeds the target value in the range of 10 GHz or less. In contrast, in Example 1, the target value is met in the range of 10 GHz or less, and it can be seen that crosstalk is reduced.

[0109] FIG. 18 is a diagram showing an example of the electric field distribution in the X-Y plane in Comparative Example 1. FIG. 19 is a diagram showing an example of the electric field distribution in the X-Y plane in Example 1. The electric field distribution shown in FIG. 19 is the X-Y plane shown in FIG. 5, and is the electric field distribution in the portion where the first shielding member 26 and the second shielding member 27 are provided in Example 1. In FIG. 19, the periodic structure 30 and the ground conductor plate 32 of the first shielding member 26, and the periodic structure 34 and the ground conductor plate 36 of the second shielding member 27 are indicated by straight lines. The electric field distribution shown in FIG. 18 shows the electric field distribution at the same position as in Example 1. In FIGS. 18 and 19, the darker the color, the stronger the electric field, and the lighter the color, the weaker the electric field.

[0110] As shown in Fig. 18, among the eight plug terminals 18, there is a region where a strong electric field is present between terminal 18g1 of the first line T1 and terminal 18g2 of the second line T2, which are adjacent to each other. In contrast, Fig. 19 relating to Example 1 shows that the electric field strength is reduced in the region between terminal 18g1 and terminal 18g2. In other words, it can be seen that the coupling between terminal 18g1 and terminal 18g2 is reduced, and crosstalk is reduced.

[0111] FIG. 20 is a graph showing the frequency characteristics of S41 when the distance a (FIG. 5) of Example 1 is changed. In FIG. 20, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. In FIG. 20, the solid line represents the graph when the distance a is 1 mm, and the dashed line represents the graph when the distance a is 1.2 mm. Looking at FIG. 20, when the distance a is 1.2 mm, the peak near 3 GHz rises compared to when the distance a is 1 mm. This peak near 3 GHz exceeds the target value of -40 dB. Therefore, it can be seen that the distance a is preferably 1 mm or less.

[0112] FIG. 21 is a graph showing the frequency characteristics of S41 when the distance a of Example 1 is changed. In FIG. 21, the solid line shows the graph when the distance a is 0.4 mm, and the dashed line shows the graph when the distance a is 0.5 mm. Looking at FIG. 21, when the distance a is 0.4 mm, the peak near 3 GHz is higher than when the distance a is 0.5 mm. This peak near 3 GHz exceeds the target value of -40 dB. Therefore, it can be seen that the distance a is preferably 0.5 mm or more. The pitch p of Example 1 is 0.5 mm. Therefore, it can be seen that a / p is preferably 1 or more and 2 or less.

[0113] Fig. 22 is a graph showing the frequency characteristics of S41 when the periodic structures 30, 34 of Example 1 are formed from nickel. In Fig. 22, the dashed line shows the graph when nickel is used for the periodic structures, and the solid line shows the graph for Example 1. As shown in Fig. 22, even when the periodic structures 30, 34 are formed from nickel, S41 is below the target value of -40 dB in the range of 10 GHz or less, and it can be seen that crosstalk is reduced.

[0114] Regarding Example 2 Fig. 23 is a graph showing the frequency characteristics of S41 in Example 2. In Fig. 23, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. In Fig. 23, the solid line represents the graph for Example 2, and the dashed line represents the graph for Example 1. In Example 2 as well, S41 is below the target value of -40 dB in the range of 10 GHz or less, and it can be seen that crosstalk is reduced.

[0115] Regarding Example 3 Fig. 24 is a graph showing the frequency characteristics of S41 in Example 3. In Fig. 24, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. In Fig. 24, the dashed line represents the graph for Example 3, and the solid line represents the graph for Example 1. In Example 3 as well, S41 is below the target value of -40 dB in the range of 10 GHz or less, and it can be seen that crosstalk is reduced.

