JP2006340030A - Filter element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter element which has excellent attenuation characteristics to both common-mode noise and normal-mode noise. <P>SOLUTION: The filter element has a coil part 5 formed in a cylindrical shape on the whole by winding beltlike conductors 9a and 9b for signal and a beltlike conductor 8 for grounding one over the other across a beltlike insulator 7b so that the beltlike conductor 8 for grounding is outside the beltlike conductors 9a and 9b for signal. The beltlike conductors 9a and 9b for signal have output positions defined at inner peripheral parts and input positions defined at outer peripheral parts respectively, the beltlike conductor 8 for grounding has a grounding position defined at an outer peripheral part, and the coil part 5 is wound with a sheet type conductor 10 in a floating state opposite the beltlike conductors 9a and 9b for signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

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 type of filter element, a filter element disclosed 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. It functions as a three-terminal type 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 strip conductor for energization, and the strip strip conductor for grounding extends over the entire length of the strip conductor for energization. A capacitance is distributed between the body and the body. Therefore, this filter element can realize an excellent attenuation characteristic over a wide frequency band.
Japanese Patent No. 2826320 (2nd page)

  Incidentally, in recent years, a noise filter for common mode using the configuration of the normal mode type noise filter described above has also been developed. For example, it is expected to be used as a noise filter for AC input in a switching power supply. However, in the common mode type noise filter using the configuration of the normal mode type noise filter described above, even if the attenuation characteristic with respect to the common mode noise is good, the attenuation characteristic with respect to the normal mode noise is often not good. Therefore, it is desired to realize a common mode type noise filter that has both good attenuation characteristics for common mode noise and good attenuation characteristics for normal mode noise.

  The present invention has been made in view of the above-described demands, and a main object of the present invention is to provide a filter element having good attenuation characteristics with respect to common mode noise and attenuation characteristics with respect to normal mode noise.

  In order to achieve the above object, the filter element according to claim 1 is configured such that a pair of signal strip conductors and a ground strip conductor are overlapped via a strip insulator with respect to the pair of signal strip conductors. And a coil portion formed in a cylindrical shape as a whole by winding the grounding strip-shaped conductor so as to be on the outside, and each of the pair of signal strip-shaped conductors has an output portion at each inner peripheral portion. In addition, an input site is defined on each outer peripheral portion, and the grounding strip conductor is defined on the outer peripheral portion, and the coil portion is opposed to the pair of signal strip conductors. Thus, the sheet-like conductor is wound in a floating state. Here, the “strip-shaped conductor” in the present invention 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 formed in a round shape, an ellipse shape, a square shape, or a trapezoid shape. It is meant to include a flexible plate-like conductor. Further, the “floating state” of the sheet-like conductor means a state where the sheet-like conductor is insulated from the signal conductor and the grounding conductor. Further, the “inner peripheral part” means a part included in several turns at the beginning of winding in the signal strip conductor or the ground strip conductor, and the “outer peripheral portion” means the signal strip conductor or the ground strip. This refers to a portion included in several turns at the end of winding in a conductor.

  According to a second aspect of the present invention, the pair of signal strip conductors and the ground strip conductor are overlapped via a strip insulator with respect to the pair of signal strip conductors. Each of the pair of signal strip conductors has an input portion defined on each inner peripheral portion thereof, and includes a coil portion formed in a cylindrical shape as a whole by winding the strip conductor so as to be inside. An output part is defined in each outer peripheral part, and the grounding strip conductor has a grounding part defined in an inner peripheral part, and the coil part is disposed so as to face the pair of signal strip conductors. The conductor is wound in a floating state.

  According to a third aspect of the present invention, in the filter element according to the first or second aspect, a pair of the sheet-like conductors are provided so as to face the pair of signal strip-like conductors.

  According to a fourth aspect of the present invention, in the filter element according to claim 4, the grounding strip conductor is placed on the signal strip conductor in a state where the strip strip conductor for signal and the ground strip conductor are overlapped via the 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 strip-shaped conductor has a grounding portion defined on the outer peripheral portion, and a sheet-shaped conductor is wound around the coil portion so as to face the signal strip-shaped conductor.

