JP2006148762A - Filter element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter element with an excellent attenuation characteristic at a high frequency. <P>SOLUTION: The filter element includes a coil part 5 cylindrically formed as a whole by winding a signal conductor 9 and a ground conductor 8 via belt-like insulators 7a, 7b in an overlapped state, an output part B of the signal conductor 9 connected to an external part is specified by its internal circumferential part and an input part A connected to an external part is specified by its outer circumferential part, a grounding part C of the grounding conductor 8 connected to an external part is specified by its outer circumferential part, and a sheet shaped auxiliary grounding conductor 10 is wounded into the coil part 5 in a way of opposing to the inner circumference part of the signal conductor 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spiral laminated filter element which is formed by winding a strip-shaped conductor on a strip-shaped insulator.

  As this kind of filter element, a filter element disclosed as a comparative example and an example in Japanese Patent No. 2826320 is known. This filter element is formed by winding a plurality of strip conductors (band conductors for energization and ground) around a magnetic or non-magnetic winding frame or air core via a dielectric sheet having a high dielectric constant. Functions as a noise filter (normal mode type noise filter). In this filter element, an inductance is formed between a pair of leads connected to a winding start portion and a winding end portion of a current-carrying band-shaped conductor, and the band-shaped conductive material for grounding is provided over the entire length of the current-carrying band-shaped conductor. A capacitance is distributed between the body and the body. Therefore, this filter element can realize excellent attenuation characteristics over a wide frequency band.

  Among them, the filter element (hereinafter also referred to as “filter”) disclosed as a comparative example is provided on a cylindrical winding portion and one end surface thereof as shown in FIG. The three leads are configured. In this case, the winding portion is formed by laminating a laminated body (see FIG. 2 in the same publication) in which a strip conductor and a ground strip conductor are overlapped via two dielectric layers a plurality of times around the rotating winding shaft. It is formed by winding. On the other hand, the first inner lead for input / output is connected to the vicinity of the inner end (left end in the figure) of the strip-shaped conductor. Further, the first outer lead for input / output is connected to the vicinity of the outer side of the strip-shaped conductor. Further, the grounding outer lead is connected to the vicinity of the outer end of the grounding strip-like conductor, shifted from the first outer lead by 1/2 turn around the winding axis.

  With this configuration, in this filter, the distance between the first outer lead and the grounding outer lead in a state where each conductor is expanded can be sufficiently narrowed, so that excellent attenuation characteristics can be realized. Further, in this filter, since the first outer lead and the outer ground lead can be positioned at a predetermined interval on a substantially straight line through the center of the winding shaft, the mass production is excellent with almost uniform and good attenuation characteristics. Can be realized. Further, as shown in FIG. 1 (B) in the same publication, this filter has a first outer lead and an outer grounding side while heating the cylindrical winding portion in a state where the winding shaft is removed. By pressing from the direction orthogonal to the wire connecting the lead leads, the same effect can be obtained even in a configuration in which the air core portion and the winding portion are deformed flat.

  On the other hand, as shown in FIG. 4 of the same publication, the filter element disclosed as an embodiment includes a cylindrical winding portion and three leads provided on one end face thereof, and also has an outer grounding side. The lead is arranged to be shifted by 1/2 turn around the winding axis with respect to the first outer lead (the first outer lead, the grounding outer lead, and the winding axis center are arranged on a straight line), Common to the filter element of the comparative example described above. On the other hand, the filter element disclosed as an example is different from the filter element of the comparative example described above in that the first inner lead is arranged with a shift of ¼ rotation about the winding axis with respect to the first outer lead. To do.

With this configuration, in the filter element disclosed as an example, the distance between the first outer lead and the outer ground lead can be sufficiently narrowed in a state where two conductors are expanded, and thus an excellent attenuation characteristic is realized. can do. Further, in this filter element, when the winding portion is deformed flat, the first inner lead can be positioned at substantially the same position as the winding shaft center. As a result, the winding shaft center, that is, the first inner lead is centered. As described above, the grounding outer lead and the first outer lead can be arranged symmetrically. Therefore, in order to obtain sufficient physical distances between the first outer lead and the first inner lead and between the first inner lead and the grounding outer lead, it is necessary to perform operations such as wiring and soldering. Short-circuiting can be effectively avoided. Therefore, the filter element can be easily attached to the printed circuit board.
Japanese Patent No. 2826320 (page 3-5, FIGS. 1, 2 and 4)

  However, the conventional filter element has the following problems. That is, as described above, in this filter element, an inductance is formed between a pair of leads (first outer lead and first inner lead) connected to the winding start portion and winding end portion of the conductive belt-like conductor. In addition, a capacitance is formed in a distributed constant with the grounding strip-shaped conductor over the entire length of the conductive strip-shaped conductor, thereby functioning as a filter. However, in this filter element, an inductance is formed between the winding start portion and the winding end portion of the grounding strip conductor in the same manner as the energizing strip conductor. It is grounded only by one grounding outer lead connected to one of the winding start portion and the winding end portion. Therefore, in this filter element, the ground-side potential in the capacitance formed in a distributed constant between the energizing strip conductor and the ground strip conductor is separated from the connection portion of the ground outer lead. And rises due to the inductance formed in the grounding strip conductor. As a result, this filter element has a problem that the attenuation characteristic deteriorates at a high frequency. The inventor of the present application uses the lead separated from the outer lead for grounding out of the pair of leads connected to the winding start part and winding end part of the conductive belt-like conductor as the output lead. I found that it appears prominently.

  The present invention has been made to solve the above-described problems, and a main object of the present invention is to provide a filter element having excellent attenuation characteristics at a high frequency.

  In order to achieve the above object, the filter element according to claim 1 is formed in a cylindrical shape as a whole by winding one band-shaped conductor and the other band-shaped conductor in a state of being overlapped via a band-shaped insulator. A first conductor connected to the outside is defined in the inner peripheral part and a second connected part connected to the outside is defined in the outer peripheral part; In the belt-shaped conductor, a third connection portion connected to the outside is defined in the outer peripheral portion, and the sheet-shaped conductor is disposed on the coil portion so as to face the inner peripheral portion of the one strip-shaped conductor. It is involved. Here, the “strip-shaped conductor” in this specification is not limited to a sheet-shaped conductor having a small thickness, but a conductor having a certain thickness, for example, a cross-sectional shape is round, oval, square, or trapezoid. It is meant to include a formed plate-like conductor having flexibility. In addition, the “inner peripheral part” refers to a part included in several turns at the beginning of winding in the strip-shaped conductor, and the “outer peripheral part” refers to a part included in several turns at the end of winding in the strip-shaped conductor.

  According to a second aspect of the present invention, there is provided a filter element comprising: a coil portion formed in a cylindrical shape as a whole by winding one strip-shaped conductor and the other strip-shaped conductor in a state of being overlapped via a strip-shaped insulator. The one band-shaped conductor has a first connection part connected to the outside defined in the outer peripheral part and a second connection part connected to the outside defined in the inner peripheral part, and the other band-shaped conductor Has a third connecting portion connected to the outside defined in the inner peripheral portion, and a sheet-like conductor is wound around the coil portion so as to face the outer peripheral portion of the one strip-shaped conductor. .

  According to a third aspect of the present invention, there is provided a filter element comprising: a coil portion formed in a tubular shape as a whole by winding a signal strip conductor and a ground strip conductor in a state of being overlapped via a strip insulator. The signal strip conductor has an output portion defined in an inner peripheral portion and an input portion defined in an outer peripheral portion, and the ground strip conductor has a ground portion defined in an outer peripheral portion, and the coil portion A sheet-like auxiliary grounding conductor is wound around the inner side of the signal strip-shaped conductor.

  According to a fourth aspect of the present invention, there is provided a filter element comprising: a coil portion formed in a tubular shape as a whole by winding a signal strip conductor and a ground strip conductor in a state of being overlapped via a strip insulator. The signal strip conductor has an input portion defined in an inner peripheral portion and an output portion defined in an outer peripheral portion, and the ground strip conductor has a ground portion defined in an inner peripheral portion, and the coil A sheet-like auxiliary grounding conductor is wound around the portion so as to face the outer peripheral portion of the signal strip-shaped conductor.

  The filter element according to claim 5 is the filter element according to claim 3 or 4, wherein the grounding part is defined on the opposite side of the input part across the central axis of the coil portion, and the output The part is defined on the opposite side to the input part across the central axis of the coil portion.

  The filter element according to claim 6 is the filter element according to claim 3 or 4, wherein the grounding part is defined on the opposite side of the input part across the central axis of the coil part, and the output The part is defined on the opposite side to the grounding part across the central axis of the coil portion.

  According to a seventh aspect of the present invention, there is provided a filter element comprising: a coil portion formed in a cylindrical shape as a whole by winding a pair of strip conductors and another strip conductor in a state of being overlapped with each other via a strip insulator. The pair of strip conductors has a first connection part connected to the outside defined in each inner peripheral part and a second connection part connected to the outside defined in each outer peripheral part, In the belt-shaped conductor, a third connection portion connected to the outside is defined in the outer peripheral portion, and the coil-shaped conductor is a sheet-shaped conductor so as to face the inner peripheral portions of the pair of strip-shaped conductors. Is involved.

  The filter element according to claim 8 includes a coil portion formed in a cylindrical shape as a whole by winding a pair of strip conductors and another strip conductor in a state of being overlapped via a strip insulator. The pair of strip conductors has a first connection part connected to the outside defined in each outer peripheral part and a second connection part connected to the outside defined in each inner peripheral part, In the belt-shaped conductor, a third connection portion connected to the outside is defined in the inner circumferential portion, and the coil-shaped conductor is a sheet-shaped conductor so as to face each outer circumferential portion of the pair of strip-shaped conductors. Is involved.

  The filter element according to claim 9 is a coil formed as a whole by winding a pair of signal strip conductors and a ground strip conductor in a state of being overlapped via a strip insulator. The pair of signal strip conductors has an output portion defined on each inner peripheral portion and an input portion defined on each outer peripheral portion, and the ground strip conductor is grounded on the outer peripheral portion. A portion is defined, and a sheet-like auxiliary grounding conductor is wound around the coil portion so as to face the inner peripheral portions of the pair of signal strip-shaped conductors.

  The filter element according to claim 10 is a coil formed in a cylindrical shape as a whole by winding a pair of signal strip conductors and a ground strip conductor in a state of being overlapped via a strip insulator. Each of the pair of signal strip conductors has an input portion defined at each inner peripheral portion and an output portion defined at each outer peripheral portion, and the ground strip conductor is disposed at the inner peripheral portion. A grounding portion is defined, and a sheet-like auxiliary grounding conductor is wound around the coil portion so as to face the outer peripheral portion of the pair of signal strip-shaped conductors.

  The filter element according to claim 11 is the filter element according to claim 9 or 10, wherein the grounding part is defined on the opposite side of the input part across the central axis of the coil part, Each output part is respectively defined on the opposite side to each input part across the central axis of the coil part.

  The filter element according to claim 12 is the filter element according to claim 9 or 10, wherein the grounding portion is defined on the opposite side with respect to each input portion across the central axis of the coil portion, Each output part is respectively defined on the opposite side to the grounding part across the central axis of the coil part.

  A filter element according to a thirteenth aspect is the filter element according to any one of the ninth to twelfth aspects, wherein the auxiliary grounding conductor is a pair so as to face the pair of signal strip conductors. Is provided.

  The filter element according to claim 14 is the filter element according to any one of claims 3 to 6 and 9 to 13, wherein the auxiliary grounding conductor is defined by the output portion of the signal strip-shaped conductor. The portion of the grounding strip-shaped conductor facing the inner peripheral portion or the outer peripheral portion is separated from other portions of the grounding strip-shaped conductor.

  The filter element according to claim 15 is the filter element according to any one of claims 1, 2, 7, and 8, wherein an output terminal is connected to the first connection part, and an input terminal is the second connection part. , A grounding terminal is connected to the third connecting portion, and an auxiliary grounding terminal is connected to the sheet-like conductor. Here, the “terminal” in the present specification means not only a rod-shaped conductor but also a flexible wiring cable and a flat conductor such as a metal foil.

  The filter element according to claim 16 is the filter element according to any one of claims 3 to 6 and 9 to 14, wherein an input terminal is connected to the input part, an output terminal is connected to the output part, A grounding terminal is connected to the grounding part, and an auxiliary grounding terminal is connected to the auxiliary grounding conductor.

  A filter element according to a seventeenth aspect is the filter element according to any one of the first to fifteenth aspects, wherein a magnetic body is disposed in a gap formed in a central portion of the coil portion.

  According to the filter element of the first aspect, one of the band-shaped conductors, the other band-shaped conductor, and the sheet-shaped conductor are wound through the band-shaped insulator to form a coil portion as a whole as a whole. A first connection part (for example, an output part) is defined on the inner peripheral part of the strip-shaped conductor, a second connection part (for example, an input part) is defined on the outer peripheral part, and a third connection part is defined on the outer peripheral part of the other strip-shaped conductor. (For example, a grounded part), and by winding the sheet-like conductor around the coil portion so as to face the inner circumference of one of the band-like conductors, the inner circumference of one of the band-like conductors and the sheet-like conductor In addition, a capacitance can be formed in a distributed manner between the two and the ground, and the capacitance can be grounded via a sheet-like conductor having a short overall length, that is, a potential increase due to an inductance is small. Therefore, according to this filter element, as a result of being able to satisfactorily bypass noise to the ground side through a capacitance formed between the sheet-like conductor at the inner peripheral portion of one band-like conductor, Even in a high frequency region (for example, a frequency region of 3 MHz or more), it is possible to maintain good attenuation characteristics with respect to normal mode noise.