[0116] Regarding Examples 4 and 5: Fig. 25 is a graph showing the frequency characteristics of S41 for Examples 4 and 5. In Fig. 25, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. In Fig. 25, the dashed line represents the graph for Example 4, the two-dot chain line represents the graph for Example 5, and the solid line represents the graph for Example 1. In Examples 4 and 5, similar to Example 1, a reduction in crosstalk is observed overall. In particular, S41 is below the target value of -40 dB in the range of 10 GHz or less, indicating that crosstalk is reduced.

[0117] Regarding Examples 6, 7, and 8: Fig. 26 is a graph showing the frequency characteristics of S41 for Examples 6, 7, and 8. In Fig. 26, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. In Fig. 26, the dashed line represents the graph for Example 6, the two-dot chain line represents the graph for Example 7, the one-dot chain line represents the graph for Example 8, and the solid line represents the graph for Example 1. In Examples 6, 7, and 8 as well, S41 is below the target value of -40 dB in the range of 10 GHz or less, and it can be seen that crosstalk is reduced.

[0118] Regarding Example 9: FIG. 27 is a graph showing the frequency characteristics of S41 for Comparative Example 1 and Comparative Example 2. In FIG. 27, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. Also in FIG. 27, the dashed line represents the graph for Comparative Example 1, and the solid line represents the graph for Comparative Example 2. Also, FIG. 28 is a graph showing the frequency characteristics of S31 for Comparative Example 1 and Comparative Example 2. In FIG. 28, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S31. Also in FIG. 28, the dashed line represents the graph for Comparative Example 1, and the solid line represents the graph for Comparative Example 2.

[0119] The gap H (FIG. 1) in Comparative Example 2 is 4 mm shorter than the gap H in Comparative Example 1. Therefore, the line length of the connector 1 in Comparative Example 2 is 4 mm shorter than the line length of the connector 1 in Comparative Example 1.

[0120] The graphs of S41 and S31 show peaks corresponding to the resonant frequency determined according to the line length of the connector 1. From S41 and S31 of Comparative Example 2, it can be seen that the resonant frequency of Comparative Example 2 is higher than that of Comparative Example 1 due to the shortened line length of the connector 1.

[0121] FIG. 29 is a graph showing the frequency characteristics of S41 in Example 9. In FIG. 29, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S41. Also in FIG. 29, the dashed line represents the graph for Example 9, and the solid line represents the graph for Comparative Example 2. Also in FIG. 30, the horizontal axis represents the frequency of the transmission signal, and the vertical axis represents S31. Also in FIG. 30, the dashed line represents the graph for Example 9, and the solid line represents the graph for Comparative Example 2. In Example 9 as well, S41 and S31 are below the target value of −40 dB in the range of 10 GHz or less, and it can be seen that crosstalk is reduced.

[0122] Characteristics of the Periodic Structure Next, the characteristics of the periodic structure of Example 1 to attenuate electromagnetic waves in a predetermined frequency band will be described. Fig. 31 is a diagram for explaining an incident wave on the first shielding member 26 of Example 1. Fig. 31 shows a state in which an incident wave in TM (Transverse Magnetic) mode is incident on the periodic structure of the shielding member at an incident angle θ. Here, as shown in Fig. 31 , the reflection loss when an incident wave in TM mode is incident on the shielding member at an incident angle θ was obtained by computer simulation.

[0123] Fig. 32 is a graph showing the frequency characteristics of the reflection loss when an incident wave is made incident on the first shielding member 26 of Example 1. Fig. 32 shows the frequency characteristics of the reflection loss for incident angles of 10 degrees increments between 0 degrees and 80 degrees. As shown in Fig. 32, the reflection characteristics of the first shielding member 26 of Example 1 show a frequency band in which the reflected wave is significantly attenuated.

[0124] Fig. 33 is an enlarged view of the band near 4.74 GHz in Fig. 32. Fig. 34 is an enlarged view of the band near 11.4 GHz in Fig. 32. Fig. 35 is an enlarged view of the band near 17.5 GHz in Fig. 32.