  According to a fifth aspect of the present invention, in the filter element according to the fifth aspect, the grounding strip conductor is placed on the signal strip conductor in a state where the strip strip conductor for signal and the ground strip conductor are overlapped via the strip insulator. The signal belt-like conductor has an input portion defined on the inner peripheral portion and an output portion defined on the outer peripheral portion. The grounding strip-shaped conductor has a grounding portion defined on the inner periphery thereof, and the coil-shaped conductor is wound in a floating state so as to face the signal strip-shaped conductor.

  Further, the filter element according to claim 6 is the filter element according to any one of claims 1 to 5, wherein the sheet-like conductor is a part of the grounding strip-shaped conductor. It is configured to be separated from other parts.

  The filter element according to claim 7 is the filter element according to any one of claims 1 to 6, wherein the grounding part is located on the opposite side of the input part across the center of the coil portion. The output part is located on the opposite side of the input part with the center of the coil portion interposed therebetween.

  The filter element according to claim 8 is the filter element according to any one of claims 1 to 6, wherein the grounding portion is located on the opposite side to the input portion across the center of the coil portion. The output part is located on the opposite side of the ground part with the center of the coil portion interposed therebetween.

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

  The filter element according to claim 10 is the filter element according to any one of claims 1 to 9, wherein an input terminal is connected to the input part, an output terminal is connected to the output part, and a ground terminal is provided. It is connected to the grounding part. Here, the “terminal” in the present invention means not only a rod-shaped conductor but also a flexible wiring cable, and further includes a flat conductor such as a metal foil.

  According to the filter element of claim 1, each signal strip conductor, the ground strip conductor, and the strip insulator are wound so that the ground strip conductor is outside the signal strip conductor. The coil part is formed in a cylindrical shape as a whole, the output part is defined on each inner peripheral part of each signal strip conductor, and the input part is defined on each outer periphery part of each signal strip conductor, By defining a grounding part on the outer periphery of the strip-shaped conductor for signal and winding the sheet-shaped conductor in a floating state so as to face each strip-shaped conductor for signal, the sheet-shaped conductor is placed between the strip-shaped conductors for signal. In addition, a capacitive component is formed. For this reason, the characteristic impedance of the line suddenly changes discontinuously, and as a result of reflection of the signal (normal mode signal), propagation of the normal mode signal is hindered. Therefore, according to this filter element, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise while maintaining the attenuation characteristic with respect to the common mode noise in a good state.

  Further, according to the filter element of the second aspect, the signal conductor, the grounding conductor, and the belt-like insulators are wound so that the grounding conductor is inside the signal conductor. A coil portion is formed in a cylindrical shape as a whole, an input portion is defined on each inner peripheral portion of each signal conductor, and an output portion is defined on each outer peripheral portion of each signal conductor. By defining a grounding part on the inner periphery of the sheet and winding the sheet-like conductor in a floating state so as to face each signal conductor, the sheet-like conductor has a capacitance component between the signal-band conductors. Form. For this reason, since the characteristic impedance of the line suddenly changes discontinuously, signal reflection occurs and propagation is hindered. Therefore, according to this filter element, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise while maintaining the attenuation characteristic with respect to the common mode noise in a good state.

  Further, in each filter element according to claim 3, by providing a pair of sheet-like conductors so as to face each signal conductor, a portion that does not face each signal conductor (each sheet-like shape). Since it is not necessary to dispose the conductor in a portion facing the region sandwiched between the conductors, each sheet-like conductor can be formed with the minimum necessary conductor. Therefore, the weight of the filter element can be reduced.

  According to the filter element of claim 4, the signal strip conductor, the ground strip conductor, and the strip insulator are wound so that the ground strip conductor is outside the signal strip conductor. The coil part is formed in a cylindrical shape as a whole, the output part is defined on the inner periphery of the signal strip conductor, the input part is defined on the outer periphery of the signal strip conductor, and the outer periphery of the ground strip conductor The sheet-like conductor forms a capacitance component between the signal strip-shaped conductors by defining a grounding portion in the portion and winding the sheet-shaped conductor in a floating state so as to face the signal strip-shaped conductor. . For this reason, since the characteristic impedance of the line suddenly changes discontinuously, signal reflection occurs and propagation is hindered. Therefore, according to this filter element, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise.

