JP5019033B2 - Common mode current suppression EBG filter - Google Patents

Description

  The present invention relates to a filter using an EBG material for a connector on a printed circuit board, and to a filter structure that suppresses propagation of a high-frequency noise current generated inside the printed circuit board to a cable via the connector.

  With the development of technology in recent years, an electromagnetic band gap (hereinafter referred to as EBG) material has been developed, and has been proposed as a means for preventing electromagnetic interference between circuits due to unnecessary electromagnetic radiation from a high frequency circuit, for example. In a broad sense, an EBG material is a material or structure in which a dielectric or conductor has a two-dimensional or three-dimensional periodic structure, and suppresses or greatly attenuates the propagation of electromagnetic waves in a specific frequency band in two or three dimensions. Say.

  As one form of the EBG material, a high impedance surface (hereinafter referred to as HIS) is disclosed in Patent Document 1 and the like. FIG. 1 shows FIG. 2 shows a conventional HIS described in FIG. The HIS 1 has a structure in which thumbtack-like conductor elements 4 composed of conductor pieces 2 and conductor pillars 3 are periodically arranged on a ground plane, and each conductor element 4 is electrically connected to the ground plane 5. Yes. As the shape of the conductor piece 2, a regular hexagon as shown in FIG. 1 b, a square as shown in FIG.

  As shown in FIG. 2, the HIS of FIG. 1 has a distribution in which a series capacitance C between adjacent thumbtack-like conductors and a short-circuit inductance L formed by two thumbtack-like conductors and a ground plane are two-dimensionally arranged. It can be considered as a constant circuit, and in the vicinity of the resonance frequency of the resonance circuit composed of the inductance L and the capacitance C, the impedance is increased, the propagation of the surface current is suppressed, and the bandwidth in which the propagation is suppressed (band gap band) It is known from Patent Document 1 that the width is proportional to the reciprocal of C.

  That is, if the series capacitance C is increased or the short-circuit inductance L is increased, the band gap appears on the low frequency side. Therefore, in order to use HIS as a narrow bandwidth filter in a low frequency region without increasing one conductor element, several methods for increasing the series capacitance between conductor pieces have been disclosed.

  For example, FIG. In the method described in No. 12, a structure (interdigital structure) in which adjacent conductor pieces are engaged with each other is adopted as shown in FIG. The series capacitance C is increased by elongating the opposing sides of adjacent conductor pieces.

  Further, FIG. In the method described in FIG. 11, by mounting the chip capacitor 41 between adjacent conductor pieces as shown in FIG. 4, a capacitance that cannot be obtained by the method shown in FIG. 1 can be obtained.

  As another method, for example, Patent Documents 1 to 3 disclose a method for increasing the series capacitance between conductor pieces by increasing the number of conductor pieces to two layers, and FIG. ~ D. FIG. 5 a shows the FIG. 14a shows the method described in 14a. FIG. 5 b shows FIG. 2a shows the method described in 2a. FIG. 5 c shows the FIG. The method described in 4 is shown. FIG. 5d shows the FIG. 10 shows the method described in FIG. The principle of increasing the series capacity in these methods is the same, and is as follows.

  It is composed of three conductor layers, and the first, second and third conductor layers are formed in order from the top. The dielectric plate inserted between the first conductor layer and the second conductor layer is the first dielectric plate 16, and the second dielectric plate inserted between the second conductor layer and the third conductor layer is the second dielectric plate. The dielectric plate 26 is used. Two-dimensional periodic structures of the first conductor piece 12 and the second conductor piece 22 are formed in the conductor first layer and the conductor second layer, respectively. The first dielectric plate 16 between the first conductor layer and the second conductor layer is a thin dielectric plate. FIG. 6 shows a state in which the first conductor piece 12 and the second conductor piece 22 constituting the HIS by a conventional method of increasing the number of conductor pieces in two layers are projected from the upper surface. In the region 51 where the first conductor piece 12 and the adjacent second conductor piece 22 overlap, the two conductors oppose each other through the first dielectric plate 16 having a thin plate thickness, so that a series capacitance is formed. In FIG. 6, it corresponds to a region 51a where the first conductor piece 12a shown in the center of FIG. 6 and the second conductor piece 22a shown in the upper left adjacent to each other overlap. In FIGS. 5a to 5d, vias (conductor columns) for electrically connecting the first conductor piece 12 and the second conductor piece 22 and the ground plane 5 formed in the conductor third layer are shown. Although there is a slight difference, both have the same principle in that the capacitance value can be easily increased by increasing the area of the overlapping region 51.

  There are several examples in which the EBG material is applied as a countermeasure for the electromagnetic interference problem. For example, in Patent Document 3, an EBG material is used for a ground plane as a method for preventing interference between two antennas via a surface current.

  Moreover, in patent document 4, EBG material is used for a part of inner wall of a housing | casing. When various functions are integrated in the high-frequency circuit inside the housing, unnecessary electromagnetic radiation is generated in the housing, and signals between each function interfere with each other, adversely affecting the characteristics of the entire high-frequency circuit. There's a problem. By using the EBG material on the inner wall of the casing facing the high-frequency circuit, unnecessary electromagnetic radiation in the casing is prevented, and the characteristics of the high-frequency circuit do not change even if the inner wall of the casing is close to the high-frequency circuit. The housing can be downsized.

  One of the causes of electromagnetic interference problems that have become a problem in recent years is unnecessary electromagnetic radiation from cables. This unnecessary electromagnetic radiation is generated when high-frequency noise current generated inside the printed circuit board propagates to the cable via the connector. Conventionally, as a countermeasure against common mode noise of a cable, for example, a shield technique using a shield box that covers a printed circuit board to which the cable is connected, or attaching a connector having a shield metal cover to one end of the cable can be cited.

US6262495 B1 (FIG.1, 2a, 2b, 14a, 14b) US6483481 B1 (FIG. 2a) US69333895 B2 (FIG. 10, 11, 12) JP 2004-22587 A (FIG. 1)

  As a technique for suppressing the above-described unnecessary electromagnetic radiation, there is a problem that the conventionally used shielding technique is expensive to manufacture, and it is desirable to take measures within a printed circuit board that is a source of high-frequency noise.

  As a countermeasure in the printed circuit board, it is conceivable to use HIS on the ground plane around the connector connected to the cable. The printed circuit board shown in FIG. In order to realize the HIS described in 2 above, a conductor layer of a substrate having two or more conductor layers is made into a two-dimensional periodic array of conductor pieces 2, and another conductor layer separated by a dielectric plate 6 is grounded. A via may be used as the plane 5 and the conductor pillar 3 that electrically connects the conductor piece 2 and the ground plane 5.

  Here, in order to reduce the area occupied by the HIS functioning as a filter, FIG. The structure in which the series capacitance C is increased or the short-circuit inductance L is increased is preferable to the HIS described in 2. In particular, since the series capacitance C can be easily increased, when the HIS is used as a narrow bandwidth filter, a method of increasing the series capacitance C without applying the conductor piece 2 can be applied.