  According to the filter element of the second aspect, the one band-shaped conductor, the other band-shaped conductor, and the sheet-shaped conductor are wound through the band-shaped insulator to form a coil portion as a whole, A first connection part (for example, an output part) is defined on the outer peripheral part of the strip-shaped conductor, a second connection part (for example, an input part) is defined on the inner peripheral part, and a third connection is made on the inner peripheral part of the other strip-shaped conductor. By defining a part (for example, a grounding part) and winding the sheet-shaped conductor around the coil part so as to face the outer peripheral part of one of the band-shaped conductors, In addition, a capacitance can be formed in a distributed constant between the two, and the capacitance can be grounded via a sheet-like conductor having a short total length, that is, a potential increase due to an inductance is small. For this reason, according to this filter element, the noise can be favorably bypassed to the ground side through the capacitance formed between the belt-shaped conductor and the sheet-shaped conductor at the outer periphery of one of the belt-shaped conductors. Even in a frequency domain (for example, a frequency domain of 3 MHz or higher), it is possible to maintain good attenuation characteristics with respect to normal mode noise.

  According to the filter element of the third aspect, the signal strip conductor, the ground strip conductor and the auxiliary ground conductor are wound through the strip insulator to form a coil portion as a whole as a signal. An output part is defined on the inner circumference of the signal strip conductor, an input part is defined on the outer periphery of the signal band conductor, a grounding area is defined on the outer periphery of the ground strip conductor, and a signal strip conductor By winding the auxiliary grounding conductor around the coil portion so as to face the inner peripheral portion of the conductor, a capacitance can be formed in a distributed constant between the inner peripheral portion of the signal strip conductor and the auxiliary grounding conductor. In addition, this capacitance can be grounded via an auxiliary grounding conductor having a short overall length, that is, a potential increase due to inductance being small. For this reason, according to this filter element, the noise can be satisfactorily bypassed to the ground side through the capacitance formed between the signal strip-shaped conductor and the auxiliary grounding conductor. Even in a high frequency region (for example, a frequency region of 3 MHz or more), it is possible to maintain good attenuation characteristics with respect to normal mode noise.

  According to the filter element of the fourth aspect, the signal strip conductor, the ground strip conductor and the auxiliary ground conductor are wound through the strip insulator to form a coil portion as a whole as a signal. An input part is defined on the inner periphery of the signal strip conductor, an output part is defined on the outer periphery of the signal strip conductor, a ground part is defined on the inner periphery of the signal strip conductor, and a signal strip conductor is defined. By winding the auxiliary grounding conductor around the coil part so as to face the outer peripheral part of the body, a capacitance can be formed in a distributed constant between the outer peripheral part of the signal strip-shaped conductor and the auxiliary grounding conductor, In addition, this capacitance can be grounded via an auxiliary grounding conductor having a short overall length, that is, a potential increase due to inductance being small. For this reason, according to this filter element, the noise can be satisfactorily bypassed to the ground side via the capacitance formed between the conductor for auxiliary grounding in the outer peripheral portion of the signal strip-shaped conductor, Even in a high frequency region (for example, a frequency region of 3 MHz or more), it is possible to maintain good attenuation characteristics with respect to normal mode noise.

  According to the filter element of claim 5, the grounding part is defined on the opposite side of the input part across the central axis of the coil part, and the opposite side of the input part across the central axis of the coil part By defining the output part in the above, it is possible to secure a large attenuation amount in a predetermined frequency band. As a result, a normal mode filter element having excellent attenuation characteristics can be realized.

  According to the filter element of claim 6, the grounding part is defined on the opposite side to the input part across the central axis of the coil part, and the opposite side to the grounding part across the central axis of the coil part By defining the output part in the above, it is possible to secure a large attenuation amount in a predetermined frequency band. As a result, a normal mode filter element having excellent attenuation characteristics can be realized.

  In each of the filter elements according to claims 7 and 8, for example, an output part is defined in the first connection part, an input part is defined in the second connection part, and a grounding part is defined in the third connection part. In other cases, common mode noise propagates simultaneously through both the path from the input part to the output part in one band conductor and the path from the input part to the output part in the other band conductor, Respectively flows into the strip-shaped conductors. For this reason, the pair of input portions, the pair of strip conductors, and the pair of output portions can be regarded as one input portion, one strip conductor, and one output portion, respectively, with respect to common mode noise. For this reason, according to each filter element of this 7th, 8th, so that each filter element of Claims 1-6 shows a favorable attenuation | damping characteristic with respect to normal mode noise regarding common mode noise. It functions to exhibit good attenuation characteristics in the same way as it functions. Therefore, according to each of the filter elements according to claims 7 and 8, since the attenuation characteristic with respect to the common mode noise can be satisfactorily maintained even in a high frequency region (for example, a frequency region of 3 MHz or more), an excellent attenuation characteristic is obtained. It is possible to realize a filter element for common mode having

  Moreover, in each filter element of Claim 9-12, a common mode noise is output from the path | route from the input site | part in one signal strip | belt conductor to an output site | part, and the input site | part in the other signal strip | belt conductor. It propagates through both the route to the part at the same time and flows into the corresponding grounding strip conductors. Therefore, the pair of input parts, the pair of signal strip conductors, and the pair of output parts are regarded as one input part, one signal strip conductor, and one output part, respectively, with respect to common mode noise. be able to. For this reason, according to each filter element of the ninth to twelfth aspects, with respect to the common mode noise, each of the filter elements according to the first to sixth aspects exhibits good attenuation characteristics with respect to the normal mode noise. It functions to exhibit good attenuation characteristics in the same way as it functions. Therefore, according to each filter element of Claims 9-12, since it can maintain the attenuation | damping characteristic with respect to common mode noise favorably also in a high frequency area | region (for example, frequency area | region more than 3 MHz), it was excellent in the attenuation | damping characteristic. It is possible to realize a filter element for common mode having

  Further, according to the filter element according to claim 13, each filter element according to claim 9 is a common mode filter element. By providing the auxiliary grounding conductor, the auxiliary grounding conductor can be formed with the minimum necessary conductor. Therefore, the filter element can be reduced in weight.

  According to the filter element of the fourteenth aspect, the portion of the grounding strip conductor facing the inner peripheral portion or the outer peripheral portion where the output portion of the signal strip conductor is defined is different from that of the ground strip conductor. By configuring the auxiliary grounding conductor separately from the part, the number of strip insulators can be minimized, so that the product cost can be reduced by reducing the number of parts, and the filter element can be further reduced. The weight can be reduced.

  According to the filter element of claim 15, the output terminal is connected to the first connection part, the input terminal is connected to the second connection part, the grounding terminal is connected to the third connection part, and the sheet shape By connecting the auxiliary grounding terminal to the conductor, the filter element can be easily mounted on a power supply device or the like using each terminal.

  According to the filter element of claim 16, the input terminal is connected to the input part, the output terminal is connected to the output part, the grounding terminal is connected to the ground part, and the auxiliary grounding terminal is connected to the auxiliary grounding conductor. By connecting the filter element, the filter element can be easily mounted on a power supply device or the like using each terminal.

  In addition, according to the filter element of the seventeenth aspect, since the magnetic material is disposed in the gap formed in the central portion of the coil portion, the degree of coupling between the grounding strip conductor and the signal strip conductor and the distributed inductance Since the value of can be improved, the attenuation characteristic can be improved.

  Hereinafter, the best mode of a filter element according to the present invention will be described with reference to the accompanying drawings.

(First best mode)
First, the filter element 1 according to this embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the filter element 1 includes an input terminal 2, an output terminal 3, ground terminals 4 and 11, a coil portion 5, and a columnar (columnar as an example) magnetic body (magnetic core) 6. Thus, it functions as a distributed constant type noise filter (low-pass normal mode filter).

  As shown in FIG. 3, the coil portion 5 includes, for example, strip-shaped insulators 7a, 7b, and 7c formed to have the same width, and a strip-shaped conductor for grounding that is formed narrower than the strip-shaped insulators 7a, 7b, and 7c. A body 8, a signal strip conductor 9, and an auxiliary grounding conductor 10 are provided. In this case, each of the strip-like insulators 7a, 7b, 7c is made of a material having dielectric properties and electrical insulation properties (polyimide, polyethylene, insulating paper, etc.). Moreover, each strip | belt-shaped insulator 7a, 7b is comprised by the same width | variety, the same length, and uniform thickness. A grounding strip conductor (hereinafter also referred to as “grounding conductor”) 8 is defined on one end side (winding end end side, in other words, the outermost peripheral portion) and connected to the outside (the present invention) The one end side of the grounding terminal 4 is electrically connected to the third connection portion (C) in FIG. Further, the grounding conductor 8 is overlaid on the strip insulator 7a so as to be positioned at the center in the width direction of the strip insulator 7a. The strip insulator 7b is overlaid on the strip insulator 7a so as to sandwich the grounding conductor 8 between the strip insulator 7a. On the other hand, the signal strip-shaped conductor 9 (hereinafter also referred to as “signal conductor”) is defined on one end side (winding end end side, in other words, the outermost peripheral portion) and is connected to the external input portion ( One end side of the input terminal 2 is electrically connected to the second connection portion A) of the present invention, and is connected to the outside as defined by the other end side (the winding start end side, in other words, the innermost peripheral portion). One end of the output terminal 3 is electrically connected to the output part (first connection part in the present invention) B. Further, the signal conductor 9 is overlaid on the strip insulator 7b so as to be positioned at the center in the width direction of the strip insulator 7b. Moreover, the grounding conductor 8 and the signal conductor 9 are formed to have the same width, the same length, and a uniform thickness as an example. The strip insulator 7c is set to be shorter than the other strip insulators 7a and 7b, and on the other end side (winding start end side) of the strip insulator 7b, the signal conductor 9 The other end side is overlapped with the belt-like insulator 7b. Here, the “innermost peripheral portion” refers to a portion included in one turn of the winding in the grounding conductor 8 or the signal conductor 9, and the “outermost peripheral portion” refers to the grounding conductor 8 or A portion included in one turn at the end of winding in the signal conductor 9. The auxiliary grounding conductor 10 is formed in a sheet shape (or a short strip shape) whose length is set shorter than the other conductors 8 and 9, and one end side of the grounding terminal 11 is electrically connected to the auxiliary grounding conductor 10. It is connected. Specifically, the auxiliary grounding conductor 10 is defined to have a length of 2 turns or less. Further, the auxiliary grounding conductor 10 is overlaid on the strip-like insulator 7c so as to be positioned at the center in the width direction of the strip-like insulator 7c. Further, the auxiliary grounding conductor 10 is, for example, formed to have the same width as the signal conductor 9 and a uniform thickness.

  The coil portion 5 includes the strip insulators 7a, 7b, 7c and the conductors 8, 9, 10 that are stacked on each other, as shown by arrows in FIG. As shown in FIG. 1 as a whole, the other end side (the right end side in the figure) is wound so that the grounding conductor 8 is wound outside the signal conductor 9. In addition, it is formed in a cylindrical shape (a cylindrical shape in which a gap H is formed at the center). Therefore, in this coil part 5, the auxiliary grounding conductor 10 is opposed to the other end side (innermost peripheral part) of the signal conductor 9 in which the output part B is defined, with the band-like insulator 7c interposed. is doing. In addition, each of the conductors 8, 9, and 10 is wound in a state of being insulated from each other because any one of the strip insulators 7a, 7b, and 7c is interposed therebetween. The magnetic core 6 is mounted in the gap H and disposed at the center of the coil portion 5.

  In this case, when the coil part 5 is viewed from one end face (upper end face in FIG. 1) side, the input part A of the signal conductor 9 is located on the outer peripheral part of the coil part 5 as shown in FIG. positioned. Further, as shown in FIG. 1, the input terminal 2 connected to the input portion A of the signal conductor 9 has an other end side from the outer peripheral side portion on one end face (upper end face in the figure) of the coil portion 5. Has been pulled out. For this reason, in the state which looked at the coil part 5 from the one end surface side, the input site | part A of the signal conductor 9 and the extraction | drawer site | part of the input terminal 2 correspond substantially. Therefore, in the following, the drawing portion of the input terminal 2 is also referred to as “drawing portion A”. On the other hand, when the coil part 5 is viewed from one end face (upper end face in FIG. 1) side, the output part B of the signal conductor 9 is located on the inner peripheral part of the coil part 5 as shown in FIG. positioned. Further, the output terminal 3 connected to the output part B of the signal conductor 9 is, as shown in FIG. 1, the other end from the inner peripheral part on one end face (the upper end face in the figure) of the coil portion 5. The side is pulled out. For this reason, in the state which looked at the coil part 5 from the one end surface side, the output site | part B of the signal conductor 9 and the extraction | drawer site | part of the output terminal 3 correspond substantially. Therefore, in the following, the extraction part of the output terminal 3 is also referred to as “extraction part B”. Here, the output part B of the signal conductor 9 (that is, the lead-out part of the output terminal 3) is, as shown in FIG. 2, the central axis O of the coil portion 5 and the input part A of the signal conductor 9 (that is, the input part). And on the imaginary plane L (hereinafter also referred to as “plane L”) including the terminal 2 (the drawing portion of the terminal 2), and is set on the opposite side of the input portion A across the central axis O (or the magnetic core 6). ing. The grounding portion C of the grounding conductor 8 is located at the outer peripheral side portion of the coil portion 5 as shown in FIG. 2 when the coil portion 5 is viewed from one end face (upper end face in FIG. 1) side. is doing. Further, as shown in FIG. 1, the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 is connected to the other end from the outer peripheral side part on one end face (upper end face in the figure) of the coil part 5. The side is pulled out. For this reason, when the coil portion 5 is viewed from one end face side, the grounding portion C of the grounding conductor 8 and the lead-out portion of the grounding terminal 4 substantially coincide. Therefore, hereinafter, the extraction portion of the grounding terminal 4 is also referred to as “extraction portion C”. Specifically, as shown in FIG. 2, the grounding portion C of the grounding terminal 4 is set on the plane L and opposite to the input portion A across the central axis O of the coil portion 5. ing. As shown in FIG. 1, the grounding terminal 11 is an inner peripheral portion of one end face (upper end face in the drawing) of the coil portion 5 and in the vicinity of the lead-out portion B (see FIG. 2) of the output terminal 3. The other end side is pulled out from. Here, the “drawer part” of the input terminal 2 or the like in this specification refers to a part on the surface of the coil part 5 from which the input terminal 2 or the like protrudes from the coil part 5. Therefore, the coil portion 5 is accommodated in a pot core (magnetic material) or the like, and the portion where the input terminal 2 or the like is pulled out from the pot core is different from the portion where the input terminal 2 or the like is pulled out from the coil portion 5. The part pulled out from the part 5 is the “drawing part” of the input terminal 2 or the like. Similarly, when connecting the input terminal 2 and the like drawn out from the coil unit 5 to the bobbin leg, the part drawn out from the coil unit 5 becomes the “draw-out part” of the input terminal 2 and the like. Therefore, it is not necessary to dispose the bobbin foot on the plane L, and the bobbin foot can be disposed at an arbitrary position.