  Further, according to the filter element of the fifth aspect, the signal conductor, the grounding conductor, and the strip-shaped insulator are wound so that the grounding conductor is located inside the signal conductor, so that the cylinder as a whole is wound. The coil part is formed in the shape, the input part is defined on the inner periphery of the signal conductor, the output part is defined on the outer periphery of the signal conductor, and the ground part is defined on the inner periphery of the grounding conductor. Then, by winding the sheet conductor in a floating state so as to face the signal conductor, the sheet conductor forms a capacitance component between the signal strip conductors. For this reason, since the characteristic impedance of the line suddenly changes discontinuously, signal reflection occurs and propagation is hindered. Therefore, according to this filter element, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise.

  According to the filter element of claim 6, one part of the grounding strip-like conductor is separated from the other part, and the sheet-like conductor is constituted by the separated part, whereby the grounding conductor As compared with a configuration in which a separate sheet-like conductor is wound around the coil portion via the belt-like insulator, the coil portion can be formed with a smaller diameter, so that the filter element can be reduced in size.

  According to the filter element of claim 7, the grounding part is located on the opposite side of the input part across the center of the coil part, and the input part is sandwiched across the center of the coil part. By positioning the output part on the opposite side, a large attenuation can be ensured in a predetermined frequency band, so that a filter element having excellent attenuation characteristics can be realized.

  According to the filter element of claim 8, the grounding part is located on the opposite side of the input part across the center of the coil part, and the grounding part is sandwiched across the center of the coil part. By positioning the output part on the opposite side, a large attenuation can be ensured in a predetermined frequency band, so that a filter element having excellent attenuation characteristics can be realized.

  According to the filter element of the ninth 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.

  According to the filter element of claim 10, each terminal is used by connecting an input terminal to the input part, connecting an output terminal to the output part, and connecting a grounding terminal to the ground part. Thus, the filter element can be easily mounted on a power supply device or the like.

  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 a pair of input terminals 2a and 2b (hereinafter also referred to as “input terminal 2” unless otherwise specified) and a pair of output terminals 3a and 3b (hereinafter referred to as “not particularly distinguished”. Output terminal 3 ”), grounding terminal 4, coil portion 5, and columnar (columnar as an example) magnetic body (magnetic core) 6, and a distributed constant type noise filter (low-pass type) Function as a common mode filter.

  As shown in FIG. 3, the coil portion 5 includes strip-shaped insulators 7a and 7b, a ground strip-shaped conductor 8 formed narrower than the strip-shaped insulators 7a and 7b, a pair of signal strip-shaped conductors 9a, 9b and the sheet-like conductor 10 are provided. In this case, the strip insulators 7a and 7b are formed to have the same width, the same length, and the same thickness by using, for example, a dielectric and electrical insulating material (polyimide, polyethylene, insulating paper, etc.). Has been. A grounding belt-like conductor (hereinafter also referred to as “grounding conductor”) 8 is grounded to a grounding portion C defined on one end side which is the outermost peripheral portion (the left end side in the figure which is the winding end end side). One end side of the service terminal 4 is electrically connected (hereinafter also simply referred to as “connection”). The grounding conductor 8 is formed in a band shape (long rectangle) slightly narrower than the band-shaped insulator 7a and slightly shorter than the band-shaped insulator 7a, and is superimposed on the band-shaped insulator 7a. ing. In addition, the grounding conductor 8 is separated (divided) from other parts at the other end side (the end on the same side as the end to which each output terminal 3 of each signal conductor 9 is connected). ing. The sheet-like conductor 10 in the present invention is formed by the separated other end side (winding start end side) portion (one portion in the present invention) of the grounding conductor 8. In this case, when the length L1 of the grounding conductor 8 before separation is 1, the sheet-like conductor 10 has a range of 0.3 to 0.7, preferably 0.5 ± 0.05. The length L2 is defined so that The strip insulator 7b is superimposed on the strip insulator 7a so as to sandwich the grounding conductor 8 and the sheet conductor 10 between the strip insulator 7a.