  As a method of increasing the series capacitance between the conductor pieces, for example, in the case of the interdigital structure shown in FIG. 3, in order to increase the series capacitance C by one digit or more as compared with the HIS structure of FIG. The length of the side may be increased by one digit or more. However, the longer the length of the opposite side, the larger the area occupied by the gap region 31 shown in FIG. Not suitable for miniaturization of 2.

  In addition, the method of mounting the chip capacitor 41 shown in FIG. 4 has a problem from the viewpoint of manufacturing cost and high-density mounting because it requires a large number of chip capacitors.

  In the method of FIGS. 5a and 5b, which is a method of increasing the series capacitance by two layers of conductor pieces, the first conductor piece 12 is connected to the ground plane 5 by the first via 13 and the second conductor piece 22 is connected to the ground plane 5 by the second via 23, respectively. Electrically connected. The cross-sectional layer configuration of the first conductor element 14 constituted by the first conductor piece 12 and the first via 13, the second conductor element 24 constituted by the second conductor piece 22 and the second via 23 is different.

  Similarly, in the method of FIGS. 5 c and d, which is a method of increasing the series capacitance by two layers of conductor pieces, only one of the first conductor piece 12 and the second conductor piece 22 is electrically connected by the ground plane 5 and the via 7. The remaining other conductor piece is in an electrically floating state without being electrically connected to the ground plane. The effect of the electrically floating structure is unknown.

An object of the present invention is to suppress unnecessary electromagnetic radiation emitted from the cable by propagating high-frequency noise current generated inside the printed circuit board to the cable via the connector, and at the same time, from the cable to the inside of the electronic device device. An object of the present invention is to provide a common mode current suppressing EBG filter using an EBG material that can suppress the propagation of high-frequency noise current to a printed circuit board and can be miniaturized to a size having no practical problem.
In particular, in the HIS that increases the series capacitance with two or more conductor pieces, the use of electrically floating conductors is not used, and the arrangement of conductor elements with the same cross-sectional layer configuration is devised, so that the propagation of high-frequency noise current is also efficient. An object of the present invention is to provide a common mode current suppression EBG filter that can be suppressed automatically.

  In the following, means for solving the problems will be described using the reference numerals used in the best modes and embodiments for carrying out the invention in parentheses. This reference numeral is added to clarify the correspondence between the description of the claims and the description of the best mode for carrying out the invention / example, and is described in the claims. It should not be used to interpret the technical scope of the invention.

The common mode current suppression filter of the present invention is
A high-impedance surface (101) (201) (301) (401) (501) (601), which is an electromagnetic gap material having a band gap that blocks surface current in a predetermined frequency band;
The high impedance surfaces (101) (201) (301) (401) (501) (601) are peripheral portions of the connector (108) on the printed circuit board (100) electrically connected to the cable (109). Is arranged.

In the common mode current suppression filter of the present invention,
The high impedance surfaces (101) (201) (301) (401) (501) (601) are:
Dielectric plates (116), (216), (316, 326), (416, 426, 436), (116), and (116) are formed on a plurality of conductive layers stacked and electrically connected. Conductor strips (112, 122) (212, 222) (312, 322, 332) (412, 422, 432, 442) (512, 522) (612, 622) and periodic on the ground plane (5) Step portions (120) (220) (320) (420) (520) (620) arranged in a line,
The conductor step part (120) (220) (320) (420) (520) (620) and the conductor pillar (103) which electrically connects the ground plane (5) are provided.

In the common mode current suppression filter of the present invention,
Between the adjacent conductor step portions (120) (220) (320) (420) (520) (620) is electrically non-contact,
When the periodic array of the conductor step portions (120) (220) (320) (420) (520) (620) is viewed from above, the adjacent conductor step portions (120) (220) (320) (420) ) (520) (620) The conductor piece of each of the plurality of conductor layers of the conductor stepped portions (120) (220) (320) (420) (520) (620) so that an overlapping region is generated. (112, 122) (212, 222) (312, 322, 332) (412, 422, 432, 442) (512, 522) (612, 622) are patterned.

In the common mode current suppression filter of the present invention,
When the periodic arrangement of the conductor step portions (120) (220) (320) (420) is viewed from above, the plurality of conductor layers of the conductor step portions (120) (220) (320) (420) When the first conductor layer, the second, ..., the last conductor layer from the top,
The conductor pieces (112) (212) (312 and 332) (412 and 432) formed in the odd-numbered conductor layers of the conductor step portions (120), (220), (320), and (420) are in the first direction. An L-shape having a first portion extending in a second direction, a second portion extending in a second direction perpendicular to the first direction, and a third portion connecting one end of the first and second portions. And
The conductor pieces (122) (222) (322) (422, 442) formed in the even-numbered conductor layers of the conductor step portions (120) (220) (320) (420) are arranged in the first direction. A first portion that extends, a second portion that extends in the second direction, and a third portion that connects one end of the first and second portions, and the L-shape is rotated 180 degrees. Yes,
The conductor pieces (112, 122) (212, 222) (312, 322, 332) (412, 422, each) of the plurality of conductor layers of the conductor step portions (120) (220) (320) (420) 432, 442) are patterned and electrically connected so as to overlap in their third part,
When the entire conductor step (120) (220) (320) (420) is viewed from above,
The conductor pieces (112, 122) (212, 222) (312, 322, 332) (412, 422, each) of the plurality of conductor layers of the conductor step portions (120) (220) (320) (420) 432, 442) overlap at its third part, forming a cross,
The conductor step portions (120) (220) (320) (420) formed with the cross shape are arranged in a square lattice pattern,
A region where the other end portions of the first portions of the adjacent conductor step portions (120) (220) (320) (420) overlap is provided, and a region where the other end portions of the second portions overlap is provided.

In the common mode current suppression filter of the present invention,
When the periodic arrangement of the conductor stepped portions (220) and (520) is viewed from the top, the plurality of conductor layers of the conductor stepped portions (220) and (520) are first, second, ... when the last conductor layer is used,
The conductor pieces (212) (512) formed in the odd-numbered conductor layers of the conductor stepped portions (220) (520) have a first portion extending in the first direction and a predetermined portion with respect to the first direction. A second portion extending in a second direction forming an angle, a third portion extending in a third direction forming an angle half of the predetermined angle with respect to the first direction, and the first, second and third portions thereof An arrow shape having a fourth portion connecting one end of the
The conductor pieces (222) and (522) formed in the even-numbered conductor layers of the conductor step portions (220) and (520) have a first portion extending in the first direction and a second portion extending in the second direction. And a third portion extending in the third direction, and a fourth portion connecting one end portions of the first, second and third portions, wherein the arrow shape is rotated 180 degrees. ,
The conductor strips (212, 222) (512, 522) of each of the plurality of conductor layers of the conductor stepped portions (220) (520) are patterned so as to overlap with each other in the fourth portion, and are electrically connected;
When the entire conductor step (220) (520) is viewed from above,
The conductor pieces (212, 222) (512, 522) of each of the plurality of conductor layers of the conductor stepped portions (220) (520) are overlapped at the fourth portion, thereby forming a * -shape,
The conductor step portions (220) and (520) in which the * shape is formed are arranged in a triangular lattice shape,
A region where the other end portions of the first portions of the adjacent conductor step portions (220) and (520) overlap is provided, a region where the other end portions of the second portions overlap is provided, and the other end of the third portion. A region where the parts overlap is provided.