  According to the filter element 1, the conductors 8, 9, 10 and the strip insulators 7 a, 7 b, 7 c are wound so that the grounding conductor 8 is outside the signal conductor 9. The coil part 5 is formed in a cylindrical shape, the output part B is defined at the innermost peripheral part of the signal conductor 9, and the input part A is defined at the outermost peripheral part of the signal conductor 9, A grounding portion C is defined on the outermost peripheral portion of 8, and the auxiliary grounding conductor 10 is wound around the coil portion 5 so as to face the innermost peripheral portion of the signal conductor 9. Capacitance can be formed in a distributed constant between the innermost peripheral portion and the auxiliary grounding conductor 10, and this capacitance is reduced via the auxiliary grounding conductor 10 having a short overall length, that is, a potential increase due to inductance is small. Can be grounded. For this reason, according to this filter element 1, the noise is grounded via the capacitance formed between the signal conductor 9 and the auxiliary grounding conductor 10 at the innermost peripheral portion where the output terminal 3 is connected. As a result, it is possible to satisfactorily maintain the attenuation characteristic even in a high frequency region (for example, a frequency region of 3 MHz or more). Further, since the positions of the input part A and the output part B of the signal conductor 9 and the position of the ground part C of the grounding conductor 8 are defined as described above, a large amount of attenuation can be obtained in a predetermined frequency band. As a result, a normal mode filter element having excellent attenuation characteristics can be realized.

(Second best mode)
Next, the configuration of the filter element 21 according to the present embodiment will be described with reference to FIGS. In addition, about the structure same as the filter element 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  As shown in FIG. 4, the filter element 21 includes an input terminal 2, an output terminal 3, grounding terminals 4 and 11, a coil unit 25, and a magnetic core 6, and is a distributed constant type noise filter (low frequency band). It functions as a pass-through normal mode filter.

  As shown in FIG. 6, the coil portion 25 includes strip-like insulators 7 a, 7 b, 7 c and conductors 8, 9, 10. In this case, the signal conductor 9 has one end side of the output terminal 3 electrically connected to the output portion B defined on one end side (the winding end end side, in other words, the outermost peripheral portion), and the other end side ( One end side of the input terminal 2 is electrically connected to the input portion A defined on the winding start end side (in other words, the innermost peripheral portion in other words). Further, the signal conductor 9 is overlaid on the strip insulator 7a so as to be positioned at the center in the width direction of the strip insulator 7a. The strip insulator 7c is configured such that one end side (winding end end side) of the signal conductor 9 is sandwiched between the strip insulator 7a on one end side (winding end end side) of the strip insulator 7a. It is piled up. The auxiliary grounding conductor 10 is overlaid on the strip-like insulator 7c so as to be positioned at the center in the width direction of the strip-like insulator 7c in a state where one end of the grounding terminal 11 is electrically connected. . The strip insulator 7b is overlaid on the strip insulators 7a and 7c so as to sandwich the signal conductor 9 and the auxiliary ground conductor 10 between the strip insulator 7a. The grounding conductor 8 has one end side of the grounding terminal 4 electrically connected to a grounding portion C defined on the other end side (winding start end side, in other words, also the innermost peripheral portion). The grounding conductor 8 is overlaid on the strip insulator 7b. That is, the conductors 8 and 9 are superimposed on the strip insulator 7a with the strip insulator 7b, the auxiliary grounding conductor 10 and the strip insulator 7c sandwiched therebetween.

  The coil portion 25 is formed by connecting each of the strip insulators 7a, 7b, 7c and the conductors 8, 9, 10 that are overlapped with each other in addition to the conductors 8, 9 as indicated by arrows in FIG. As shown in FIG. 4, by winding the end side (the left end side in the figure) so that the signal conductor 9 is on the outer side with respect to the grounding conductor 8, It is formed in a cylindrical shape in which a gap H is formed. Therefore, in this coil portion 25, the auxiliary grounding conductor 10 is opposed to one end side (outermost peripheral portion) of the signal conductor 9 in which the output portion B is defined, with the band-like insulator 7c interposed. Yes. In addition, each of the conductors 8, 9, and 10 is wound in a state of being insulated from each other because any one of the strip insulators 7a, 7b, and 7c is interposed therebetween. A magnetic core 6 is mounted in the gap H of the coil portion 25.

  In this case, the input part A of the signal conductor 9 is an inner peripheral part of the coil part 25 as shown in FIG. 5 when the coil part 25 is viewed from one end face (upper end face in FIG. 4). Is located. Further, as shown in FIG. 4, the input terminal 2 connected to the input part A of the signal conductor 9 has the other end from the inner peripheral part on one end face (the upper end face in the figure) of the coil portion 25. The side is pulled out. For this reason, in the state which looked at the coil part 25 from the one end surface side, the input site | part A of the signal conductor 9 and the extraction | drawer site | part of the input terminal 2 correspond substantially. Therefore, in the following, the drawing portion of the input terminal 2 is also referred to as “drawing portion A”. On the other hand, the output part B of the signal conductor 9 is located at the outer peripheral part of the coil part 25 as shown in FIG. 5 when the coil part 25 is viewed from one end face (upper end face in FIG. 4) side. is doing. Further, as shown in FIG. 4, the output terminal 3 connected to the output part B of the signal conductor 9 has an other end side from the outer peripheral part on one end face (the upper end face in the figure) of the coil portion 25. Has been pulled out. For this reason, in the state which looked at the coil part 25 from the one end surface side, the output site | part B of the signal conductor 9 and the extraction | drawer site | part of the output terminal 3 correspond substantially. Therefore, in the following, the extraction part of the output terminal 3 is also referred to as “extraction part B”. Here, the output part B of the signal conductor 9 (that is, the lead-out part of the output terminal 3) is, as shown in FIG. 5, the central axis O of the coil portion 25 and the input part A of the signal conductor 9 (that is, the input part). It is set on the plane L including the lead portion 2 of the terminal 2 and on the opposite side to the input portion A across the central axis O (or the magnetic core 6). Further, when the coil portion 25 is viewed from one end surface (upper end surface in FIG. 4), the ground portion C of the grounding conductor 8 is located on the inner peripheral portion of the coil portion 25 as shown in FIG. positioned. Further, as shown in FIG. 4, the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 is different from the inner peripheral part on one end face (upper end face in the figure) of the coil portion 25. The end side is pulled out. For this reason, when the coil portion 25 is viewed from one end face side, the grounding portion C of the grounding conductor 8 and the lead-out portion of the grounding terminal 4 substantially coincide. Therefore, hereinafter, the extraction portion of the grounding terminal 4 is also referred to as “extraction portion C”. Specifically, as shown in FIG. 5, the grounding portion C of the grounding terminal 4 is set on the plane L and opposite to the input portion A across the central axis O of the coil portion 25. ing. As shown in FIG. 4, the grounding terminal 11 is an outer peripheral part of one end face (upper end face in the figure) of the coil portion 25 and from the vicinity of the lead-out part B of the output terminal 3 (see FIG. 5). The other end is pulled out.

  According to this filter element 21, the conductors 8, 9, 10 and the strip insulators 7 a, 7 b, 7 c are wound so that the signal conductor 9 is outside the ground conductor 8. The coil portion 25 is formed in a cylindrical shape, the input portion A is defined on the innermost peripheral portion of the signal conductor 9, and the output portion B is defined on the outermost peripheral portion of the signal conductor 9. 8, the grounding portion C is defined on the innermost periphery of the signal conductor 8, and the auxiliary grounding conductor 10 is wound around the coil portion 25 so as to face the outermost periphery of the signal conductor 9. Capacitance can be formed in a distributed constant between the outermost peripheral portion and the auxiliary grounding conductor 10, and the capacitance is grounded via the auxiliary grounding conductor 10 having a short overall length, that is, a potential increase due to inductance is small. can do. For this reason, according to this filter element 21, noise is grounded through the capacitance formed between the signal conductor 9 and the auxiliary grounding conductor 10 at the outermost peripheral portion to which the output terminal 3 is connected. As a result, it is possible to maintain good attenuation characteristics even in a high frequency region (for example, a frequency region of 3 MHz or more). Further, since the positions of the input part A and the output part B of the signal conductor 9 and the position of the ground part C of the grounding conductor 8 are defined as described above, a large amount of attenuation can be obtained in a predetermined frequency band. As a result, a normal mode filter element having excellent attenuation characteristics can be realized.

(Third best mode)
Next, the filter element 31 according to the present embodiment will be described with reference to FIGS.

  First, the configuration of the filter element 31 will be described. Since the filter element 31 is configured to function as a common mode filter based on the filter element 1 that functions as a normal mode filter, many of the components are common to the components of the filter element 1. Therefore, the same components as those of the filter element 1 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 7, the filter element 31 includes a pair of input terminals 2a and 2b (hereinafter also referred to as “input terminal 2” when not distinguished from each other) and a pair of output terminals 3a and 3b (hereinafter referred to as “output terminals when not distinguished from each other). 3 ”), the grounding terminals 4 and 11, the coil portion 35, and the magnetic core 6, and functions as a distributed constant type common mode noise filter (low-pass filter).

  As shown in FIG. 8, the coil portion 35 includes strip-shaped insulators 7a, 7b, 7c, a grounding conductor 8, and a pair of signal conductors 9a, 9b (hereinafter referred to as “signal conductor 9” unless otherwise specified. And an auxiliary grounding conductor 10. In this case, the grounding conductor 8 is formed by connecting the grounding terminal 4 to the grounding portion C defined on one end side (the winding end end side, in other words, the outermost peripheral portion), and the strip-like insulator 7a. It is layered on top. The strip insulator 7b is overlapped on the strip insulator 7a so that the grounding conductor 8 is sandwiched between the strip insulator 7a. The signal conductors 9a and 9b are formed with the same width and uniform thickness as an example, and are overlapped in parallel on the strip-like insulator 7b so as not to contact each other. In addition, each signal conductor 9a, 9b is electrically connected to one end side of the input terminals 2a, 2b at the input portion A defined on one end side (the end of the winding end, in other words, the outermost peripheral portion). In addition to being connected, one end side of each of the output terminals 3a and 3b is electrically connected to an output portion B defined on the other end side (the winding start end side, in other words, also the innermost peripheral portion). That is, the conductors 8 and 9 are overlaid on the strip insulator 7a with the strip insulator 7b sandwiched between them. The band-shaped insulator 7c sandwiches the other end side (winding start end side) of each signal conductor 9 between the band-shaped insulator 7b on the other end side (winding start end side) of the band-shaped insulator 7b. It is piled up like this. The auxiliary grounding conductor 10 is connected to the grounding terminal 11 and overlapped on the strip-like insulator 7c so as to be positioned at the center in the width direction of the strip-like insulator 7c.

  The coil portion 35 includes the strip insulators 7a, 7b, 7c and the conductors 8, 9a, 9b, 10 stacked on each other as shown by arrows in FIG. , 9b, 10 by winding so that the other end side (the right end side in the figure) starts to be wound and the grounding conductor 8 is outside the signal conductors 9a, 9b. As shown in FIG. 7, it is formed in a cylindrical shape with a gap H formed in the center. Therefore, in this coil portion 35, the auxiliary grounding conductor 10 is connected to the other end side (the outermost side) of each of the signal conductors 9a and 9b in which the output part B is defined with the band-like insulator 7c interposed therebetween. (Inner perimeter). In addition, each of the conductors 8, 9, and 10 is wound in a state of being insulated from each other because any one of the strip insulators 7a, 7b, and 7c is interposed therebetween. A magnetic core 6 is mounted in the gap H of the coil portion 15.

  In this case, the input portion A of each signal conductor 9a, 9b has a coil portion 5 as shown in FIG. 2 when the coil portion 35 is viewed from one end surface (upper end surface in FIG. 7) side. Similarly, they are located on the outer peripheral side of the coil portion 35. Further, each input terminal 2 connected to the input part A of each signal conductor 9a, 9b is connected to one end face of the coil part 35 in the same manner as the coil part 5, as shown in FIG. The other end side is pulled out from the outer peripheral side portion of the upper end surface of the first end surface. For this reason, in a state where the coil part 35 is viewed from one end face side, the input part A of each signal conductor 9 and the lead-out part of each input terminal 2 are substantially the same as in the case of the coil part 5. . Further, the output part B of each of the signal conductors 9a and 9b and the grounding part C of the grounding conductor 8 are the same as in the case of the coil part 5, and the coil part 35 is viewed from one end face side. They are located at the positions shown in FIG. Further, each lead-out part of each output terminal 3 and grounding terminal 4 is also the same as the case of the coil part 5, and the output part of each signal conductor 9 in the state where the coil part 35 is viewed from one end face side. B substantially coincides with the grounding portion C of the grounding conductor 8. As shown in FIG. 7, the grounding terminal 11 is drawn out from the vicinity of the lead-out part B (see FIG. 2) of each output terminal 3a, 3b.