  Each of the signal strip conductors 9a and 9b (hereinafter also referred to as “signal conductors 9a and 9b”, and also referred to as “signal conductor 9” unless otherwise specified) has, for example, the same width and the same length. And the same thickness. Further, as shown in FIG. 3, each of the signal conductors 9a and 9b is provided at an input site A defined on one end side (the left end side in the figure which is the winding end side) which is the outermost peripheral portion. One end side of each of the input terminals 2a and 2b is connected, and each output terminal 3a is connected to an output portion B defined on the other end side (the right end side in the figure which is the winding start end side) which is the innermost peripheral portion. , 3b are respectively connected to one end side. The signal conductors 9a and 9b are arranged side by side on the strip insulator 7b in parallel with the length direction of the strip insulator 7b and in a non-contact state with each other.

  As shown in FIG. 3, each coil-shaped insulator 7 and each conductor 8, 9 and 10 stacked on each other as shown by arrows in FIG. The other end side (the right end side in the figure) is started to be wound, and the grounding conductor 8 and the sheet-like conductor 10 are wound around the signal conductors 9 so as to be outside, As shown in FIG. 1, it is formed in a cylindrical shape as a whole (a cylindrical shape in which a gap H is formed in the center). In this case, the sheet-like conductor 10 is separated from the grounding conductor 8 and is sandwiched between the strip-like insulators 7a and 7b, so that it is not in contact with any terminal and any conductor, in other words, In other words, it is in an electrically insulated state (floating state in the present invention) and is opposed to each signal conductor 9 (specifically, on the output portion side of the signal conductor 9) via the strip insulator 7b. Is wound in the coil portion 5. 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 each signal conductor 9 is the outer peripheral part of the coil part 5 as shown in FIG. 2 when the coil part 5 is viewed from one end face (upper end face in FIG. 1) side. Is located in each. Moreover, each input terminal 2 connected to the input part A of each signal conductor 9 is connected to the other end from the outer peripheral part on one end face (upper end face in the figure) of the coil part 5 as shown in FIG. 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 input site | part A of each signal conductor 9 and the extraction | drawer site | part of each input terminal 2 correspond substantially. Therefore, in the following, the drawing portion of each 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 side, the output part B of each signal conductor 9 is located at the inner peripheral part of the coil part 5 as shown in FIG. Further, each output terminal 3 connected to the output part B of each signal conductor 9 is drawn out from the inner peripheral part of one end face of the coil part 5 as shown in FIG. 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 each signal conductor 9 and the extraction | drawer site | part of each output terminal 3 correspond substantially. Therefore, hereinafter, the lead-out site of each output terminal 3 is also referred to as “draw-out site B”. Here, as shown in FIG. 2, the output part B of each signal conductor 9 (that is, the lead-out part of the output terminal 3) is connected to the central axis O of the coil portion 5 and the input part A of each signal conductor 9 ( That is, on the virtual plane L (hereinafter also referred to as “plane L”) including the input terminal 2 lead portion), on the opposite side of the input portion A across the central axis O (or the magnetic core 6). Is set. 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 side. Further, as shown in FIG. 1, the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 has the other end drawn from the outer peripheral part of one end face of the coil part 5. 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”. Further, 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 center axis O of the coil portion 5. Here, the “drawer part” of the input terminal 2 or the like in the present invention 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. Further, the “innermost peripheral portion” refers to a portion included in one turn of the winding in the signal conductor 9 or the grounding conductor 8, and the “outermost peripheral portion” refers to the signal conductor 9 or the grounding. This refers to a portion included in one turn at the end of winding in the electrical conductor 8.

  In this filter element 1, the conductors 8, 9, 10 and the strip insulators 7 a, 7 b are wound so that the grounding conductor 8 is outside the signal conductor 9, thereby forming a tubular shape as a whole. A coil portion 5 is formed, an output portion B is defined on the innermost peripheral portion of each signal conductor 9, and an input portion A is defined on the outermost peripheral portion of each signal conductor 9. By defining the grounding part C at the outermost peripheral portion and winding the sheet-like conductor 10 in a floating state so as to face the signal conductors 9, the sheet-like conductor 10 becomes each signal-band conductor. A capacitance component is formed between the nine. For this reason, since the characteristic impedance of the line suddenly changes discontinuously, signal reflection occurs and propagation is hindered. For this reason, according to the filter element 1, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise while maintaining the attenuation characteristic with respect to the common mode noise in a good state.