In the common mode current suppression filter of the present invention,
When the periodic array of the conductor step portions (220) (320) (420) (520) is viewed from the top surface,
The conductor pieces (212, 222) (312, 322, 332) (412, 422, 432) of each of the plurality of conductor layers between the adjacent conductor step portions (220) (320) (420) (520). 442) The other end portions of the first and second portions of (512, 522) are wider than portions other than the other end portions.

In the common mode current suppression filter of the present invention,
When the periodic arrangement of the conductor stepped portions (620) is viewed from above, the plurality of conductor layers of the conductor stepped portion (620) are sequentially arranged from the top to the first, second,. When it is a conductor layer,
The conductor piece (612) formed in one of the odd-numbered and even-numbered conductor layers of the conductor stepped portion (620) has a first portion extending in the first direction and an angle θ1 with respect to the first direction. (Θ1 [degree] satisfies 45 <θ1 <90), a second portion extending in the first angular direction, and a third portion connecting the end portions of the first and second portions,
The conductor pieces (622) formed in the other conductor layer of the odd-numbered and even-numbered conductor steps (620) are angled with respect to the first portion extending in the first direction and the first direction. It has a second portion extending in the second angular direction that is the direction of θ2 (θ2 [degree] satisfies θ2 = 180−θ1), and a third portion that connects one end of the first and second portions. And
The conductor pieces (612, 622) of each of the plurality of conductor layers of the conductor stepped portion (620) are patterned so as to overlap with each other in the third portion, and electrically connected;
When the entire conductor step (620) is viewed from above,
The conductor pieces (612, 622) of each of the plurality of conductor layers of the conductor stepped portion (620) overlap with each other in the third portion, so that a straight portion extending in the first direction and a midpoint of the straight portion And a second portion extending in the first corner direction and the second corner direction is formed,
The conductor step portions (620) formed with the shape are arranged radially on a concentric circle,
A region where the other end portions of the first portions of the adjacent conductor step portions (620) overlap is provided, and a region where the other end portions of the second portions overlap is provided.

  A connector (HIS) (101) (201) (301) (401) (501) (601) connecting the cable (109) on the printed circuit board (100) to the high impedance plane (HIS) (101) (201) (301) where the band gap appears in a desired frequency band ( 108) Since the high frequency noise current flowing through the ground plane (5) generated in the printed circuit board (100) to the connector (108) is suppressed by being disposed in the peripheral portion, the high frequency noise current is It is possible to suppress unnecessary electromagnetic radiation from the cable (109) generated by propagating to the cable (109) via (108). At the same time, the propagation of the high frequency noise current transmitted to the cable (109) by the external unnecessary electromagnetic wave from the connector (108) to the ground plane (5) is suppressed, so that the operating characteristics of the internal circuit of the printed circuit board (100) It is possible to prevent the situation affected by the high frequency noise current flowing through the ground plane (5).

  Further, thin dielectric plates (116) (216) (316, 326) (416, 426, 436) used as constituent elements of HIS (101) (201) (301) (401) (501) (601) (116) Small conductor pieces (112, 122) (212, 222) (312, 322, 332) (412, 422, 432, 442) (512) 522) (612, 622) are electrically connected to the conductor step portions (120) (220) (320) (420) (520) (620) as HIS (101) (201) (301). ) (401) (501) By using it as a constituent element of (601), a structure that does not use electrically floating conductor pieces is possible.

  When the periodic arrangement of the conductor step portions (120) (220) (320) (420) (520) (620) is viewed from above, the adjacent conductor step portions (120) (220) (320) (420) ( 520) and (620) are made to overlap each other, thereby forming a dielectric plate having a thin series capacitance between adjacent conductor stepped portions (120) (220) (320) (420) (520) (620). 116), (216), (316, 326), (416, 426, 436), (116), and (116). ) (220) (320) (420) (520) (620) without increasing the size, the series capacitance between adjacent conductor step portions (120) (220) (320) (420) (520) (620) is increased. The HIS (101) (201) (301) (301) (401) (501) (601) HIS (101) (201) (301) (301) (401) (501) The area occupied by (601) can be reduced.

  When the entire conductor step portions (120), (220), (320), and (420) are viewed from above, the conductor step portions (120), (220), (320), and (420) are formed in a square lattice shape. By arranging them periodically, it is possible to easily provide a region where adjacent conductor step portions (120) (220) (320) (420) overlap.

  An area where adjacent conductor stepped portions (520) overlap each other by arranging the * -shaped conductor stepped portions (520) in a triangular lattice pattern when viewed from the upper surface of the entire conductor stepped portion (520). Can be easily provided.

  When the entire conductor stepped portion (620) is viewed from above, it has a shape having a straight portion extending in the first direction and a second portion extending in the first corner and the second corner direction from the midpoint of the straight portion, By arranging the shaped conductor step portions (620) in a circular arc shape, it is possible to easily provide a region where adjacent conductor step portions (620) overlap each other.

  Interlayer dielectric plates (116) (216) (316, 326) (416, 426, 436) (116) (116) of conductor stepped portions (120) (220) (320) (420) (520) (620) By using a material having a high dielectric constant, the capacitance between adjacent conductor step portions (120) (220) (320) (420) (520) (620) is increased.

  When there is no HIS, the high frequency noise current from the printed circuit board (100) is concentrated on the connector (108), and the high frequency noise current transmitted from the cable (109) is transmitted from the connector (108) to the printed circuit board (100). It is assumed that the conductor step portion (620) constituting the HIS (601) is concentrically arranged around the connector (108), so that the printed circuit board is concentrically arranged. The high-frequency noise current generated inside (100) is effectively suppressed from propagating to the connector (108), and at the same time, the high-frequency noise current transmitted to the cable (109) by an external unnecessary electromagnetic wave is transferred to the printed circuit board (100). It is also possible to efficiently suppress the propagation of.

  Next, the common mode current suppression EBG filter of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 7a is a top view showing the common mode current EBG filter according to the first embodiment of the present invention. FIG. 7b shows a cross-sectional view taken along the line AA 'of FIG. 7a.