  According to this filter element 31, the path from which the common mode noise leads from the input terminal 2a (input part A) to the output terminal 3a (output part B) via the signal conductor 9a and the input terminal 2b (input part) A) is simultaneously propagated through the signal conductor 9b to the output terminal 3b (its output part B), and flows into the grounding conductors 8 and 10 together. Therefore, the pair of input terminals 2a and 2b (a pair of input parts A), the pair of signal conductors 9a and 9b, and the pair of output terminals 3a and 3b (a pair of output parts B) Each can be regarded as one input terminal 2 (one input part A), one signal conductor 9 and one output terminal 3 (one output part B). Therefore, the filter element 31 functions to exhibit a good attenuation characteristic with respect to the common mode noise in the same manner as the filter element 1 functions to exhibit a good attenuation characteristic with respect to the normal mode noise.

(4th best form)
Next, the filter element 41 according to the present embodiment will be described with reference to FIGS.

  First, the configuration of the filter element 41 will be described. The filter element 41 is configured to function as a common mode filter based on the filter element 21 that functions as a normal mode filter. For this reason, the filter element 41 includes many components in common with the filter element 21. Since the filter element 41 is configured to function as a common mode filter like the filter element 31, the filter element 41 includes many components in common with the filter element 31. Therefore, the same components as those of the filter element 21 and the filter element 31 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 9, the filter element 41 includes a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, ground terminals 4 and 11, a coil portion 45, and a magnetic core 6, and is distributed. Functions as a constant type common mode noise filter (low-pass filter).

  As shown in FIG. 10, the coil portion 45 includes strip-like insulators 7a, 7b, 7c, a grounding conductor 8, a pair of signal conductors 9a, 9b, and an auxiliary grounding conductor 10. In this case, each of the signal conductors 9a and 9b is electrically connected to the output portion B defined on one end side (winding end side) and the other end side (winding). The input terminals 2a and 2b are electrically connected to the input site A defined on the start end side, and are superimposed on the strip insulator 7a. Each of the signal conductors 9a and 9b is formed to have the same width as an example. The band-like insulator 7c has a band-like shape on one end side (winding end end side) of the band-like insulator 7a, on one end side (winding end end side, in other words, the outermost peripheral portion) of each signal conductor 9a, 9b. They are stacked so as to be sandwiched between the insulator 7a. The auxiliary grounding conductor 10 is overlaid on the strip insulator 7c so as to be positioned at the center in the width direction of the strip insulator 7c in a state where one end of the ground terminal 11 is electrically connected. Yes. The strip insulator 7b is overlaid on the strip insulators 7a and 7c so as to sandwich the signal conductors 9a and 9b and the auxiliary grounding conductor 10 with the strip insulator 7a. In the grounding conductor 8, one end side of the grounding terminal 4 is electrically connected to a grounding part C defined on the other end side (winding start end side). The grounding conductor 8 is overlaid on the strip insulator 7b. That is, each conductor 8, 9a, 9b is overlapped with the strip insulator 7a so as to sandwich the strip insulator 7b between the conductor 7a and the strip insulator 7a. That is, the conductors 8, 9a, 9b are overlapped with the strip-shaped insulator 7b, the auxiliary grounding conductor 10, and the strip-shaped insulator 7c sandwiched therebetween.

  The coil portion 45 includes the strip-like insulators 7a, 7b, 7c and the conductors 8, 9a, 9b, 10 stacked on each other as shown by arrows in FIG. 9b, the signal conductors 9a and 9b are wound around the grounding conductor 8 with the other end side thereof being started to be wound, and as shown in FIG. It is formed in a cylindrical shape with H formed. Therefore, in this coil portion 45, the auxiliary grounding conductor 10 is connected to one end side of each signal conductor 9a, 9b in which the output part B is defined (the outermost side) with the strip-like insulator 7c interposed therebetween. (Outer peripheral part). In addition, each of the conductors 8, 9, and 10 is wound in a state of being insulated from each other because any one of the strip insulators 7a, 7b, and 7c is interposed therebetween. A magnetic core 6 is mounted in the gap H of the coil portion 45.

  In this case, the input portion A of each of the signal conductors 9a and 9b includes the coil portion 25 and the coil portion 25 as shown in FIG. 5 when the coil portion 45 is viewed from one end face (upper end face in FIG. 9) side. Similarly, they are located on the inner peripheral side of the coil portion 45. Each input terminal 2 connected to the input portion A of each signal conductor 9a, 9b is connected to one end face of the coil portion 45 (as shown in FIG. The other end side is pulled out from the inner peripheral side portion of the upper end surface of the first end surface. For this reason, in the state where the coil part 45 is viewed from one end face side, the input part A of each signal conductor 9 and the lead-out part of each input terminal 2 are substantially the same as in the case of the coil part 25. . Further, the output part B of each of the signal conductors 9a and 9b and the grounding part C of the grounding conductor 8 are also in the state where the coil part 45 is viewed from one end face side, as in the case of the coil part 25. They are located at the positions shown in FIG. Further, each lead-out part of each output terminal 3 and grounding terminal 4 is also the same as in the case of the coil part 25, and the output part of each signal conductor 9 in a state where the coil part 45 is viewed from one end face side. B substantially coincides with the grounding portion C of the grounding conductor 8. As shown in FIG. 9, the grounding terminal 11 is drawn from the vicinity of the lead-out part B (see FIG. 5) of each output terminal 3a, 3b.

  According to this filter element 41, with respect to common mode noise, as with the filter element 31, a pair of input terminals 2a and 2b (a pair of input portions A), a pair of signal conductors 9a and 9b, and a pair of outputs. The terminals 3a and 3b (a pair of output parts B) are regarded as one input terminal 2 (one input part A), one signal conductor 9 and one output terminal 3 (one output part B), respectively. Can do. Accordingly, the filter element 41 functions so as to exhibit a good attenuation characteristic with respect to the common mode noise in the same manner as the filter element 21 functions to exhibit a good attenuation characteristic with respect to the normal mode noise.

  The present invention is not limited to the configuration described above. For example, in each of the filter elements 1 and 31 described above, as shown in FIGS. 3 and 8, the auxiliary grounding conductor 10 is located at a position where the signal conductor 9 (9a, 9b) is sandwiched between the grounding conductor 8. However, as shown by the broken line in the figure, the auxiliary grounding conductor 10 is disposed between the grounding conductor 8 and the signal conductor 9 (9a, 9b). It can also be adopted. On the other hand, in each of the filter elements 21 and 41 described above, as shown in FIGS. 6 and 10, the auxiliary grounding conductor 10 is disposed between the grounding conductor 8 and the signal conductor 9 (9a, 9b). However, as shown by a broken line in the figure, a configuration in which the auxiliary grounding conductor 10 is disposed at a position sandwiching the signal conductor 9 (9a, 9b) between the grounding conductor 8 is adopted. You can also

  3 and 8, the auxiliary grounding conductor 10 is arranged between the grounding conductor 8 and the signal conductors 9 (9a, 9b), as indicated by a broken line in FIGS. In each provided configuration, the auxiliary grounding conductor 10 is located on the front side of the grounding conductor 8 and overlaps with the grounding conductor 8 when viewed from the signal conductor 9 (9a, 9b). It is in. In this case, a capacitance is formed mainly in a distributed constant between the auxiliary grounding conductor 10 and the signal conductor 9 (9a, 9b), and the grounding conductor is located on the back side of the auxiliary grounding conductor 10. No capacitance is formed between the portion 8 and the signal conductor 9 (9a, 9b). That is, the portion of the grounding conductor 8 located on the back side of the auxiliary grounding conductor 10 when viewed from the signal conductor 9 (9a, 9b) hardly contributes to the function as a filter. Therefore, the filter element having each configuration in which the auxiliary grounding conductor 10 is disposed between the grounding conductor 8 and the signal conductor 9 (9a, 9b) is connected to the auxiliary grounding conductor from the grounding conductor 8. Even if the part located on the back side of 10 is omitted, the filter function is sufficiently exhibited. By the way, in this configuration, a portion of the grounding conductor 8 facing the portion (the innermost peripheral portion or the outermost peripheral portion) including the output portion B of the signal conductor 9 (9a, 9b) The structure is the same as the structure used as the auxiliary grounding conductor 10 separated (divided) from other parts. Next, the filter elements 51, 61, 71, 81 employing this configuration will be described in detail with reference to FIGS.

(5th best form)
First, the configuration of the filter element 51 will be described with reference to FIGS. Since the configuration of the filter element 51 is similar to the configuration of the filter element 1, the same configuration as the filter element 1 is denoted by the same reference numeral, and redundant description is omitted.

  As shown in FIG. 1, the filter element 51 includes an input terminal 2, an output terminal 3, ground terminals 4 and 11, a coil unit 55, and a magnetic core 6, and includes a distributed constant type noise filter (low frequency band). It functions as a pass-through normal mode filter.

  As shown in FIG. 11, the coil section 55 includes strip insulators 7 a and 7 b, a ground strip conductor 8, a signal strip conductor 9, and an auxiliary ground conductor 10. In this case, the grounding conductor 8 is overlapped on the strip-like insulator 7a in a state where one end side of the grounding terminal 4 is electrically connected to the grounding portion C defined on one end side (winding end end side). It has been. Further, in the grounding conductor 8, the signal conductor 9 including the output part B to which the output terminal 3 is connected is opposed to the other end side (the right end side in the figure) (the part on the winding start end side). Is separated (divided) from other parts. The auxiliary grounding conductor 10 is formed at a portion of the grounding conductor 8 on the winding start end side, and is connected to the grounding terminal 11. Further, the length of the auxiliary grounding conductor 10 (referring to the length along the length direction of the grounding conductor 8) is sufficiently shorter than the remaining portion of the grounding conductor 8. It is prescribed as follows. Specifically, the auxiliary grounding conductor 10 is defined within a length of 1/5 of the grounding conductor 8. Hereinafter, in this best mode, another part (remaining part) of the grounding conductor 8 from which the auxiliary grounding conductor 10 is separated will be described as the grounding conductor 8. The strip insulator 7b is overlaid on the strip insulator 7a so that the ground conductor 8 and the auxiliary ground conductor 10 are sandwiched between the strip insulator 7a. The signal conductor 9 is connected to the input part A defined on one end side (winding end side) and output to the output part B defined on the other end side (winding end side). With the terminal 3 connected, it is overlaid on the strip insulator 7b.

  The coil portion 55 includes the strip insulators 7a and 7b and the conductors 8, 9, and 10 stacked on each other in this manner, as shown by arrows in FIG. As shown in FIG. 1, it is formed into a cylindrical shape by winding the grounding conductor 8 on the signal conductor 9 so that the grounding conductor 8 is on the outside. . Therefore, in this coil portion 55, the auxiliary grounding conductor 10 is opposed to the other end side (innermost peripheral portion) of the signal conductor 9 in which the output portion B is defined, with the belt-like insulator 7b interposed. is doing. The conductors 8 and 10 and the signal conductor 9 are wound in a state of being insulated from each other because the band-like insulator 7b is interposed therebetween. The grounding conductor 8 and the auxiliary grounding conductor 10 are wound while maintaining a separated state, that is, while maintaining a non-contact state (insulating state). The magnetic core 6 is mounted in the gap H and disposed at the center of the coil portion 5. In this case, the input part A of the signal conductor 9 (drawing part of the input terminal 2), the output part B of the signal conductor 9 (drawing part of the output terminal 3), and the grounding part C of the grounding conductor 8 ( Similarly to the filter element 1, the lead-out portion of the grounding terminal 4 is located at the position shown in FIG. As shown in FIG. 1, the grounding terminal 11 is drawn from the vicinity of the drawing portion B (see FIG. 2) of the output terminal 3.

(Sixth best mode)
Next, the configuration of the filter element 61 will be described with reference to FIGS. Since the configuration of the filter element 61 is similar to the configuration of the filter element 21, the same configuration as the filter element 21 is denoted by the same reference numeral, and redundant description is omitted.

  As shown in FIG. 4, the filter element 61 includes an input terminal 2, an output terminal 3, grounding terminals 4, 11, a coil unit 65, and a magnetic core 6, and is a distributed constant type noise filter (low frequency band). It functions as a pass-through normal mode filter.

  As shown in FIG. 12, the coil section 65 includes strip-shaped insulators 7a and 7b, a ground strip-shaped conductor 8, a signal strip-shaped conductor 9, and an auxiliary ground conductor 10. In this case, the signal conductor 9 has the output terminal 3 connected to the output part B defined on one end side (winding end side) and the input part defined on the other end side (winding end side). The input terminal 2 is connected to A and is overlaid on the strip insulator 7a. The strip-shaped insulator 7b is overlaid on the strip-shaped insulator 7a so that the signal conductor 9 is sandwiched between the strip-shaped insulator 7a. The grounding conductor 8 is overlaid on the strip-like insulator 7b in a state where the grounding terminal 4 is connected to the grounding portion C defined on the other end side (winding start end side). Further, in the grounding conductor 8, the signal conductor 9 including the output part B to which the output terminal 3 is connected has a part (a part on the winding end side) facing the one end side (the right end side in the figure). It is separated (divided) from other parts. The auxiliary grounding conductor 10 is formed in the separated winding end side portion of the grounding conductor 8 and connected to the grounding terminal 11. Further, the length of the auxiliary grounding conductor 10 (referring to the length along the length direction of the grounding conductor 8) is the same as that of the filter element 51, and the remaining portion of the grounding conductor 8 is left. It is specified to be sufficiently shorter than Hereinafter, in this best mode, another part (remaining part) of the grounding conductor 8 from which the auxiliary grounding conductor 10 is separated will be described as the grounding conductor 8.