[0125] The width w1, which is the dimension of one side of the unit cell 42 of the periodic structure 30 in Example 1, is 1.8 mm, and the length of the strip-shaped portion 42b is 14.4 mm. The resonant frequencies of the strip-shaped portion 42b in Example 1 are 4.74 GHz, 11.4 GHz, and 17.5 GHz. In other words, the reflection characteristics of the first shielding member 26 in Example 1 include a frequency band in which the reflected wave is significantly attenuated near the resonant frequency of the strip-shaped portion 42b.

[0126] As described above, it can be seen that the periodic structure 30 (unit cell 42) of Example 1 has the property of attenuating electromagnetic waves in a predetermined frequency band among incident waves, and functions as a resonant element.

[0127] Fig. 36 is a graph showing the frequency characteristics of the reflection loss when an incident wave is made incident on the first shielding member 26 of Example 9. Fig. 36 shows the frequency characteristics of the reflection loss for incident angles of 10 degrees increments between 0 degrees and 80 degrees. In Fig. 36 , as in Fig. 32 , the reflection characteristics of the first shielding member 26 of Example 9 show a frequency band in which the attenuation of the reflected wave is significant.

[0128] The width w1, which is the dimension of one side of the unit cell 42 of the periodic structure 30 of Example 9, is 2.1 mm, and the length of the strip-shaped portion 42b is 18.35 mm. The resonant frequencies of the strip-shaped portion 42b of Example 9 are 3.3 GHz, 8.75 GHz, and 14.3 GHz. The reflection characteristics of the first shielding member 26 of Example 9 also show a frequency band in which the reflected wave is significantly attenuated near the resonant frequency of the strip-shaped portion 42b.

[0129] The strip portion 42b of Example 9 is longer than the strip portion 42b of Example 1. Therefore, by adjusting the length of the strip portion 42b, the frequency band in which electromagnetic waves can be attenuated can be adjusted. Therefore, for example, the resonant frequency occurring between the first end 1a and the second end 1b of the connector 1 can be adjusted to be included in the frequency band in which electromagnetic waves can be attenuated by the periodic structure (unit cell 42). In other words, by appropriately designing each part, including the length of the strip portion 42b, the resonant frequency of the connector 1 can be included in the frequency band in which electromagnetic waves can be attenuated by the periodic structure.

[0130] REFERENCE SIGNS LIST 1 connector 1a first end 1b second end 2 first circuit board 3 second circuit board 4 first differential transmission path 4a signal line 5 second differential transmission path 5a signal line 6 third differential transmission path 6a signal line 7 fourth differential transmission path 7a signal line 8 ground conductor 9 ground conductor 10 via 12 plug 14 socket 16 plug housing 18 plug terminal 18a connection end 18b contact piece portion 18c main body portion 18g1 terminal 18g11 outer edge 18g2 terminal 18s1 terminal 18s2 terminal 20 socket housing 22 socket terminal 22a connection end 22b contact piece portion 22c main body portion 24 housing main body 24a tip portion (connection side end) 24b base portion (substrate side end) 24c Intermediate portion 24c1 Outer surface 24c2 Outer surface 24c3 Slot 26 First shielding member 26a Side portion 26b Side portion 26n Region 27 Second shielding member 27a Side portion 27b Side portion 27n Region 28 Second shielding member 30 Periodic structure 30a Structure side portion 30b Structure side portion 32 Ground conductor plate 34 Periodic structure 34a Structure side portion 34b Structure side portion 36 Ground conductor plate 38 Dielectric substrate 38a First surface 38b Second surface 39 Dielectric substrate 39a First surface 39b Second surface 42 Unit cell 42a Land portion 42b Strip portion 44 Via T1 First line T2 Second line a Distance d1 Spacing d2 Spacing H: Spacing p: Pitch w1: Width w2: Width w3: Width θ: Incident angle

Claims

1. A signal transmission line having a first end connected to a first differential transmission line and a second differential transmission line, comprising: a plurality of conductor lines having a plurality of connection ends connected to the first differential transmission line and the second differential transmission line at the first end; a holding section that holds the plurality of conductor lines in an arrangement direction; and a first shielding member that is arranged opposite a side surface of the plurality of conductor lines in the arrangement direction and that shields electromagnetic waves radiated from the plurality of conductor lines.