  The common mode current EBG filter of the present invention has a high impedance surface (HIS) 101. The HIS 101 is arranged at the periphery of the connector 108 so as to surround the connector 108 on the printed circuit board 100. As shown in FIG. 7 b, assuming that the connector 108 on the printed circuit board 100 is electrically connected to the ground plane 5 of the printed circuit board 100 by the via 7, when the cable 109 is connected to the connector 108, The ground of the cable 109 is electrically connected to the ground plane 5. Here, when there is no HIS 101, the high-frequency noise current I generated inside the printed circuit board 100 flows through the ground plane and propagates to the cable 109 via the connector 108. Here, the HIS 101 in which a band gap appears in a desired frequency band is arranged in the periphery of the connector 108 as shown in FIGS. 7A and 7B, thereby suppressing the propagation of the high-frequency noise current I flowing through the ground plane to the connector 108. Therefore, propagation to the cable 109 is also suppressed. As a result, generation of unnecessary electromagnetic waves from the cable 109 can be suppressed. At the same time, when a high-frequency noise current I flows to the ground of the cable 109 due to external unnecessary electromagnetic waves, similarly, the HIS 101 suppresses propagation from the connector to the entire ground plane 5. Therefore, it is possible to prevent a situation where the operating characteristics of the internal circuit of the printed circuit board 100 are affected by the high frequency noise current flowing through the ground plane 5.

  FIG. 8a shows a cross-sectional view of the HIS 101 constituting the common mode current EBG filter according to the first embodiment of the present invention. FIG. 8 b shows an exploded cross-sectional view of each element constituting the HIS 101.

  As shown in FIG. 8b, the HIS 101 includes, as its constituent elements, conductor stepped portions 120 periodically arranged on the ground plane 5, and conductor pillars 103 connecting the conductor stepped portions 120 and the ground plane 5. It has. The conductor step portion 120 includes conductor pieces 112 and 122 that are formed on two conductor layers stacked in two layers with the dielectric plate 116 interposed therebetween and are electrically connected. In the example shown in FIG. 8a, if the conductor layers are the first, second, and third conductor layers in order from the top, the two-dimensional first conductor piece 112 and the second conductor piece 122 are formed on the conductor first layer and the conductor second layer, respectively. A periodic structure is formed. A thin first dielectric plate 116 is inserted between the first conductor piece 112 and the second conductor piece 122. The third conductor layer is a ground plane 5. By electrically connecting the first conductor piece 112 and the second conductor piece 122 by the step conductor connecting portion 121, the conductor step portion 120 shown in FIG. There is no electrical contact between adjacent conductor stepped portions 120. The conductor elements of the HIS 101 configured by the step conductor connecting portion 121 and the conductor pillar 103 are electrically connected, and the electrically floating conductor pieces are not used. Here, as shown in FIG. 8 c, the step conductor connecting portion 121 and the conductor pillar 103 can be integrated by the through via 117. This facilitates the manufacture of the HIS 101 on the printed circuit board.

  FIG. 9a shows a top view of the HIS 101 shown in FIGS. 8a and b. FIG. 9 b is a top view showing one conductor stepped portion 120. 9c and 9d show the layout of the periodic arrangement of the first conductor pieces 112 and the second conductor pieces 122, respectively.

  When the periodic arrangement of the conductor stepped portions 120 is viewed from above, the two conductor layers of the conductor stepped portion 120 are set as the first and second (final) conductor layers in order from the top. In this case, the first conductor piece 112 formed in the odd-numbered conductor layers of the conductor stepped portion 120 extends in the first direction extending in the first direction and in the second direction perpendicular to the first direction. It is L-shaped having a second part and a third part that connects one end of the first and second parts. The second conductor pieces 122 formed in the even numbered conductor layers of the conductor stepped portion 120 include a first portion extending in the first direction, a second portion extending in the second direction, and the first and second portions thereof. A third portion connecting one end portion, and the L-shape is a shape rotated by 180 degrees. The conductive pieces 112 and 122 of the two conductor layers of the conductor stepped portion 120 are electrically connected by patterning so that the third portions overlap each other. A layout that is axisymmetric to the layout shown in FIGS.

  When the entire conductor step portion 120 is viewed from above, the conductor pieces 112 and 122 of the two conductor layers of the conductor step portion 120 overlap at the third portion, whereby a cross shape is formed. The conductor step portions 120 formed with a cross shape are arranged in a square lattice pattern. A region 151 where the other ends of the first portions of adjacent conductor stepped portions 120 overlap is provided, and a region 151 where the other ends of the second portions overlap is provided. At this time, in the region 151 where the adjacent conductor stepped portions 120 overlap each other, the conductor pieces belonging to different conductor stepped portions are opposed to each other via the first dielectric plate 116 having a thin plate thickness. The adjacent conductor step portions are capacitively coupled with each other. In the present invention, the series capacitance C of the HIS 101 is equal to the series capacitance between the adjacent conductor step portions 120 without increasing the size of the conductor step portion as compared with the series capacitance C in the HIS composed of one layer of conductor pieces. It can be increased. If a high dielectric constant material is used as the first dielectric plate 116 having a thin plate thickness, an HIS having a larger series capacitance C can be configured.

(Second Embodiment)
In the second embodiment, descriptions overlapping with those in the first embodiment are omitted. In the second embodiment, in contrast to the above-described embodiment, the widths of the other end portions of the first and second portions of the adjacent conductor step portions are changed from those of the other portions, so that the adjacent conductor step portions 120 are adjacent to each other. It is possible to adjust the area of the region 151 where the two overlap.

  FIG. 10a shows a top view of the HIS 201 constituting the common mode current EBG filter according to the second embodiment of the present invention. FIG. 10 b is a top view showing one conductor stepped portion 220.

  The common mode current EBG filter of the present invention has a high impedance surface (HIS) 201. The HIS 201 is disposed at the periphery of the connector 108 so as to surround the connector 108 on the printed circuit board 100. The HIS 201 includes, as its constituent elements, conductor stepped portions 220 that are periodically arranged on the ground plane 5 and conductor pillars 103 that connect the conductor stepped portions 220 and the ground plane 5. The conductor step portion 220 includes conductor pieces 212 and 222 that are formed and electrically connected to two conductor layers laminated in two layers with the dielectric plate 216 interposed therebetween. When the conductor layers are the first, second, and third conductors in order from the top, the two-dimensional periodic structure of the first conductor piece 212 and the second conductor piece 222 is formed in the conductor first layer and the conductor second layer, respectively. A thin first dielectric plate 216 is inserted between the first conductor piece 212 and the second conductor piece 222. The third conductor layer is the ground plane 5, and the second dielectric plate 226 is inserted between the second conductor piece 222 and the ground plane 5.

  In the second embodiment, when the periodic arrangement of the conductor stepped portions 220 is viewed from the upper surface, the first and second portions of the small conductor pieces 212 and 222 of the two conductor layers of the adjacent conductor stepped portions 220 are adjacent to each other. The end portion is wider than the other portions other than the end portion. By increasing the width, it is possible to increase the value of the series capacitance C between adjacent conductor stepped portions 220 as compared to the HIS shown in FIG. 9a.

(Third embodiment)
In 3rd Embodiment, the description which overlaps with 1st, 2nd embodiment is abbreviate | omitted. In 3rd Embodiment, it is also possible to make the conductor piece which comprises a conductor level | step-difference part into 3 or more layers.