  The coil portion 65 includes the strip insulators 7a and 7b and the conductors 8, 9, and 10 stacked on each other in this manner, as shown by arrows in FIG. As shown in FIG. 4, a gap is formed at the center as shown in FIG. 4 by winding the signal conductor 9 on the outer side with respect to the grounding conductor 8. It is formed in a cylindrical shape with H formed. Therefore, in this coil portion 65, the auxiliary grounding conductor 10 is opposed to one end side (outermost peripheral portion) of the signal conductor 9 in which the output portion B is defined, with the band-like insulator 7b interposed. Yes. The conductors 8 and 10 and the signal conductor 9 are wound in a state of being insulated from each other because the band-like insulator 7b is interposed therebetween. The grounding conductor 8 and the auxiliary grounding conductor 10 are wound while maintaining a separated state, that is, while maintaining a non-contact state (insulating state). A magnetic core 6 is mounted in the gap H of the coil portion 65. In this case, the input part A of the signal conductor 9 (the lead-out part of the input terminal 2), the output part B of the signal conductor 9 (the lead-out part of the output terminal 3), and the grounding part C of the grounding conductor 8 ( The lead-out portion of the grounding terminal 4 is located at the position shown in FIG. As shown in FIG. 4, the grounding terminal 11 is drawn out from the vicinity of the lead-out portion B (see FIG. 5) of the output terminal 3.

  In the filter elements 51 and 61 described above, the filter element 51 is output between the innermost peripheral portion of the signal conductor 9 in which the output portion B is defined and the auxiliary grounding conductor 10 and the filter element 61 is output. Capacitances are formed in a distributed constant manner between the outermost peripheral portion of the signal conductor 9 in which the portion B is defined and the auxiliary grounding conductor 10, and the total length is short, that is, the potential increases due to the inductance. This capacitance is grounded via a small number of auxiliary grounding conductors 10. For this reason, according to the filter elements 51 and 61, the capacitance formed between the signal conductor 9 and the auxiliary grounding conductor 10 at the innermost or outermost peripheral portion to which the output terminal 3 is connected. As a result, noise can be satisfactorily bypassed to the grounding side, so that it is possible to maintain good attenuation characteristics even in a high frequency region (for example, a frequency region of 3 MHz or more). In the filter elements 51 and 61, the positions of the input part A (the lead part of the input terminal 2), the output part B (the lead part of the output terminal 3), and the ground part C (the lead part of the grounding terminal 4) are set to the positions described above. By defining as described above, a large attenuation amount can be secured in a predetermined frequency band, and as a result, a normal mode filter element having excellent attenuation characteristics can be realized. Furthermore, compared with the filter elements 1 and 21, the strip-like insulator 7c can be eliminated, so that the size and weight can be reduced.

(Seventh best mode)
Next, the configuration of the filter element 71 will be described with reference to FIGS. In addition, since the structure of the filter element 71 is similar to the structure of the filter element 31, the same reference numeral is given to the same configuration as the filter element 31, and a duplicate description is omitted.

  As shown in FIG. 7, the filter element 71 includes a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, ground terminals 4 and 11, a coil portion 75, and a magnetic core 6, and is distributed. Functions as a constant type common mode noise filter (low-pass filter).

  As shown in FIG. 13, the coil portion 75 includes strip-shaped insulators 7 a and 7 b, a ground strip-shaped conductor 8, a pair of signal conductors 9 a and 9 b, and an auxiliary ground conductor 10. In this case, the grounding conductor 8 is overlaid on the strip-like insulator 7a in a state where the grounding terminal 4 is connected to the grounding portion C defined on one end side (winding end end side). Further, in the grounding conductor 8, the signal conductor 9 including the output part B to which the output terminal 3 is connected is opposed to the other end side (the right end side in the figure) (the part on the winding start end side). Is separated (divided) from other parts. The auxiliary grounding conductor 10 is formed at the separated winding start end portion of the grounding conductor 8 and connected to the grounding terminal 11. Similarly to the filter element 51, the auxiliary grounding conductor 10 has a length (referred to as a length along the length direction of the grounding conductor 8) that is the same as the remaining part of the grounding conductor 8. It is specified to be sufficiently short in comparison. The strip insulator 7b is overlaid on the strip insulator 7a so that the ground conductor 8 and the auxiliary ground conductor 10 are sandwiched between the strip insulator 7a. Each of the signal conductors 9a and 9b has an input terminal 2a and 2b connected to an input portion A defined on one end side (winding end side), and is defined on the other end side (winding end side). The output terminals 3a and 3b are respectively connected to the output region B, and are overlaid on the strip insulator 7b. Hereinafter, in this best mode, another part (remaining part) of the grounding conductor 8 from which the auxiliary grounding conductor 10 is separated will be described as the grounding conductor 8.

  The coil portion 75 is configured so that the band-like insulators 7a and 7b and the conductors 8, 9a, 9b, and 10 overlapped with each other as described above are shown on the conductor 10 side (in FIG. And the grounding conductor 8 is wound around the signal conductors 9a and 9b so that the gap H is formed at the center as shown in FIG. It is formed in the cylindrical shape formed. Therefore, in this coil part 75, the auxiliary grounding conductor 10 is in a state where the strip-like insulator 7b is interposed, and the other end side (the innermost peripheral part) of each of the signal conductors 9a and 9b in which the output part B is defined. ). The conductors 8 and 10 and the signal conductors 9 are wound in a state of being insulated from each other because the band-like insulator 7b is interposed therebetween. The grounding conductor 8 and the auxiliary grounding conductor 10 are wound while maintaining a separated state, that is, while maintaining a non-contact state (insulating state). The magnetic core 6 is mounted in the gap H and disposed at the center of the coil portion 75. In this case, the input part A of each signal conductor 9 (leading part of each input terminal 2a, 2b), the output part B of each signal conductor 9 (leading part of each output terminal 3a, 3b), and grounding The grounding part C of the conductor 8 (the lead-out part of the grounding terminal 4) is located at the position shown in FIG. As shown in FIG. 7, the grounding terminal 11 is drawn out from the vicinity of the lead-out part B (see FIG. 2) of each output terminal 3a, 3b.

(Eighth best mode)
Next, the configuration of the filter element 81 will be described with reference to FIGS. In addition, since the structure of the filter element 81 is similar to the structure of the filter element 41, the same reference numerals are given to the same configuration as the filter element 41, and redundant description is omitted.

  As shown in FIG. 9, the filter element 81 includes a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, ground terminals 4 and 11, a coil portion 85, and a magnetic core 6, and is distributed. Functions as a constant type common mode noise filter (low-pass filter).

  As shown in FIG. 14, the coil portion 85 includes strip-shaped insulators 7 a and 7 b, a ground strip-shaped conductor 8, a pair of signal conductors 9 a and 9 b, and an auxiliary ground conductor 10. In this case, each of the signal conductors 9a and 9b has the output terminals 3a and 3b connected to the output portion B defined on one end side (winding end side) and the other end side (winding end side). The input terminals 2a and 2b are connected to the defined input part A and overlapped on the strip insulator 7a. The strip insulator 7b is superimposed on the strip insulator 7a so that the signal conductors 9a and 9b are sandwiched between the strip insulator 7a. The grounding conductor 8 is overlaid on the strip-like insulator 7b in a state where the grounding terminal 4 is connected to the grounding portion C defined on the other end side (winding start end side). Further, in the grounding conductor 8, the signal conductor 9 including the output part B to which the output terminal 3 is connected has a part (a part on the winding end side) facing the one end side (the right end side in the figure). Separated from other sites. The auxiliary grounding conductor 10 is formed in the separated winding end side portion of the grounding conductor 8 and connected to the grounding terminal 11. Similarly to the filter element 51, the auxiliary grounding conductor 10 has a length (referred to as a length along the length direction of the grounding conductor 8) that is the same as the remaining part of the grounding conductor 8. It is specified to be sufficiently short in comparison.

  The coil portion 85 includes the strip-like insulators 7a and 7b and the conductors 8, 9a, 9b, and 10 stacked on top of each other in addition to the conductors 8 and 9, as indicated by arrows in FIG. As shown in FIG. 9, by winding the signal conductors 9a and 9b on the grounding conductor 8 so that the signal conductors 9a and 9b are on the outside, starting from the end side (left end in the figure). , It is formed in a cylindrical shape with a gap H formed in the center. Therefore, in this coil portion 85, the auxiliary grounding conductor 10 is connected to one end side (the outermost peripheral portion) of each of the signal conductors 9a and 9b in which the output portion B is defined with the strip-like insulator 7b interposed. Opposite. The conductors 8 and 10 and the signal conductors 9 are wound in a state of being insulated from each other because the band-like insulator 7b is interposed therebetween. The grounding conductor 8 and the auxiliary grounding conductor 10 are wound while maintaining a separated state, that is, while maintaining a non-contact state (insulating state). A magnetic core 6 is mounted in the gap H of the coil portion 85. In this case, the input part A of each signal conductor 9 (drawing part of the input terminal 2), the output part B of each signal conductor 9 (drawing part of the output terminal 3), and the grounding part of the grounding conductor 8 C (the lead portion of the grounding terminal 4) is located at the position shown in FIG. As shown in FIG. 9, the grounding terminal 11 is drawn from the vicinity of the drawing portion B (see FIG. 5) of the output terminal 3.

  In the filter elements 71 and 81 described above, with respect to common mode noise, a pair of input terminals 2a and 2b (a pair of input portions A), a pair of signal conductors 9a and 9b, and the filter elements 31 and 41, A pair of output terminals 3a and 3b (a pair of output parts B) are respectively connected to one input terminal 2 (one input part A), one signal conductor 9 and one output terminal 3 (one output part B). Can be regarded as Therefore, the filter elements 71 and 81 exhibit good attenuation characteristics with respect to common mode noise in the same manner as the filter elements 51 and 61 function to exhibit good attenuation characteristics with respect to normal mode noise. Function. Further, similarly to the filter elements 51 and 61, the strip-like insulator 7c can be eliminated, so that the filter element can be reduced in size and weight.

  The present invention is not limited to the configuration described above. For example, in each of the filter elements 1, 31, 51, 71 and the filter elements 21, 41, 61, 81 described above, the output part B (the extraction part of the output terminal 3 (3a, 3b)) is shown in FIGS. As shown in the figure, the filter elements 91, 111, 131, 151 shown in FIGS. 15 and 19 are defined so as to be located on the opposite side of the input terminal 2 (2a, 2b) with the central axis O therebetween. As shown in each of the filter elements 101, 121, 141, 161 shown in FIGS. 17 and 20, the output portion B (output terminal 3 (output terminal 3) is positioned on the same side as the input terminal 2 (2a, 2b) with respect to the central axis O. It is also possible to define the extraction part 3a, 3b). Hereinafter, each filter element 91,111,131,151 and each filter element 101,121,141,161 are demonstrated concretely.

(Ninth best form)
First, the filter element 91 according to the present embodiment will be described with reference to FIGS. The filter element 91 has the same configuration as that of the filter element 1 except for the arrangement of the lead-out portion B with respect to the output terminal 3, and therefore the same configuration as the filter element 1 is denoted by the same reference numeral and overlapped. Description is omitted.

  As shown in FIG. 15, the filter element 91 includes an input terminal 2, an output terminal 3, grounding terminals 4, 11, a coil unit 95, and a magnetic core 6, and is a distributed constant type noise filter (low frequency band). It functions as a pass-through normal mode filter.

  As shown in FIG. 3, the coil portion 95 includes strip-shaped insulators 7 a, 7 b, 7 c, a grounding conductor 8, a signal conductor 9, and an auxiliary grounding conductor 10. In this case, the strip insulators 7 a, 7 b, 7 c, the grounding conductor 8, the signal conductor 9, and the auxiliary grounding conductor 10 are overlapped with each other in the same manner as the coil portion 5. Further, the grounding terminal C defined in the grounding conductor 8 has the grounding terminal 4, the input part A and the output part B defined in the signal conductor 9 have the input terminal 2 and the output terminal 3, Further, the grounding terminals 11 are connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 5. As for the auxiliary grounding conductor 10, as shown by the solid line in FIG. 3, the auxiliary grounding conductor 10 may be disposed at a position where the signal conductor 9 is sandwiched between the grounding conductor 8. Alternatively, as indicated by a broken line in the figure, an auxiliary grounding conductor 10 can be disposed between the grounding conductor 8 and the signal conductor 9.

  The coil portion 95 includes the strip insulators 7a, 7b, 7c and the conductors 8, 9, 10 that are stacked on each other as shown by arrows in FIG. As shown in FIG. 15, by winding the other end side (the right end side in the figure) with the grounding conductor 8 on the outside with respect to the signal conductor 9, the winding is started. It is formed in a cylindrical shape with a gap H formed in the center. Therefore, in this coil portion 95, the auxiliary grounding conductor 10 is connected to the other end side (innermost peripheral portion) of the signal conductor 9 in which the output portion B is defined with the band-like insulator 7c interposed therebetween. ). The magnetic core 6 is mounted in the gap H and disposed at the center of the coil portion 95.

  In this case, the input part A of the signal conductor 9 is the same as the coil part 5 as shown in FIG. 16 when the coil part 95 is viewed from one end face (upper end face in FIG. 15) side. The coil portion 95 is located on the outer peripheral side portion. Further, as shown in FIG. 15, the input terminal 2 connected to the input part A of the signal conductor 9 is on one end face (upper end face in the figure) of the coil part 95 in the same manner as the coil part 5. The other end side is drawn out from the outer peripheral side portion. For this reason, in the state which looked at the coil part 95 from the one end surface side, the input site | part A of the signal conductor 9 and the extraction | drawer site | part of the input terminal 2 correspond substantially. On the other hand, the grounding portion C of the grounding conductor 8 is located at the outer peripheral side portion of the coil portion 95 as shown in FIG. 16 when the coil portion 95 is viewed from one end face side. Further, as shown in FIG. 15, the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 has the other end side from the outer peripheral side part on one end face of the coil part 95 in the same manner as the coil part 5. Has been pulled out. For this reason, when the coil portion 95 is viewed from one end face side, the grounding portion C of the grounding conductor 8 and the lead-out portion of the grounding terminal 4 substantially coincide. Here, as shown in FIG. 16, the grounding portion C of the grounding conductor 8 (that is, the lead-out portion C of the grounding terminal 4) is the center axis O of the coil portion 5 and the input portion A (that is, the lead-out portion of the input terminal 2). It is set on the plane L including the part A) on the opposite side to the input part A across the central axis O. Further, when the coil portion 95 is viewed from one end face side, the output portion B of the signal conductor 9 is the same as the coil portion 5 as shown in FIG. It is located on the (circumferential side). Further, as shown in FIG. 15, the output terminal 3 connected to the output part B of the signal conductor 9 is drawn at a substantially right angle from the inner peripheral part of one end face of the coil portion 95. . For this reason, in the state which looked at the coil part 95 from the one end surface side, the output site | part B of the signal conductor 9 and the extraction | drawer site | part of the output terminal 3 correspond substantially. Here, the output portion B of the signal conductor 9 (the lead-out portion B of the output terminal 3) is on the plane L and sandwiches the central axis O, unlike the coil portion 5, as shown in FIG. It is set on the opposite side to the ground contact portion C. That is, the output part B (the lead part of the output terminal 3) of the signal conductor 9 is located on the same side as the input part A (the lead part of the input terminal 2) with respect to the central axis O. As shown in FIG. 15, the grounding terminal 11 is drawn out from the vicinity of the lead-out part B of the output terminal 3, which is an inner peripheral part of one end face of the coil portion 95.