  Further, according to the filter element 1, the coil portion 5 is formed with the grounding conductor 8 outside the signal conductor 9, and the input portion A (each input terminal 2 of the signal conductor 9 is formed). ), The output part B of the signal conductor 9 (the extraction part of each output terminal 3), and the position of the grounding part C of the grounding conductor 8 (the extraction part of the grounding terminal 4) as described above. As a result, a large attenuation amount can be ensured in a predetermined frequency band, so that a common mode filter element having excellent attenuation characteristics can be realized. Moreover, according to this filter element 1, while separating the site | part (one site | part in this invention) of the other end side in the conductor 8 for grounding from the other site | part, the sheet-like conductor 10 is comprised by this isolate | separated site | part. As a result, the coil part 5 can be formed to have a smaller diameter compared to the configuration in which the grounding conductor 8 and the sheet-like conductor 10 that are separate from the grounding conductor 8 are wound around the coil part 5 via the belt-like insulator. The filter element 1 can be miniaturized. Further, according to the filter element 1, each input terminal 2 is connected to each input part A, each output terminal 3 is connected to each output part B, and the grounding terminal 4 is connected to the ground part C. Using the terminals 2, 3 and 4, the filter element 1 can be easily mounted on a power supply device or the like.

(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 a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, a grounding terminal 4, a coil portion 25, and a magnetic core 6, and is distributed constant type. It functions as a noise filter (low-pass common mode filter).

  As shown in FIG. 6, the coil portion 25 includes strip-shaped insulators 7 a and 7 b, a ground strip-shaped conductor 8, signal strip-shaped conductors 9 a and 9 b, and a sheet-shaped conductor 10. In this case, each signal conductor 9 has one end side of each output terminal 3 connected to an output portion B defined on one end side (the right end side in the figure which is the winding end end side) which is the outermost peripheral portion. At the same time, one end side of each input terminal 2 is connected to an input portion A defined on the other end side (the left end side in the figure which is the winding start end side) which is the innermost peripheral portion. The signal conductors 9 are arranged on the strip insulator 7a so as to be parallel to the length direction of the strip insulator 7a and in a non-contact state with each other. The strip insulator 7b is overlaid on the strip insulator 7a so that each signal conductor 9 is sandwiched between the strip insulator 7a. The grounding conductor 8 is in a state where one end side of the grounding terminal 4 is connected to the grounding portion C defined on the other end side (the left end side in the figure which is the winding start end side) which is the innermost peripheral portion. , Is overlaid on the strip insulator 7b. Also, the grounding conductor 8 is separated (divided) from other parts at one end (the same end as the one end of each signal conductor 9 where the output part B is defined). ing. The sheet-like conductor 10 is formed by this separated one end side (winding end side) portion (one portion in the present invention) of the grounding conductor 8.

  As shown in FIG. 6, the coil portion 25 is configured so that the band-like insulators 7 and the conductors 8, 9, and 10 overlapped with each other as described above are connected to the other ends ( As shown in FIG. 4, by winding the signal conductor 9 to the outside with respect to the grounding conductor 8, starting from the left end side in FIG. It is formed in the cylindrical shape formed. In this case, the sheet-like conductor 10 is separated from the grounding conductor 8 and is sandwiched between the strip-like insulators 7a and 7b, so that it is in a non-contact state with any of the terminals and any of the conductors (floating). And in the state of being opposed to each signal conductor 9 (specifically, the output portion side of the signal conductor 9) via the belt-like insulator 7b. A magnetic core 6 is mounted in the gap H of the coil portion 25.