2. The signal transmission line according to claim 1, further comprising a second shielding member arranged opposite the first shielding member so as to sandwich the plurality of conductor lines, and which shields electromagnetic waves radiated from the plurality of conductor lines.

3. A signal transmission line according to claim 1 or claim 2, wherein the first shielding member is provided in a portion of the distance from the first end to a second end on the opposite side of the first end in the direction in which the plurality of conductor lines extend.

4. A signal transmission line as described in claim 1 or claim 2, wherein the first shielding member is provided at a position including the center between the first end and a second end on the opposite side of the first end in the direction in which the plurality of conductor lines extend.

5. The signal transmission line according to any one of claims 1 to 4, wherein the plurality of conductor lines include a pair of signal lines connected to the first differential transmission line and a pair of ground lines arranged on both sides of the pair of signal lines, a first ground line of the pair of ground lines is located at an end of the plurality of conductor lines in the arrangement direction, the first shielding member has a rectangular plate shape having a pair of sides along the direction in which the plurality of conductor lines extend, and when the first shielding member is viewed from the front, the side of the pair of sides located on the end side is located on the first ground line.

6. A signal transmission line according to any one of claims 1 to 5, wherein the first shielding member includes a rectangular ground conductor plate.

7. A signal transmission line according to any one of claims 1 to 5, wherein the first shielding member comprises: a rectangular dielectric substrate having a first surface facing the plurality of conductor lines and a second surface opposite the first surface; and a ground conductor plate laminated on the second surface.

8. The signal transmission line according to claim 7, wherein the first shielding member further has one or more unit cells including a predetermined conductor pattern provided on the first surface.

9. The signal transmission line according to claim 7, wherein the first shielding member further has a periodic structure formed by periodically arranging a plurality of unit cells, each including a predetermined conductor pattern, on the first surface.

10. The signal transmission line according to claim 9, wherein the periodic structure further includes a plurality of vias that penetrate the dielectric substrate and connect the plurality of unit cells to the ground conductor plate.

11. The signal transmission line according to claim 10, wherein the plurality of conductor lines include a pair of signal lines connected to the first differential transmission line and a pair of ground lines arranged on both sides of the pair of signal lines, a first ground line of the pair of ground lines is located at an end of the plurality of conductor lines in the arrangement direction, the periodic structure has a rectangular shape with a pair of structure sides along the longitudinal direction, and when the first shielding member is viewed from the front, the structure side on the end side of the pair of structure sides is located closer to the pair of signal lines than the first ground line.

12. The signal transmission line according to claim 11, wherein, when the first shielding member is viewed from the front, the side of the structure on the end side is located between the pair of signal lines.

13. The signal transmission line according to any one of claims 9 to 12, wherein the following formula is satisfied, where a is the distance between the side surfaces of the plurality of conductor lines and the periodic structure, and p is the pitch of the plurality of conductor lines in the arrangement direction: 1 ≦ a / p ≦ 2 14. A signal transmission line as claimed in any one of claims 8 to 13, wherein the predetermined conductor pattern included in the unit cell has a characteristic of attenuating electromagnetic waves of a predetermined frequency band among incident waves, and a resonance frequency occurring between the first end and a second end opposite the first end is included in the predetermined frequency band.

15. A connector having a board-side end to which first and second differential transmission paths provided on a board are connected, and a connection-side end to which a connected portion is connected, the connector comprising: a plurality of linear terminals having a plurality of connection ends connected to the first and second differential transmission paths at the board-side end, and having a plurality of contact piece portions at the connection-side end that can come into contact with terminals of the connected portion; a holding portion that holds the plurality of terminals in an array in a predetermined array direction; and a first shielding member that is arranged opposite side surfaces of the plurality of terminals in the array direction and that shields electromagnetic waves radiated from the plurality of terminals.

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