(10th best mode)
Next, the filter element 101 according to this embodiment will be described with reference to FIGS. The filter element 101 has the same configuration as that of the filter element 21 except for the arrangement of the lead-out portion B with respect to the output terminal 3, and therefore the same configuration as the filter element 21 is denoted by the same reference numeral and overlapped. Description is omitted.

  As shown in FIG. 17, the filter element 101 includes an input terminal 2, an output terminal 3, ground terminals 4 and 11, a coil unit 105, and a magnetic core 6. It functions as a pass-through normal mode filter).

  As shown in FIG. 6, the coil portion 105 includes strip-shaped insulators 7 a, 7 b, 7 c, a grounding conductor 8, a signal conductor 9, and an auxiliary grounding conductor 10. In this case, the strip insulators 7 a, 7 b, 7 c, the grounding conductor 8, the signal conductor 9 and the auxiliary grounding conductor 10 are overlapped with each other in the same manner as the coil portion 25. Further, the grounding terminal C defined in the grounding conductor 8 has the grounding terminal 4, the input part A and the output part B defined in the signal conductor 9 have the input terminal 2 and the output terminal 3, Further, the grounding terminal 11 is connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 25. As for the auxiliary grounding conductor 10, as shown by a solid line in FIG. 6, the auxiliary grounding conductor 10 can be disposed between the grounding conductor 8 and the signal conductor 9, As indicated by a broken line in the figure, the auxiliary grounding conductor 10 may be disposed at a position where the signal conductor 9 is sandwiched between the grounding conductor 8.

  The coil portion 105 includes the strip-like insulators 7a, 7b, 7c and the conductors 8, 9, 10 that are overlapped with each other in addition to the conductors 8, 9 as indicated by arrows in FIG. As shown in FIG. 17, by winding the end side (the left end side in the drawing) so that the signal conductor 9 is wound outside the grounding conductor 8, It is formed in a cylindrical shape in which a gap H is formed. Therefore, in this coil part 105, the auxiliary grounding conductor 10 is connected to one end side (outermost peripheral part) of the signal conductor 9 in which the output part B is defined with the band-like insulator 7c interposed therebetween. Opposite. A magnetic core 6 is mounted in the gap H of the coil portion 105.

  In this case, the input part A of the signal conductor 9 is the same as the coil part 25 as shown in FIG. 18 when the coil part 105 is viewed from one end face (upper end face in FIG. 17) side. The coil portion 105 is located on the inner peripheral side portion. Further, as shown in FIG. 17, the input terminal 2 connected to the input portion A of the signal conductor 9 is in the same manner as the coil portion 25 on one end face (upper end face in the figure) of the coil portion 105. The other end side is pulled out from the inner peripheral side portion. For this reason, in the state which looked at the coil part 105 from the one end surface side, the input site | part A of the signal conductor 9 and the extraction | drawer site | part of the input terminal 2 correspond substantially. On the other hand, the grounding portion C of the grounding conductor 8 is located at the inner peripheral portion of the coil portion 105 as shown in FIG. 18 when the coil portion 105 is viewed from one end face side. Further, as shown in FIG. 17, the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 is connected to the other end from the inner peripheral side part on one end face of the coil part 105 in the same manner as the coil part 25. The side is pulled out. For this reason, when the coil portion 105 is viewed from one end face side, the grounding portion C of the grounding conductor 8 and the lead-out portion of the grounding terminal 4 substantially coincide. Here, the grounding part C of the grounding conductor 8 (that is, the lead-out part C of the grounding terminal 4) is, as shown in FIG. 18, the central axis O of the coil portion 105 and the input part A (the lead-out part of the input terminal 2). A) is set on the opposite side with respect to the input site A across the central axis O. Further, the output portion B of the signal conductor 9 is located at the outer peripheral side portion of the coil portion 105 as shown in FIG. 18 when the coil portion 105 is viewed from one end face side. Further, as shown in FIG. 17, the output terminal 3 connected to the output part B of the signal conductor 9 is pulled out from the outer peripheral side part on one end face of the coil portion 105. For this reason, in the state which looked at the coil part 105 from the one end surface side, the output site | part B of the signal conductor 9 and the extraction | drawer site | part of the output terminal 3 correspond substantially. Here, the output part B of the signal conductor 9 (the lead part B of the output terminal 3) is on the plane L and sandwiches the central axis O, unlike the coil part 25, as shown in FIG. It is set on the opposite side to the ground contact portion C. That is, the output part B (the lead part of the output terminal 3) of the signal conductor 9 is located on the same side as the input part A (the lead part of the input terminal 2) with respect to the central axis O. As shown in FIG. 17, the grounding terminal 11 is drawn out from the vicinity of the lead-out part B (see FIG. 18) of the output terminal 3, which is the outer peripheral part of one end face of the coil portion 105.

(Eleventh best mode)
Next, the filter element 111 according to this embodiment will be described with reference to FIGS. The filter element 111 has the same configuration as the filter element 31 except for the arrangement of the lead-out portions B for the output terminals 3a and 3b. A duplicate description is omitted.

  As shown in FIG. 19, the filter element 111 includes input terminals 2a and 2b, output terminals 3a and 3b, ground terminals 4 and 11, a coil unit 115, and a magnetic core 6, and is distributed noise type. Functions as a filter (low-pass common mode filter).

  As shown in FIG. 8, the coil section 115 includes strip-like insulators 7a, 7b, 7c, a grounding conductor 8, signal conductors 9a, 9b, and an auxiliary grounding conductor 10. In this case, the strip insulators 7a, 7b, 7c, the grounding conductor 8, the signal conductors 9a, 9b, and the auxiliary grounding conductor 10 are overlapped with each other in the same manner as the coil portion 35. Further, the grounding terminal 4 is provided at the grounding part C defined by the grounding conductor 8, and the input terminals 2a, 2b and the input parts A and B are respectively provided by the signal conductors 9a and 9b. The output terminals 3a and 3b and the grounding terminal 11 are connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 35, respectively. As for the auxiliary grounding conductor 10, as shown by the solid line in FIG. 8, the auxiliary grounding conductor 10 is disposed at a position sandwiching the signal conductors 9 a and 9 b with the grounding conductor 8. Alternatively, as shown by a broken line in the figure, the auxiliary grounding conductor 10 can be disposed between the grounding conductor 8 and the signal conductors 9a and 9b.

  In the coil portion 115, each of the strip insulators 7a, 7b, 7c and the conductors 8, 9a, 9b, 10 stacked on each other as shown by arrows in FIG. , 9b, 10 by winding so that the other end side (the right end side in the figure) starts to be wound and the grounding conductor 8 is outside the signal conductors 9a, 9b. As shown in FIG. 19, it is formed in a cylindrical shape with a gap H formed in the center. Therefore, in this coil portion 115, the auxiliary grounding conductor 10 is in a state where the strip-like insulator 7c is interposed, and the other end side (innermost circumference) of each of the signal conductors 9a and 9b in which the output portion B is defined. Part). The magnetic core 6 is mounted in the gap H and disposed at the center of the coil portion 115. In this case, the input part A of each signal conductor 9 (the lead part of the input terminals 2a and 2b), the output part B of each signal conductor 9 (the lead part of each output terminal 3a and 3b), and the grounding conductor The grounding part C of the body 8 (the lead-out part of the grounding terminal 4) is located at the position shown in FIG. As shown in FIG. 19, the grounding terminal 11 is drawn from the vicinity of the lead-out part B (see FIG. 16) of each output terminal 3a, 3b.

(Twelfth best mode)
Next, the filter element 121 according to this embodiment will be described with reference to FIGS. The filter element 121 has the same configuration as the filter element 41 except for the arrangement of the lead-out site B for the output terminals 3a and 3b. A duplicate description is omitted.

  As shown in FIG. 20, the filter element 121 includes input terminals 2a and 2b, output terminals 3a and 3b, ground terminals 4 and 11, a coil portion 125, and a magnetic core 6, and is a distributed constant type noise. Functions as a filter (low-pass common mode filter).

  As shown in FIG. 10, the coil portion 125 includes strip-like insulators 7a, 7b, 7c, a grounding conductor 8, signal conductors 9a, 9b, and an auxiliary grounding conductor 10. In this case, the strip insulators 7a, 7b, 7c, the grounding conductor 8, the signal conductors 9a, 9b, and the auxiliary grounding conductor 10 are overlapped with each other in the same manner as the coil portion 45. Further, the grounding terminal 4 is provided at the grounding part C defined by the grounding conductor 8, and the input terminals 2a, 2b and the input parts A and B are respectively provided by the signal conductors 9a and 9b. The output terminals 3 a and 3 b and the grounding terminal 11 are connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 45. As for the auxiliary grounding conductor 10, as shown by the solid line in FIG. 10, the auxiliary grounding conductor 10 may be disposed between the grounding conductor 8 and the signal conductors 9a and 9b. In addition, as shown by a broken line in the figure, the auxiliary grounding conductor 10 can be disposed at a position sandwiching the signal conductors 9a and 9b with the grounding conductor 8.

  In the coil portion 125, each of the strip insulators 7a, 7b, 7c and the conductors 8, 9a, 9b, 10 stacked on each other as shown by arrows in FIG. 20 by winding the signal conductors 9a and 9b around the grounding conductor 8 so that the other end side (the left end side in the figure) is started and the grounding conductor 8 is outside. Thus, it forms in the cylindrical shape by which the space | gap H was formed in the center part. Therefore, in this coil part 125, the auxiliary grounding conductor 10 is in a state in which the strip-like insulator 7c is interposed, and one end side (outermost peripheral part) of each of the signal conductors 9a and 9b in which the output part B is defined. Is facing. The magnetic core 6 is mounted in the gap H of the coil part 125. In this case, the input part A of each signal conductor 9 (the lead-out part of the input terminals 2a and 2b), the output part B of each signal conductor 9 (the lead-out part of the output terminals 3a and 3b), and the grounding conductor Similarly to the filter element 101, the grounding portion C 8 (the lead-out portion of the grounding terminal 4) is defined at the position shown in FIG. As shown in FIG. 20, the grounding terminal 11 is drawn from the vicinity of the lead-out part B (see FIG. 18) of each output terminal 3a, 3b.

(13th best mode)
Next, the filter element 131 according to this embodiment will be described with reference to FIGS. The filter element 131 has the same configuration as the filter element 51 except for the configuration of the input terminal 2, the output terminal 3, and the grounding terminal 4, and therefore the same reference numeral is used for the same configuration as the filter element 51. And redundant description is omitted.

  As shown in FIG. 15, the filter element 131 includes an input terminal 2, an output terminal 3, ground terminals 4 and 11, a coil part 135, and a magnetic core 6, and includes a distributed constant type noise filter (low frequency band). It functions as a pass-through normal mode filter).

  As shown in FIG. 11, the coil portion 135 includes strip-shaped insulators 7 a and 7 b, a grounding conductor 8, a signal conductor 9, and an auxiliary grounding conductor 10. In this case, the strip-like insulators 7a and 7b, the grounding conductor 8, the signal conductor 9, and the auxiliary grounding conductor 10 are configured in the same manner as the coil portion 55 and are overlapped with each other in the same manner as the coil portion 55. ing. Further, the grounding terminal C defined in the grounding conductor 8 has the grounding terminal 4, the input part A and the output part B defined in the signal conductor 9 have the input terminal 2 and the output terminal 3, Further, the grounding terminal 11 is connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 55.

  The coil portion 135 starts winding the strip-like insulators 7a and 7b and the conductors 8, 9, and 10 thus stacked on the auxiliary grounding conductor 10 side as indicated by arrows in FIG. As shown in FIG. 15, the signal conductor 9 is wound so that the grounding conductor 8 is on the outer side, thereby forming a cylindrical shape with a gap H formed in the center. Yes. Therefore, in this coil part 135, the auxiliary grounding conductor 10 is opposed to the other end side (innermost peripheral part) of the signal conductor 9 in which the output part B is defined, with the band-like insulator 7b interposed. is doing. The magnetic core 6 is mounted in the gap H and disposed at the center of the coil part 135. On the other hand, the input part A of the signal conductor 9 (drawing part of the input terminal 2), the output part B of the signal conductor 9 (drawing part of the output terminal 3), and the grounding part C (grounding) of the grounding conductor 8 Similarly to the filter element 91, the lead-out portion of the service terminal 4 is defined at the position shown in FIG. As shown in FIG. 15, the grounding terminal 11 is drawn from the vicinity of the drawing portion B (see FIG. 16) of the output terminal 3.

(14th best form)
Next, the filter element 141 according to this embodiment will be described with reference to FIGS. The filter element 141 has the same configuration as the filter element 61 except for the configuration of the input terminal 2, the output terminal 3, and the grounding terminal 4, and therefore the same configuration as the filter element 61 has the same reference numeral. And redundant description is omitted.