  In this case, the input portion A of each signal conductor 9 has an inner peripheral side of the coil portion 25 as shown in FIG. 5 when the coil portion 25 is viewed from one end surface (upper end surface in FIG. 4) side. It is located in each part. Each input terminal 2 connected to the input part A of each signal conductor 9 is connected to the other part from the inner peripheral part on one end face (upper end face in the figure) of the coil portion 25 as shown in FIG. The end 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 each signal conductor 9 and the extraction | drawer site | part of each input terminal 2 correspond substantially. Therefore, in the following, the drawing portion of each input terminal 2 is also referred to as “drawing portion A”. On the other hand, the output part B of each 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 side. Further, each output terminal 3 connected to the output part B of each signal conductor 9 has its other end drawn from the outer peripheral part of one end face of the coil portion 25 as shown in FIG. 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 each signal conductor 9 and the extraction | drawer site | part of each output terminal 3 correspond substantially. Therefore, hereinafter, the lead-out site of each output terminal 3 is also referred to as “draw-out site B”. Here, the output part B of each 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 each signal conductor 9 ( That is, it is set on the plane L including the lead-out part of the input terminal 2 and on the opposite side to the input part A across the central axis O (or the magnetic core 6). Further, the grounding portion C of the grounding conductor 8 is located at the inner peripheral side portion of the coil portion 25 as shown in FIG. 5 when the coil portion 25 is viewed from one end face side. Further, as shown in FIG. 4, the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 has the other end drawn from the inner peripheral part of one end face of the coil portion 25. 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”. Here, as shown in FIG. 5, the grounding portion C of the grounding conductor 8 is set on the plane L and opposite to the input portion A across the central axis O of the coil portion 25. Yes.

  In this filter element 21, the conductors 8, 9, 10 and the strip insulators 7 a, 7 b are wound so that the grounding conductor 8 is inside the signal conductor 9, so that the whole is cylindrical. A coil portion 25 is formed on the outermost peripheral portion of each signal conductor 9, an output portion B is defined on the innermost peripheral portion of each signal conductor 9, and an input portion A is defined on the innermost peripheral portion of each signal conductor 9. By defining the grounding portion C in the innermost periphery of the sheet and winding the sheet-like conductor 10 in a floating state so as to face the signal conductors 9, the sheet-like conductor 10 is made to have a signal-like band conductor. A capacitive component is formed between the bodies 9. For this reason, since the characteristic impedance of the line suddenly changes discontinuously, signal reflection occurs and propagation is hindered. For this reason, according to the filter element 21, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise while maintaining the attenuation characteristic with respect to the common mode noise in a good state.

  Further, according to the filter element 21, the coil portion 25 is formed with the grounding conductor 8 inside the signal conductor 9, and the input portion A (each input terminal 2 of the signal conductor 9). ), The output part B of the signal conductor 9 (the extraction part of each output terminal 3), and the position of the grounding part C of the grounding conductor 8 (the extraction part of the grounding terminal 4) as described above. As a result, a large attenuation amount can be ensured in a predetermined frequency band, so that a common mode filter element having excellent attenuation characteristics can be realized. Further, according to the filter element 21, in the same manner as the filter element 1, the part on one end side of the grounding conductor 8 is separated from other parts, and the sheet-like conductor 10 is configured by the separated part. As a result, the coil portion 25 can be formed to have a smaller diameter as compared with the configuration in which the grounding conductor 8 and the separate sheet-like conductor 10 are wound around the coil portion 25 via the belt-like insulator. The element 21 can be miniaturized. Further, according to this filter element 21, in the same manner as the filter element 1, each input terminal 2, each output terminal 3, and grounding terminal 4 are connected to each part A, B, C. 3 and 4 can be used to easily mount the filter element 21 on a power supply device or the like.

  The present invention is not limited to the configuration described above. For example, in each of the filter elements 1 and 21 described above, as shown in FIGS. 3 and 6, one grounding conductor 8 and one sheet-like conductor 10 are connected to each signal conductor 9 as a strip-like insulator 7b. However, like the filter elements 31 and 41 shown in FIGS. 7 and 8, the grounding conductor 8 and the sheet-like conductor 10 are individually provided for each of the signal conductors 9a and 9b. It can also be arranged. Hereinafter, each filter element 31 and 41 is demonstrated concretely.