  FIGS. 11a and 11b respectively show a cross-sectional view and a top view of the HIS 301 constituting the common mode current EBG filter according to the third embodiment of the present invention in the case where the conductor piece has three layers.

  The common mode current EBG filter of the present invention has a high impedance surface (HIS) 301. The HIS 301 is disposed at the periphery of the connector 108 so as to surround the connector 108 on the printed circuit board 100. The HIS 301 includes, as its constituent elements, conductor stepped portions 320 that are periodically arranged on the ground plane 5 and conductor pillars 103 that connect the conductor stepped portions 320 and the ground plane 5. The conductor step portion 320 has conductor pieces 312, 322, and 332 that are formed and electrically connected to three conductor layers stacked in three layers with the dielectric plates 316 and 326 interposed therebetween. If the conductor layers are the first, second, third, and fourth conductor layers in order from the top, the first conductor piece 312, the second conductor piece 322, and the third conductor respectively in the conductor first layer, conductor second layer, and conductor third layer. A small piece 332 is formed. A thin first dielectric plate 316 is inserted between the first conductor piece 312 and the second conductor piece 322. A thin second dielectric plate 326 is inserted between the second conductor piece 322 and the third conductor piece 332. The fourth conductor layer is the ground plane 5, and a third dielectric plate 336 is inserted between the third conductor piece 332 and the ground plane 5.

  FIG. 11c shows a top view showing one of the conductor step portions 320 shown in FIG. 11a. FIG. 11 d shows the layout of the periodic arrangement of the first conductor pieces 312 and the third conductor pieces 332, respectively. FIG. 11 e shows the layout of the periodic array of second conductor pieces 322.

  When the periodic arrangement of the conductor stepped portions 320 is viewed from above, the three conductor layers of the conductor stepped portions 320 are set as the first, second, and third (final) conductor layers in order from the top. . In this case, the first conductor piece 312 and the third conductor piece 332 formed in the odd-numbered conductor layers of the conductor stepped portion 320 are in the direction perpendicular to the first direction and the first portion extending in the first direction. It is an L-shape having a second portion extending in a certain second direction and a third portion connecting one end portions of the first and second portions. The second conductor piece 322 formed in the even numbered conductor layer of the conductor stepped portion 320 includes a first portion extending in the first direction, a second portion extending in the second direction, and the first and second portions thereof. A third portion connecting one end portion, and the L-shape is a shape rotated by 180 degrees. The conductive small pieces 312, 322, and 332 of the three conductor layers of the conductor stepped portion 320 are electrically connected by patterning so as to overlap in the third portion.

  When the entire conductor step portion 320 is viewed from above, the conductor pieces 312, 322, and 332 of the three conductor layers of the conductor step portion 320 overlap each other at the third portion, thereby forming a cross shape. The conductor step portions 320 formed with a cross shape are arranged in a square lattice shape. A region 351 where the other ends of the first portions of the adjacent conductor stepped portions 320 overlap is provided, and a region 351 where the other ends of the second portions overlap is provided. At this time, in a region 351 where adjacent conductor stepped portions 320 overlap each other, the second conductor piece 322 faces not only the first conductor piece 312 but also the third conductor piece 332 through the second dielectric plate having a thin plate thickness. Because of the structure, it is possible to increase the value of the series capacitance C between adjacent conductor stepped portions 320 as compared to the HIS shown in FIG. 9a.

  Similarly, FIGS. 12a and 12b respectively show a cross-sectional view and a top view of the HIS 401 constituting the common mode current EBG filter according to the third embodiment of the present invention in the case where the conductor pieces have four layers.

  The common mode current EBG filter of the present invention has a high impedance surface (HIS) 401. The HIS 401 is disposed at the periphery of the connector 108 so as to surround the connector 108 on the printed circuit board 100. The HIS 401 includes, as its constituent elements, conductor stepped portions 420 periodically arranged on the ground plane 5 and conductor pillars 103 that connect the conductor stepped portions 420 and the ground plane 5. The conductor step portion 420 includes conductor pieces 412, 422, 432, and 442 that are formed and electrically connected to four conductor layers stacked in four layers with the dielectric plates 416, 426, and 436 interposed therebetween. Yes. When the conductor layers are the first, second, third, fourth, and fifth layers in order from the top, the first conductor piece 412 and the second conductor layer are respectively formed on the first conductor layer, the second conductor layer, the third conductor layer, and the fourth conductor layer. A conductor piece 422, a third conductor piece 432, and a fourth conductor piece 442 are formed. A thin first dielectric plate 416 is inserted between the first conductor piece 412 and the second conductor piece 422. A thin second dielectric plate 426 is inserted between the second conductor piece 422 and the third conductor piece 432. A thin third dielectric plate 436 is inserted between the third conductor piece 432 and the fourth conductor piece 442. The fifth conductor layer is the ground plane 5, and a fourth dielectric plate 446 is inserted between the fourth conductor piece 442 and the ground plane 5.

  FIG. 12 d shows the layout of the periodic arrangement of the first conductor pieces 412 and the third conductor pieces 432, respectively. FIG. 12e shows a layout of the periodic arrangement of the second conductor piece 422 and the fourth conductor piece 442. FIG.

  When the periodic arrangement of the conductor stepped portions 420 is viewed from the top, the four conductor layers of the conductor stepped portions 420 are first, second, third, fourth (final) in order from the top. Conductor layer. In this case, the first conductor piece 412 and the third conductor piece 432 formed on the odd-numbered conductor layers of the conductor stepped portion 420 include the first portion extending in the first direction and the direction perpendicular to the first direction. It is an L-shape having a second portion extending in a certain second direction and a third portion connecting one end portions of the first and second portions. The second conductor piece 422 and the fourth conductor piece 442 formed on the even-numbered conductor layer of the conductor stepped portion 420 include a first portion extending in the first direction, a second portion extending in the second direction, and a second portion thereof. 1 and the 3rd part which connects the one end part of a 2nd part, and said L shape is a shape rotated 180 degree | times. The conductive small pieces 412, 422, 432, 442 of the four conductor layers of the conductor stepped portion 420 are electrically connected by patterning so as to overlap in the third portion.

  When the entire conductor stepped portion 420 is viewed from the top surface, the conductor pieces 412, 422, 432, 442 of the four conductor layers of the conductor stepped portion 420 overlap each other in the third portion, thereby forming a cross shape. The conductor step portions 420 formed with a cross shape are arranged in a square lattice shape. A region 351 where the other ends of the first portions of the adjacent conductor stepped portions 420 overlap is provided, and a region 451 where the other ends of the second portions overlap is provided. At this time, in the region 451 where the adjacent conductor stepped portions 420 overlap each other, the area of the surface facing through the thin dielectric plate is further increased, so that it is adjacent to the HIS shown in FIGS. 9a and 11a. It is possible to increase the value of the series capacitance C between the conductor step portions 420 to be performed.

(Fourth embodiment)
In 4th Embodiment, the description which overlaps with 1st-3rd embodiment is abbreviate | omitted. In the fourth embodiment, when one conductor stepped portion is viewed from the top, the shape is not a cross but a * shape, and the conductor stepped portions can be arranged in a triangular lattice shape to configure the HIS. .