  As shown in FIG. 17, the filter element 141 includes an input terminal 2, an output terminal 3, ground terminals 4 and 11, a coil unit 145, and a magnetic core 6, and is a distributed constant type noise filter (low frequency band). It functions as a pass-through normal mode filter.

  As shown in FIG. 12, the coil portion 145 includes strip-shaped insulators 7a and 7b, a grounding conductor 8, a signal conductor 9, and an auxiliary grounding conductor 10. In this case, the strip-like insulators 7a and 7b, the grounding conductor 8, the signal conductor 9, and the auxiliary grounding conductor 10 are configured in the same manner as the coil portion 65 and are overlapped with each other in the same manner as the coil portion 65. ing. Further, the grounding terminal C defined in the grounding conductor 8 has the grounding terminal 4, the input part A and the output part B defined in the signal conductor 9 have the input terminal 2 and the output terminal 3, Further, the grounding terminal 11 is connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 65.

  The coil portion 145 includes the strip-like insulators 7a and 7b and the conductors 8, 9, and 10 that are overlapped with each other, as shown by arrows in FIG. As shown in FIG. 17, a gap is formed at the center as shown in FIG. 17 by winding the signal conductor 9 on the outer side of the grounding conductor 8 with the winding start (left end side in the figure). It is formed in a cylindrical shape with H formed. Therefore, in this coil portion 145, the auxiliary grounding conductor 10 is opposed to one end side (outermost peripheral portion) of the signal conductor 9 in which the output portion B is defined, with the belt-like insulator 7b interposed. Yes. A magnetic core 6 is mounted in the gap H of the coil portion 145. On the other hand, the input part A of the signal conductor 9 (the lead part of the input terminal 2), the output part B of the signal conductor 9 (the lead part of the output terminal 3), and the ground part C (ground) of the grounding conductor 8 Similarly to the filter element 101, the lead-out terminal 4 is defined at the position shown in FIG. 18, and the grounding terminal 11 is drawn from the vicinity of the lead-out part B of the output terminal 3.

(15th best form)
Next, the filter element 151 according to this embodiment will be described with reference to FIGS. The filter element 151 has the same configuration as that of the filter element 71 except for the configuration of the filter element 71 except for the lead-out portions of the input terminals 2a and 2b, the output terminals 3a and 3b, and the grounding terminal 4. Are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 19, the filter element 151 includes input terminals 2a and 2b, output terminals 3a and 3b, ground terminals 4 and 11, a coil portion 155, and a magnetic core 6, and is distributed noise type. Functions as a filter (low-pass common mode filter).

  As shown in FIG. 13, the coil portion 155 includes strip-shaped insulators 7 a and 7 b, a grounding conductor 8, signal conductors 9 a and 9 b, and an auxiliary grounding conductor 10. In this case, the strip insulators 7a and 7b, the grounding conductor 8, the signal conductors 9a and 9b, and the auxiliary grounding conductor 10 are configured in the same manner as the coil portion 75, and are mutually connected in the same manner as the coil portion 75. It is piled up. Further, the grounding terminal 4 is provided in the grounding part C defined in the grounding conductor 8, and the input terminals 2a and 2b are provided in the input part A and the output part B defined in each of the signal conductors 9a and 9b. The output terminals 3a and 3b and the grounding terminal 11 are connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 75, respectively.

  The coil portion 155 is configured so that the strip-like insulators 7a and 7b and the conductors 8, 9a, 9b, and 10 overlapped with each other are connected to the auxiliary grounding conductor 10 side as shown by arrows in FIG. As shown in FIG. 19, a cylindrical shape in which a gap H is formed at the center as shown in FIG. 19 by winding so that the grounding conductor 8 is outside the signal conductors 9a and 9b. Is formed. Therefore, in this coil portion 155, the auxiliary grounding conductor 10 is connected to the other end side (innermost peripheral portion) of the signal conductor 9 in which the output portion B is defined with the band-like insulator 7b interposed therebetween. ). The magnetic core 6 is mounted in the gap H and disposed at the center of the coil portion 155. In this case, the input part A of each signal conductor 9 (the lead-out part of the input terminals 2a and 2b), the output part B of each signal conductor 9 (the lead-out part of the output terminals 3a and 3b), and the grounding conductor Similarly to the filter element 111, the grounding portion C 8 (the lead-out portion of the grounding terminal 4) is defined at the position shown in FIG. As shown in FIG. 19, the grounding terminal 11 is drawn from the vicinity of the drawing portion B (see FIG. 16) of the output terminal 3.

(Sixteenth best mode)
Next, the filter element 161 according to this embodiment will be described with reference to FIGS. The filter element 161 has the same configuration as that of the filter element 81 except for the lead-out portions of the input terminal 2, the output terminal 3, and the ground terminal 4, and therefore the same reference numerals are used for the same configuration as the filter element 81. And redundant description is omitted.

  As shown in FIG. 20, the filter element 161 includes input terminals 2a and 2b, output terminals 3a and 3b, ground terminals 4 and 11, a coil portion 165, and a magnetic core 6, and is distributed noise type. Functions as a filter (low-pass common mode filter).

  As shown in FIG. 14, the coil portion 165 includes strip-shaped insulators 7 a and 7 b, a grounding conductor 8, signal conductors 9 a and 9 b, and an auxiliary grounding conductor 10. In this case, the strip insulators 7a and 7b, the grounding conductor 8, the signal conductors 9a and 9b, and the auxiliary grounding conductor 10 are configured in the same manner as the coil portion 85, and are mutually connected in the same manner as the coil portion 85. It is piled up. In addition, the grounding terminal C is defined in the grounding part C defined in the grounding conductor 8, and the input terminals 2a, 2b and the input parts A and B defined in the signal conductors 9a and 9b. The output terminals 3a and 3b and the grounding terminal 11 are connected to the auxiliary grounding conductor 10 in the same manner as the coil portion 85, respectively.

  The coil section 165 includes the conductors 8, 9 a, 9 b, as shown by the arrows in FIG. 14, as shown by arrows in FIG. 14. 20 by winding the other end side (left end side in the figure) around the grounding conductor 8 so that the signal conductors 9a and 9b are on the outside. Thus, it forms in the cylindrical shape by which the space | gap H was formed in the center part. Therefore, in this coil portion 165, the auxiliary grounding conductor 10 is connected to one end side (outermost circumference) of each of the signal conductors 9a and 9b in which the output portion B is defined with the band-like insulator 7b interposed therebetween. Part). A magnetic core 6 is mounted in the gap H of the coil portion 165. In this case, the input part A of each signal conductor 9 (the lead-out part of the input terminals 2a and 2b), the output part B of each signal conductor 9 (the lead-out part of the output terminals 3a and 3b), and the grounding conductor Similarly to the filter element 121, the grounding portion C 8 (the lead-out portion of the grounding terminal 4) is defined at the position shown in FIG. As shown in FIG. 20, the grounding terminal 11 is drawn from the vicinity of the lead-out part B (see FIG. 18) of the output terminals 3a and 3b.

  The filter elements 91, 101, 131, 141 and the filter elements 111, 121, 151, 161 are the same as the filter elements 1, 21, 51, 61 and the filter elements 31, 41, 71, 81. Thus, a capacitance is formed in a distributed constant between the innermost or outermost part of the signal conductor 9 (9a, 9b) in which the output part B is defined and the auxiliary grounding conductor 10, and The capacitance is grounded via the auxiliary grounding conductor 10 having a short overall length, that is, a small potential increase due to inductance. For this reason, according to each filter element 91,111,131,151 and each filter element 101,121,141,161, the output terminal 3 (3a, 3b) in the signal conductor 9 (9a, 9b) is connected. In the innermost peripheral portion or the outermost peripheral portion, noise can be satisfactorily bypassed to the ground side via a capacitance formed between the auxiliary grounding conductor 10 and, as a result, a high frequency region (for example, 3 MHz or more) In the frequency region, the attenuation characteristics can be maintained well. In addition, the input part A (drawing part of the input terminal 2 (2a, 2b)), the output part B (drawing part of the output terminal 3 (3a, 3b)), and the grounding part C (drawing part of the grounding terminal 4). By defining each position as described above, a large attenuation amount can be secured in a predetermined frequency band, and as a result, a normal mode filter element and a common mode filter element having excellent attenuation characteristics are realized. be able to.

  The present invention is not limited to the configuration described above. For example, in each of the filter elements 1, 21, 31,..., 151, 161 described above, the terminals such as the input terminal 2, the output terminal 3, and the ground terminals 4 and 11 are grounded using a rod-shaped conductor. Although signal input / output is performed, a flexible wiring cable can also be used. In addition, in order to obtain good attenuation characteristics in each of the filter elements 1, 21, 31,... 151, 161, the auxiliary grounding conductor 10 is grounded in a good state (low impedance). For this purpose, for example, a flat conductor having a large cross-sectional area and surface area such as a metal foil is preferably used as the grounding terminal 11 for grounding. Further, in each of the filter elements 31, 41, 71, 81, 111, 121, 151, 161, 161 having a plurality of (for example, two) signal conductors 9 a, 9 b, FIG. , 13 and 14, one grounding conductor 8, 10 is used for each signal conductor 9 a, 9 b, but grounding corresponding to each signal conductor 9 a, 9 b is used. The conductors 8 and 10 can also be composed of a plurality (two as an example) of conductors. According to this configuration, the grounding conductor 8 and the auxiliary grounding conductor 10 can be formed with the minimum necessary conductors, so that the weight of the filter element can be reduced. As an example, a configuration in which two grounding conductors 8a and 8b and two auxiliary grounding conductors 10a and 10b are arranged to face the signal conductors 9a and 9b in FIGS. Shown with a dashed line.

  Further, in each of the filter elements 1, 21, 31,... 151, 161 described above, the magnetic core 6 is mounted inside the gap H formed in each coil part 5, 25, 35,. The example in which the attenuation characteristic is improved by improving the degree of coupling and the distribution inductance of the grounding conductor 8 and the signal conductor 9 (or the signal conductors 9a and 9b) has been described. Instead of 6, it is also possible to employ a configuration in which the coil parts 5, 25, 35,. According to this configuration, while further improving the degree of coupling and distributed inductance of the grounding conductor 8 and the signal conductor 9 (or the signal conductors 9a, 9b), the coil portions 5, 25, 35,..., 155, 165 can be reduced. Further, instead of the pot core, an EI type core or an EE type core can be attached to the coil portions 5, 25, 35,. Moreover, the structure (air core structure) which does not mount | wear a magnetic body inside the space | gap H formed in coil part 5,25,35, ..., 155,165 can also be employ | adopted.

  In each of the filter elements 1, 21, 31,..., 151, 161, the input terminal 2 (2a, 2b), the output terminal 3 (3a, 3b) and the ground terminals 4, 11 are connected to the coil portion. Are arranged only on the same end surface (the upper end surface in FIGS. 1, 4, 7, 9, 15, 17, 19, and 20). However, the input terminal 2 (2a, 2b) and the output terminal 3 (3a, 3b) and the grounding terminals 4 and 11 are only required to be disposed on the plane L including the central axis O of the coil portion, so that the input terminal 2 (2a, 2b), the output terminal 3 (3a, 3b), and It is also possible to adopt a configuration in which some of the ground terminals 4 and 11 are arranged on the end surface opposite to the other terminals (for example, the lower end surface in FIG. 1). In each of the filter elements 1, 21, 31,..., 151, 161, the input terminal 2 (2a, 2b), the output terminal 3 (3a, 3b), and the ground terminals 4, 11 are connected to the coil portion. Although the configuration in which the terminals are arranged on the plane L including the central axis O is adopted, all the terminals are not arranged exactly on the plane L, but the respective terminals are arranged at positions slightly deviated from the plane L. Also good. In this case, although the attenuation characteristics are slightly lower than those of the filter elements 1, 21, 31,... . In other words, the input terminal 2 (2a, 2b), the output terminal 3 (3a, 3b), and the grounding terminals 4, 11 are arranged on the plane L including the central axis O of the coil portion, so that a predetermined frequency is obtained. As a result of being able to secure a larger attenuation in the band, it is possible to realize a normal mode or common mode filter element having even better and best attenuation characteristics. Further, the number of signal conductors is not limited to one and two, and may be three or more. In each of the filter elements 1, 21, 31,..., 151, 161, the input terminal 2, the output terminal 3, and the grounding terminal 4 are connected to the corresponding signal conductor 9 and grounding conductor 8. Connected to the input part A, the output part B and the grounding part C defined in the inner periphery (the part included in the first turn of the winding) or the outermost part (the part included in the first turn of the winding) Without being limited thereto, for example, the inner peripheral portion (a portion included in several turns at the start of winding) or the outer peripheral portion (a portion included in several turns at the end of winding) of the corresponding signal conductor 9 and grounding conductor 8 The input part A, the output part B, and the grounding part C can be respectively defined, and the input terminal 2, the output terminal 3 and the grounding terminal 4 can be connected.

  Further, in each of the filter elements 1, 21, 31,... 151, 161, the coil portions 5, 25, 35, .., 155, 165 are formed so that the strip insulator 7a is on the outermost side. However, the filter elements 1, 31, 51, 71, 71 including the coil portions 5, 35, 55, 75, 95, 115, 135, 155 in which the grounding conductor 8 is located outside the signal conductor 9. 91, 111, 131, 151 are configured such that the outermost peripheral portion of the grounding conductor 8 is positioned on the outermost periphery of the coil portion by switching the positions of the grounding conductor 8 and the strip-like insulator 7a. You can also. According to the filter element configured as described above, the outermost peripheral portion of the grounding conductor 8 is exposed on the outermost periphery of the coil portion. For example, the grounding conductor 8 is directly connected to the ground potential of the printed circuit board. It is possible to reliably and easily ground. As an example, the filter element 1A shown in FIG. 21 includes a coil part 5A configured so that the grounding conductor 8 is located on the outermost periphery with the coil part 5 of the filter element 1 as a base. In this filter element 1A, in FIG. 3, the positions of the strip insulator 7a and the grounding conductor 8 are reversed, the positions of the strip insulator 7b and the signal conductor 9 are reversed, and the strip insulator 7c and the auxiliary conductor 8 In the state where the position of the grounding conductor 10 is reversed, the coil portion 5A is formed by winding these with the right end side in FIG. Although not shown, the signal conductor 9 (or 9a, 9b) may be configured so that the outermost periphery of the signal conductor 9 (or 9a, 9b) is positioned on the outermost periphery of the coil portion, as in the filter element 1A.