  FIG. 13a shows a top view of a HIS 501 constituting a common mode current EBG filter according to a fourth embodiment of the present invention. FIG. 13b shows one of the conductor step portions 520 shown in FIG. 13a.

  The common mode current EBG filter of the present invention has a high impedance surface (HIS) 501. The HIS 501 is arranged at the periphery of the connector 108 so as to surround the connector 108 on the printed circuit board 100. The HIS 501 includes, as its constituent elements, conductor step portions 520 that are periodically arranged on the ground plane 5 and conductor columns 103 that connect the conductor step portions 520 and the ground plane 5. The conductor step portion 520 includes conductor pieces 512 and 522 that are formed on two conductor layers laminated in two layers with the dielectric plate 516 interposed therebetween and are electrically connected. When the conductor layers are the first, second, and third conductors in order from the top, the two-dimensional periodic structures of the first conductor piece 512 and the second conductor piece 522 are formed in the conductor first layer and the conductor second layer, respectively. A thin first dielectric plate 116 is inserted between the first conductor piece 512 and the second conductor piece 522. The third conductor layer is the ground plane 5, and the second dielectric plate 126 is inserted between the second conductor piece 522 and the ground plane 5.

  When the periodic arrangement of the conductor step portions 520 is viewed from above, the two conductor layers of the conductor step portions 520 are set as the first and second (final) conductor layers in order from the top. In this case, the first conductor piece 512 formed in the odd-numbered conductor layer of the conductor stepped portion 520 has a first portion extending in the first direction and a second direction forming a predetermined angle with respect to the first direction. A second portion extending, a third portion extending in a third direction that forms a half of a predetermined angle with respect to the first direction, and a fourth portion connecting one end of the first, second, and third portions It is the arrow shape which has. The second conductor piece 522 formed in the even-numbered conductor layer of the conductor step portion 520 includes a first portion extending in the first direction, a second portion extending in the second direction, and a third portion extending in the third direction. And a fourth portion that connects one end portions of the first, second, and third portions, and the arrow shape is a shape rotated by 180 degrees. The conductive pieces 512 and 522 of the two conductor layers of the conductor stepped portion 520 are electrically connected by patterning so that the fourth portions overlap each other.

  When the entire conductor step portion 520 is viewed from the upper surface, the conductor pieces 512 and 522 of the two conductor layers of the conductor step portion 520 overlap each other in the fourth portion, whereby a * shape is formed. In particular, the * -shape improves symmetry and facilitates layout design. The conductor step portions 520 formed with the * shape are arranged in a triangular lattice shape. A region 551 where the other end portions of the first portions of the adjacent conductor step portions 520 overlap is provided, a region 551 where the other end portions of the second portions overlap, and a region 551 where the other end portions of the third portions overlap. Provided. Six overlapping regions 551 are formed for one conductor step portion 520.

(Fifth embodiment)
In 5th Embodiment, the description which overlaps with 1st-4th embodiment is abbreviate | omitted. In the fifth embodiment, the conductor step portions are periodically arranged in a square lattice shape or a triangular lattice shape in the above embodiment, but the conductor step portions are arranged concentrically around a certain point near the connector. Thus, the HIS can be configured.

  FIG. 14 a is a top view showing a common mode current EBG filter according to a fifth embodiment of the present invention. FIG. 14 b is a top view showing the HIS 601 used in the fifth embodiment of the present invention.

  The common mode current EBG filter of the present invention has a high impedance surface (HIS) 601. The HIS 601 is arranged at the periphery of the connector 108 so as to surround the connector 108 on the printed circuit board 100. The HIS 601 includes, as its constituent elements, conductor step portions 620 that are periodically arranged on the ground plane 5 and conductor columns 103 that connect the conductor step portions 620 and the ground plane 5. The conductor step portion 620 includes conductor pieces 612 and 622 that are formed and electrically connected to two conductor layers laminated in two layers with the dielectric plate 116 interposed therebetween. When the conductor layers are the first, second, and third conductors in order from the top, the two-dimensional periodic structure of the first conductor piece 612 and the second conductor piece 622 is formed in the conductor first layer and the conductor second layer, respectively. A thin first dielectric plate 116 is inserted between the first conductor piece 612 and the second conductor piece 622. The third conductor layer is the ground plane 5, and the second dielectric plate 126 is inserted between the second conductor piece 622 and the ground plane 5.

  When the periodic arrangement of the conductor step portions 620 is viewed from the upper surface, the two conductor layers of the conductor step portions 620 are set as the first and second (final) conductor layers in order from the top. In this case, one of the odd-numbered and even-numbered conductor layers of the conductor stepped portion 620 (for example, the first conductor piece 612 formed in the odd-numbered conductor layer) has a first portion extending in the first direction, The second portion extending in the first angular direction which is the direction of the angle θ1 (θ1 [degree] satisfies 45 <θ1 <90) with respect to the first direction is connected to one end of the first and second portions. And a third portion. The other of the odd-numbered and even-numbered conductor layers of the conductor stepped portion 620 (for example, the second conductor piece 622 formed in the even-numbered conductor layer) includes a first portion extending in the first direction, A second portion extending in a second angular direction that is an angle θ2 (θ2 [degree] satisfies θ2 = 180−θ1) with respect to the direction, and a first portion that connects one end of the first and second portions. 3 parts. By electrically patterning the conductor pieces 612 and 622 of each of the two conductor layers of the conductor stepped portion 120 so as to overlap each other in the third portion, they are electrically connected.

  When the conductor stepped portion 620 is viewed from the top, the conductor pieces 612 and 622 of the two conductor layers of the conductor stepped portion 620 overlap each other in the third portion, so that a straight portion extending in the first direction and a straight portion And a second portion extending in the first corner direction and the second corner direction from the midpoint. The conductor step portions 620 formed with the shape are arranged radially on a concentric circle. A region 651 where the other ends of the first portions of the adjacent conductor step portions 620 overlap is provided, and a region 651 where the other ends of the second portions overlap is provided.

  As described above, the HIS 601 is radially arranged on the printed circuit board 100 in a concentric circle around the connector 108. The reason for this will be described.

  The HIS 601 is close to the connector 108 and occupies a fan-shaped area centered on the connector 108. The conductor stepped portion 620 constituting the HIS 601 is provided on a concentric arc centering on a point 615 near the connector 108, and is arranged radially in the radial direction. According to the example of FIG. 14b, conductor step portions 620 are provided at equal angular intervals along arcs 617, 627, 637 that are arranged at equal intervals in the radial method. It has the same shape. The region 651 is provided by adjusting the L-shaped angles of the first conductor piece 612 and the second conductor piece 622 constituting the conductor stepped portion 620. When there is no HIS, a path where high-frequency noise current concentrates on the connector 108 from the printed circuit board 100, and high-frequency noise current transmitted from the cable 109 propagates radially from the connector 108 to the ground plane 5 of the printed circuit board 100. Therefore, the high-frequency noise current can be efficiently suppressed by arranging the conductor step portions 620 concentrically.

(effect)
The effect of the common mode current suppression EBG filter of the present invention will be described above.

  In the common mode current suppression EBG filter according to the first to fifth embodiments of the present invention, HIS (101) (201) (301) (401) (501) (601) in which a band gap appears in a desired frequency band is printed circuit. By disposing the peripheral portion of the connector 108 connected to the cable 109 on the substrate 100, propagation of the high frequency noise current flowing through the ground plane 5 generated inside the printed circuit board 100 to the connector 108 is suppressed. It is possible to suppress unnecessary electromagnetic radiation from the cable 109 generated by propagating to the cable 109 via the connector 108. At the same time, by suppressing the propagation of the high frequency noise current transmitted to the cable 109 by the unnecessary unnecessary electromagnetic wave from the connector 108 to the ground plane 5, the operating characteristic of the internal circuit of the printed circuit board 100 causes the high frequency noise current flowing through the ground plane 5. It is possible to prevent the situation that is affected by.

  In addition, the thin dielectric used as a component of the HIS (101) (201) (301) (401) (501) (601) in the common mode current suppression EBG filter according to the first to fifth embodiments of the present invention. Conductor pieces (112, 122) (212, 222) formed on a conductor layer formed by laminating two or more layers with the plates (116) (116) (316, 326) (416, 426, 436) (116) (116) interposed therebetween. ) (312, 322, 332) (412, 422, 432, 442) (512, 522) (612, 622) are electrically connected to the conductor step portions (120) (220) (320). By using (420) (520) (620) as a component of HIS (101) (201) (301) (401) (501) (601), Structure becomes possible without using a floated conductor pieces.

  In the common mode current suppression EBG filter according to the first to fifth embodiments of the present invention, when the periodic arrangement of the conductor step portions (120) (220) (320) (420) (520) (620) is viewed from above. Adjacent conductor step portions (120) (220) (320) (420) (520) (620) are created by creating a region where the adjacent conductor step portions (120) (220) (320) (420) (520) (620) overlap each other. (520) (620) The series capacitance between the thin dielectric plates (116), (116), (316, 326), (416, 426, 436), (116), and (116) on the opposing conductor surfaces Since it is configured, adjacent conductor stepped portions (1) without increasing the conductor stepped portions (120) (220) (320) (420) (520) (620) compared to the case of one conductor piece layer. 0) (220) (320) (420) (520) (620) can be increased in series capacity, and HIS (101) (201) (301) (401) (501) (601) is configured. Therefore, the size of the conductor element can be reduced, and the area occupied by the HIS (101) (201) (301) (401) (501) (601) can be reduced.

  In the common mode current suppression EBG filter according to the first to third embodiments of the present invention, when the entire conductor step portions (120), (220), (320), and (420) are viewed from above, a cross shape is formed. By arranging the step portions (120) (220) (320) (420) in a square lattice pattern, a region where adjacent conductor step portions (120) (220) (320) (420) overlap with each other can be easily provided. It becomes possible.

  In the common mode current-suppressing EBG filter according to the fourth embodiment of the present invention, when the entire conductor step portion (520) is viewed from the top, it has a * shape, and the * shape conductor step portion (520) is periodically arranged in a triangular lattice shape. By doing so, it is possible to easily provide a region where adjacent conductor step portions (520) overlap.

  In the common mode current-suppressing EBG filter according to the fifth embodiment of the present invention, when the entire conductor step portion (620) is viewed from above, a straight portion extending in the first direction, a first corner from the midpoint of the straight portion, and By forming a shape having a second portion extending in the second angular direction and periodically arranging the conductor step portions (620) of the shape in an arc shape, a region where adjacent conductor step portions (620) overlap each other can be easily provided. It becomes possible.

  In the common mode current suppression EBG filter according to the first to fifth embodiments of the present invention, the interlayer dielectric plates (116) (116) of the conductor step portions (120) (220) (320) (420) (520) (620). ) (316, 326) (416, 426, 436) (116) (116), by using a high dielectric constant material, adjacent conductor stepped portions (120) (220) (320) (420) (520) The capacity between (620) increases.

  In the common mode current suppressing EBG filter according to the fifth embodiment of the present invention, when there is no HIS, a path in which high frequency noise current is concentrated from the printed circuit board 100 to the connector 108 is taken, and the high frequency noise current transmitted from the cable 109 is the connector. 108 is assumed to propagate radially from the ground plane 5 of the printed circuit board 100 to the printed circuit board 100, the conductor step portions (620) constituting the HIS (601) are arranged concentrically around the connector 108. Propagation of the high frequency noise current generated inside the circuit board 100 to the connector 108 is efficiently suppressed, and at the same time, the high frequency noise current transmitted to the cable 109 due to an external unnecessary electromagnetic wave is propagated to the printed circuit board 100. Can also be effectively suppressed .

FIG. Sectional drawing of the conventional HIS described in 2a. FIG. 2 is a top view of a conventional HIS described in 2b. FIG. FIG. The top view of the conventional HIS described in 3a. FIG. The equivalent circuit diagram of the conventional HIS described in 2a. FIG. FIG. 13 is a plan view of an HIS using the interdigital structure described in FIG. FIG. 11 is an equivalent circuit diagram of the conventional HIS described in FIG. FIG. Sectional drawing of the conventional HIS described in 14a. FIG. Sectional drawing of the conventional HIS described in 2a. FIG. Sectional drawing of the conventional HIS described in FIG. FIG. 10 is a cross-sectional view of a conventional HIS described in FIG. The top view of the conventional HIS by the method of increasing a conductor piece to 2 layers. The top view which shows the common mode electric current EBG filter by 1st Embodiment of this invention. Sectional drawing in the A-A 'line of FIG. 7a. 1 is a cross-sectional view of a HIS 101 constituting a common mode current EBG filter according to a first embodiment of the present invention. FIG. 8B is an exploded cross-sectional view of each element constituting the HIS 101 shown in FIG. Sectional drawing which shows HIS101 comprised by integrating the step conductor connection part 121 and the conductor pillar 103 by the penetration via 117. FIG. 8 is a top view of the HIS 101 of the present invention shown in FIGS. The top view which shows one of the conductor level | step-difference parts 120 of FIG. 9a. The top view which shows the layout of the periodic arrangement | sequence of the 1st conductor piece 112. FIG. The top view which shows the layout of the periodic arrangement | sequence of the 2nd conductor small piece 122. FIG. The top view of HIS201 which comprises the common mode electric current EBG filter by 2nd Embodiment of this invention. FIG. 10B is a top view showing one of the conductor step portions 220 shown in FIG. 10A. Sectional drawing of HIS301 which comprises the common mode electric current EBG filter by 3rd Embodiment of this invention in case a conductor piece is made into 3 layers. The top view of HIS301 which comprises the common mode electric current EBG filter by 3rd Embodiment of this invention in case a conductor piece is made into 3 layers. FIG. 11B is a top view showing one of the conductor step portions 320 shown in FIG. 11A. The layout of the periodic arrangement of the first conductor pieces 312 and the third conductor pieces 332. The layout of the periodic arrangement of the second conductor pieces 322. Sectional drawing of HIS401 which comprises the common mode electric current EBG filter by 3rd Embodiment of this invention when a conductor piece is made into 4 layers. The top view of HIS401 which comprises the common mode electric current EBG filter by 3rd Embodiment of this invention in case a conductor piece is made into 4 layers. The top view which shows one of the conductor level | step-difference parts 420 of FIG. 12a. The layout of the periodic arrangement of the first conductor pieces 412 and the third conductor pieces 432. The layout of the periodic arrangement of the second conductor piece 422 and the fourth conductor piece 442. The top view of HIS501 which comprises the common mode electric current EBG filter by 4th Embodiment of this invention. The top view which shows one of the conductor level | step-difference parts 520 of FIG. 13a. The top view which shows the common mode electric current EBG filter by 5th Embodiment of this invention. The top view which shows HIS601 used in 5th Embodiment of this invention.