  Next, an Example is given and this invention is demonstrated in detail.

(Example 1, Comparative Example 1)
The grounding conductors 8 and 10 having a width of 11 mm, the pair of signal conductors 9a and 9b having a width of 3.1 mm and the same length as the grounding conductor 8, and a thickness of 50 μm are defined. Using a pair of strip insulators 7a, 7b, 7c formed of a polyimide insulating sheet, the ground conductor 8 is outside the signal conductors 9a, 9b, and the coil portion has 35 turns. 35, and the manufactured coil portion 35 was mounted on an EI type core, and Example 1 corresponding to the filter element 31 was obtained. In this case, the length of the auxiliary grounding conductor 10 was set to 0.5 turns starting from the edge of the signal conductors 9a and 9b on the output part B side. In this state, the inductance of the signal conductors 9a and 9b was 12 mH, and the total capacitance existing between the signal conductors 9a and 9b and the grounding conductor 8 was 3300 pF. The capacitance formed between the auxiliary grounding conductor 10 and the signal conductors 9a and 9b was 20 pF.

  Further, the strip insulator 7c and the auxiliary grounding conductor 10 are omitted from the configuration of the first embodiment, the coil portion having the same number of turns as the coil portion 35 is formed, and the same core is attached to the filter element 31. Corresponding Comparative Example 1 was designated.

  Next, the attenuation characteristics for each frequency of the filter elements according to Example 1 and Comparative Example 1 were measured with a network analyzer HP8751A manufactured by HP, and the S21 characteristic (common mode) was measured in a 50Ω system. At this time, a method of simultaneously supplying a test signal to the signal conductors 9a and 9b by short-circuiting the pair of input terminals 2a and 2b and short-circuiting the pair of output terminals 3a and 3b was adopted. Each attenuation characteristic of the filter element according to Example 1 and Comparative Example 1 is shown in FIG. In the figure, the attenuation characteristic of the filter element according to the first embodiment is denoted by reference symbol P, and the attenuation characteristic of the filter element according to the first comparative example is denoted by reference numeral Q.

  According to FIG. 22, both of the attenuation amounts reach a peak at a frequency of about 3 MHz. However, in the filter element according to Comparative Example 1, the attenuation amount rapidly decreases as the frequency increases in a frequency band exceeding about 3 MHz. In a frequency band exceeding about 10 MHz, the attenuation cannot be secured at 50 dB. On the other hand, it was confirmed that the filter element according to Example 1 can secure an attenuation of 50 dB or more up to about 70 MHz.

(Example 2, comparative example 2)
A grounding conductor 8 having a width of 11 mm, a pair of signal conductors 9a and 9b having a width of 3.1 mm, a pair of strip-like insulators 7a formed of a polyimide insulating sheet having a thickness of 50 μm, 7b and 7c are used to produce a coil part 75 having a grounding conductor 8 outside the signal conductors 9a and 9b and having 35 turns, and the produced coil part 75 is an EI type. Example 2 corresponding to the filter element 71 mounted on the core was adopted. In this case, a part of the grounding conductor 8 (the part facing the innermost peripheral portion of the signal conductors 9a and 9b) is moved one turn from the edge of the signal conductors 9a and 9b on the output part B side. The auxiliary grounding conductor 10 was separated (divided) by length. In this state, the inductance of each of the signal conductors 9a and 9b was 12 mH, and the total capacitance existing between the signal conductors 9a and 9b and the grounding conductor 8 was 3300 pF.

  In the manufacturing procedure of the second embodiment, the pair of signal conductors 9a and 9b and the grounding conductor 8 are the same without separating the grounding conductor 8 for forming the auxiliary grounding conductor 10. In the state set to be long, a coil part having the same number of turns as that of the coil part 75 was formed, and the same core was attached to make a comparative example 2 corresponding to the filter element 71.

  Next, the attenuation characteristics for each frequency of the filter elements according to Example 2 and Comparative Example 2 were set under the same conditions as in Example 1 except for the use of the software fixture function of the network analyzer R3767CG manufactured by ADVANTEST. The measurement was performed under the same conditions as in Comparative Example 1. FIG. 23 shows the attenuation characteristics of the filter elements according to Example 2 and Comparative Example 2. In the figure, the attenuation characteristic of the filter element according to the second embodiment is denoted by reference symbol R, and the attenuation characteristic of the filter element according to the second comparative example is denoted by reference numeral S.

  According to FIG. 23, the attenuation amount reaches a peak at a frequency of about 3 MHz in both cases, but in the filter element according to Comparative Example 2, the attenuation amount sharply decreases as the frequency increases in the frequency band exceeding about 3 MHz. However, in a frequency band exceeding about 7 MHz, the attenuation cannot be secured to 60 dB or more. On the other hand, it was confirmed that the filter element according to Example 2 can secure an attenuation of 60 dB or more up to about 30 MHz.

It is a perspective view which shows the structure of the filter element 1 (51). It is the top view which looked at filter element 1 (31, 51, 71) which shows each extraction part A, B, and C of input terminal 2, output terminal 3, and grounding terminal 4 from one end face. In order to show the structure of the filter element 1 (91), it is the perspective view of the state which unwinded the coil part 5 (95). It is a perspective view which shows the structure of the filter element 21 (61). It is the top view which looked at filter element 21 (41, 61, 81) which shows each extraction part A, B, and C of input terminal 2, output terminal 3, and grounding terminal 4 from one end face. In order to show the structure of the filter element 21 (101), it is the perspective view of the state which unwound the coil part 25 (105). It is a perspective view which shows the structure of the filter element 31 (71). In order to show the configuration of the filter element 31 (111), it is a perspective view of a state where the coil portion 35 (115) is unrolled. It is a perspective view which shows the structure of the filter element 41 (81). In order to show the configuration of the filter element 41 (121), it is a perspective view of a state in which the coil portion 45 (125) is unrolled. In order to show the configuration of the filter element 51 (131), it is a perspective view of a state in which the coil portion 55 (135) is unrolled. In order to show the structure of the filter element 61 (141), it is the perspective view of the state which unwound the coil part 65 (145). In order to show the structure of the filter element 71 (151), it is the perspective view of the state which unwound the coil part 75 (155). In order to show the structure of the filter element 81 (161), it is the perspective view of the state which unwinded the coil part 85 (165). It is a perspective view which shows the structure of the filter element 91 (131). It is the top view which looked at filter element 91 (111, 131, 151) which shows each extraction part A, B, and C of input terminal 2, output terminal 3, and grounding terminal 4 from one end face. It is a perspective view which shows the structure of the filter element 101 (141). It is the top view which looked at filter element 101 (121, 141, 161) which shows each extraction part A, B, and C of input terminal 2, output terminal 3, and grounding terminal 4 from one end face. It is a perspective view which shows the structure of the filter element 111 (151). It is a perspective view which shows the structure of the filter element 121 (161). It is a perspective view which shows the structure of 1 A of filter elements. FIG. 6 is an attenuation characteristic diagram showing the relationship between the frequency and the attenuation of the filter element according to Example 1 and Comparative Example 1. It is an attenuation characteristic figure showing the relation between the frequency of the filter element concerning Example 2 and comparative example 2, and the amount of attenuation.

Explanation of symbols

1, 1A, 21, 31, 41, 51, 61, 71, 81, 91, 101, 111, 121, 131, 141, 151, 161 Filter element 2, 2a, 2b Input terminal 3, 3a, 3b Output terminal 4 , 11 Grounding terminal 5, 25, 35, 45, 55, 65, 75, 85, 95, 105, 115, 125, 135, 145, 155, 165 Coil portion 7a, 7b Strip insulator 8 Grounding conductor 9 , 9a, 9b Signal conductor 10 Auxiliary grounding conductor A Input part B Output part C Grounding part O Center axis

Claims (17)

A coil portion formed as a whole by winding one strip-shaped conductor and the other strip-shaped conductor in a state of being overlapped via a strip-shaped insulator,
The one band-shaped conductor has a first connection part connected to the outside defined in the inner peripheral part and a second connection part connected to the outside defined in the outer peripheral part,
In the other band-shaped conductor, a third connection portion connected to the outside is defined in the outer peripheral portion,
A filter element in which a sheet-like conductor is wound around the coil portion so as to face the inner peripheral portion of the one strip-like conductor. A coil portion formed as a whole by winding one strip-shaped conductor and the other strip-shaped conductor in a state of being overlapped via a strip-shaped insulator,
The one band-shaped conductor has a first connection part connected to the outside defined in the outer peripheral part and a second connection part connected to the outside defined in the inner peripheral part,
In the other band-shaped conductor, a third connection portion connected to the outside is defined in the inner peripheral portion,
A filter element in which a sheet-like conductor is wound around the coil portion so as to face the outer peripheral portion of the one strip-like conductor. A coil portion formed in a cylindrical shape as a whole by winding a signal strip conductor and a ground strip conductor in a state of being overlapped via a strip insulator,
The signal strip-shaped conductor has an output portion defined on the inner peripheral portion and an input portion defined on the outer peripheral portion,
The grounding belt-like conductor has a grounding portion defined on the outer periphery,
A filter element in which a sheet-like auxiliary grounding conductor is wound around the coil portion so as to face the inner peripheral portion of the signal strip-like conductor. A coil portion formed in a cylindrical shape as a whole by winding a signal strip conductor and a ground strip conductor in a state of being overlapped via a strip insulator,
The signal strip-shaped conductor has an input part defined on the inner periphery and an output part defined on the outer periphery,
The grounding strip-shaped conductor has a grounding portion defined on the inner periphery,
A filter element in which a sheet-like auxiliary grounding conductor is wound around the coil portion so as to face the outer peripheral portion of the signal strip-like conductor. The grounding part is defined on the opposite side to the input part across the central axis of the coil part,
5. The filter element according to claim 3, wherein the output part is defined on the opposite side to the input part across the central axis of the coil portion. The grounding part is defined on the opposite side to the input part across the central axis of the coil part,
5. The filter element according to claim 3, wherein the output part is defined on the opposite side of the ground part with the central axis of the coil portion interposed therebetween. A coil portion formed in a cylindrical shape as a whole by winding a pair of band-shaped conductors and other band-shaped conductors in a state of being overlapped via a band-shaped insulator,
In the pair of strip conductors, a first connection portion connected to the outside is defined in each inner peripheral portion and a second connection portion connected to the outside is defined in each outer peripheral portion, respectively.
In the other strip-shaped conductor, a third connection portion connected to the outside is defined in the outer peripheral portion,
A filter element in which a sheet-like conductor is wound around the coil portion so as to face the inner peripheral portions of the pair of strip-like conductors. A coil portion formed in a cylindrical shape as a whole by winding a pair of band-shaped conductors and other band-shaped conductors in a state of being overlapped via a band-shaped insulator,
The pair of strip conductors has a first connection part connected to the outside defined in each outer peripheral part and a second connection part connected to the outside defined in each inner peripheral part,
In the other band-shaped conductor, a third connection portion connected to the outside is defined in the inner peripheral portion,
A filter element in which a sheet-like conductor is wound around the coil portion so as to face the outer peripheral portions of the pair of strip-like conductors. A coil portion formed in a cylindrical shape as a whole by winding a pair of signal strip conductors and a ground strip conductor in a state of being overlapped via a strip insulator,
In the pair of signal strip conductors, an output portion is defined on each inner peripheral portion and an input portion is defined on each outer peripheral portion, respectively.
The grounding belt-like conductor has a grounding portion defined on the outer periphery,
A filter element in which a sheet-like auxiliary grounding conductor is wound around the coil portion so as to face the inner peripheral portions of the pair of signal strip-like conductors. A coil portion formed in a cylindrical shape as a whole by winding a pair of signal strip conductors and a ground strip conductor in a state of being overlapped via a strip insulator,
Each of the pair of signal strip conductors has an input portion defined on each inner peripheral portion and an output portion defined on each outer peripheral portion,
The grounding strip-shaped conductor has a grounding portion defined on the inner periphery,
A filter element in which a sheet-like auxiliary grounding conductor is wound around the coil portion so as to face the outer peripheral portion of the pair of signal strip conductors. The grounding part is defined on the opposite side with respect to each input part across the central axis of the coil part,
11. The filter element according to claim 9, wherein each output portion is defined on the opposite side to each input portion with a central axis of the coil portion interposed therebetween. The grounding part is defined on the opposite side with respect to each input part across the central axis of the coil part,
11. The filter element according to claim 9, wherein each of the output portions is defined on the opposite side of the ground portion with the central axis of the coil portion interposed therebetween.   The filter element according to claim 9, wherein a pair of the auxiliary grounding conductors are provided so as to face the pair of signal strip conductors.   The auxiliary grounding conductor is a portion of the grounding strip conductor facing the inner peripheral portion or the outer peripheral portion where the output portion of the signal strip conductor is defined. The filter element according to any one of claims 3 to 6 and 9 to 13, wherein the filter element is configured to be separated from the portion. An output terminal is connected to the first connection site;
An input terminal is connected to the second connection site;
A grounding terminal is connected to the third connection site;
The filter element according to claim 1, wherein an auxiliary grounding terminal is connected to the sheet-like conductor. An input terminal is connected to the input part,
An output terminal is connected to the output site;
A grounding terminal is connected to the grounding site;
The filter element according to any one of claims 3 to 6 and 9 to 14, wherein an auxiliary grounding terminal is connected to the auxiliary grounding conductor.   The filter element according to any one of claims 1 to 16, wherein a magnetic body is disposed in a gap formed in a central portion of the coil portion.

Images