Explanation of symbols

1, 101, 201, 301, 401, 501, 601 HIS,
2 conductor pieces,
3, 103 conductor pillars,
4 conductor elements,
5 Ground plane,
6 dielectric plates,
7, 107 vias,
12, 12a, 112, 212, 312, 412, 512, 612 first conductor piece,
13 First via,
14 first conductor element,
16, 116, 316, 416 first dielectric plate,
22, 22a, 122, 222, 322, 422, 522, 622 second conductor piece,
23 Second via,
24 second conductor element,
26, 126, 226, 326, 426 second dielectric plate,
51, 51a, 151, 251, 351, 451, 551, 651 region,
31 gap area,
41 chip capacitors,
100 printed circuit board,
108 connectors,
109 cable,
117 through vias,
120, 220, 320, 420, 520, 620 conductor step,
121, 221, 321, 421, 521, 621 Step conductor connection part,
332, 432 third conductor piece,
336, 436 third dielectric plate,
442 fourth conductor piece,
446 fourth dielectric plate;
615, the center point of the arc,
617, 627, 637 arc,

Claims (9)

An electromagnetic gap material having a band gap that blocks surface current in a predetermined frequency band,
A ground plane,
A plurality of conductor portions periodically arranged on the ground plane,
Each of the plurality of conductor portions is
A conductor step portion having a plurality of conductor pieces stacked with a dielectric plate in between, and a connection portion for electrically connecting each of the plurality of conductor pieces;
A conductor column that electrically connects the conductor step portion and the ground plane;
The ground plane and the plurality of conductor portions are partially disposed in a peripheral portion of a connector on a printed circuit board that is electrically connected to a cable ,
Common mode current suppression filter high frequency noise currents generated within the printed circuit board is that to suppress the common mode current propagating through said connector to said cable. When the plurality of conductor pieces are the first and second layers in order from the top layer,
The first conductor piece in the first layer of the first conductor stepped portion and the second conductor piece in the first layer of the second conductor stepped portion adjacent to the first conductor stepped portion include the plurality of conductors from the ground plane. The height in the stacking direction of the small pieces is the same,
The third conductor piece of the second layer of the first conductor stepped portion and the fourth conductor piece of the second layer of the second conductor stepped portion have the same height from the ground plane with respect to the stacking direction,
The common mode current suppression filter according to claim 1, wherein the first conductor piece and the fourth conductor piece form an overlapping region in the stacking direction. The first conductor piece and the second conductor piece include a first portion extending in a first direction, a second portion extending in a second direction perpendicular to the first direction, and first and second portions thereof. An L-shape having a third portion connecting one end of the portion;
The third conductor piece and the fourth conductor piece include a first portion extending in the first direction, a second portion extending in the second direction, and a third portion connecting one end of the first and second portions. And the L-shape is a shape rotated by 180 degrees,
Each of the first conductor piece and the third conductor piece, and the second conductor piece and the fourth conductor piece are patterned so as to overlap each other at the third portion thereof, and have a cross shape when viewed from above. Formed,
The common mode current suppression filter according to claim 2, wherein the other end portion of the first portion of the first conductor piece and the other end portion of the first portion of the fourth conductor piece overlap with each other in the stacking direction. The common mode current suppression filter according to claim 3, wherein each of the plurality of conductor portions is arranged in a square lattice pattern on the ground plane. The first conductor piece and the second conductor piece include a first portion extending in a first direction, a second portion extending in a second direction forming a predetermined angle with respect to the first direction, and the first direction. An arrow shape having a third portion extending in a third direction that forms a half of the predetermined angle, and a fourth portion connecting one end of the first, second, and third portions;
The third conductor piece and the fourth conductor piece include a first portion extending in the first direction, a second portion extending in the second direction, a third portion extending in the third direction, and first, A fourth portion connecting one end of the second and third portions, and the arrow shape is a shape rotated by 180 degrees,
Each of the first conductor piece and the third conductor piece, and the second conductor piece and the fourth conductor piece are patterned so as to overlap with each other in the fourth portion, and when viewed from the top surface, it has a * shape. Formed,
The common mode current suppression filter according to claim 2, wherein the other end portion of the first portion of the first conductor piece and the other end portion of the first portion of the fourth conductor piece overlap with each other in the stacking direction. The common mode current suppression filter according to claim 5, wherein each of the plurality of conductor portions is arranged in a triangular lattice pattern on the ground plane. When the first portion of the first conductor piece and the first portion of the fourth conductor piece are viewed from above,
The other end portion of the first portion of the first conductor piece is wider than other portions other than the end portions,
The common mode current suppression filter according to any one of claims 3 to 6, wherein the other end portion of the first portion of the fourth conductor piece is wider than a portion other than the other end portion. The first conductor piece and the second conductor piece have a first portion extending in a first direction and a direction of an angle θ1 (θ1 [degree] satisfies 45 <θ1 <90) with respect to the first direction. A second portion extending in the first angular direction; and a third portion connecting one end of the first and second portions;
The third conductor piece and the fourth conductor piece have a first portion extending in the first direction and a direction of an angle θ2 (θ2 [degree] satisfies θ2 = 180−θ1) with respect to the first direction. A second portion extending in the second angular direction, and a third portion connecting one end of the first and second portions,
Each of the first conductor piece and the third conductor piece, and the second conductor piece and the fourth conductor piece are patterned so as to overlap each other in the third portion, and when viewed from above, the first conductor piece and the fourth conductor piece are Formed in a shape having a linear portion extending in the direction and a second portion extending in the first and second angular directions from the midpoint of the linear portion,
The common mode current suppression filter according to claim 2, wherein the other end portion of the first portion of the first conductor piece and the other end portion of the first portion of the fourth conductor piece overlap with each other in the stacking direction. The common mode current suppression filter according to claim 8, wherein each of the plurality of conductor portions is radially arranged on a concentric circle on the ground plane.

Images