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

  First, the configuration of the filter element 31 will be described. The filter element 31 is configured by increasing the grounding conductor 8 to two corresponding to each signal conductor 9 while using the filter element 1 as a basis. For this reason, many of the components of the filter element 31 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. 1, the filter element 31 includes a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, a grounding terminal 4, a coil portion 35, and a magnetic core 6, and is a distributed constant type. It functions as a noise filter (low-pass common mode filter).

  As shown in FIG. 7, the coil portion 35 includes strip-shaped insulators 7a and 7b, a pair of grounding strip-shaped conductors 8a and 8b (hereinafter also referred to as “grounding conductor 8” unless otherwise distinguished), and a pair of signals. The belt-like conductors 9a and 9b and a pair of sheet-like conductors 10a and 10b (hereinafter also referred to as “sheet-like conductor 10” unless otherwise specified) are configured. In this case, each of the grounding conductors 8a and 8b has one end side of the grounding terminal 4 connected to the grounding portion C defined on each one end side (winding end side) which is the outermost peripheral portion, and is not mutually connected. In contact, parallel to the length direction of the strip-shaped insulator 7a, and overlaid on the strip-shaped insulator 7a so as to face each other via the corresponding signal conductors 9a, 9b and the strip-shaped insulator 7b. ing. Further, each grounding conductor 8 is separated (divided) from the other end side (the end on the same side as the end to which each output terminal 3 in each signal conductor 9 is connected). Has been. Each of the sheet-like conductors 10a and 10b is formed by each of the separated other end sides (winding start end sides) of the grounding conductors 8a and 8b.

  In addition, the coil portion 35 connects each strip insulator 7 and each conductor 8, 9, 10 to the other end side of each strip insulator 7 and each signal conductor 9 (same as shown by arrows in FIG. 7). As shown in FIG. 1, winding is performed so that the grounding conductor 8 and the sheet-like conductor 10 are on the outside of each signal conductor 9, starting from the right end side in the drawing). The whole is formed in a cylindrical shape. In this case, each sheet-like conductor 10 is separated from each grounding conductor 8 and is sandwiched between the strip-like insulators 7a and 7b so that it is not in contact with any terminal or any conductor. It is wound in the coil portion 35 in a state of being in a floating state and facing each signal conductor 9 (specifically, the output portion B side of the signal conductor 9) via the strip insulator 7b. . In this case, the input part A of the signal conductor 9 (the lead part of each input terminal 2), the output part B of the signal conductor 9 (the lead part of each output terminal 3), and the ground part of the grounding conductor 8 C (drawing part of each grounding terminal 4) is set at the position shown in FIG.

(4th best form)
Next, the filter element 41 according to this 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 by increasing the grounding conductor 8 to two corresponding to each signal conductor 9 while using the filter element 21 as a basis. For this reason, many of the components of the filter element 41 are common to the components of the filter element 21. Therefore, the same components as those of the filter element 21 are denoted by the same reference numerals, and redundant description is omitted.

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

  As shown in FIG. 8, the coil portion 45 includes strip insulators 7a and 7b, a pair of ground strip conductors 8a and 8b, a pair of signal strip conductors 9a and 9b, and a pair of sheet conductors 10a, 10b. In this case, each of the grounding conductors 8a and 8b has one end side of the grounding terminal 4 connected to the grounding portion C defined on each other end side (winding start end side) serving as the innermost periphery, and Arranged on the strip-like insulator 7b so as to face each other via the strip-like insulator 7b in parallel with the corresponding length of the signal conductors 9a, 9b in a non-contact state with each other. It is piled up. In addition, each grounding conductor 8 is separated (divided) from other parts at one end side (the end on the same side as the output part in each signal conductor 9). Each of the sheet-like conductors 10a and 10b is formed by each of the separated one end side (winding end end side) portions of the respective grounding conductors 8a and 8b.

  In addition, the coil portion 45 connects each strip insulator 7 and each conductor 8, 9, 10 to the other end side of each strip insulator 7 and each signal conductor 9 as shown by arrows in FIG. As shown in FIG. 4, winding is performed so that the grounding conductor 8 and the sheet-like conductor 10 are inside each signal conductor 9, starting from the left end side in the figure). The whole is formed in a cylindrical shape. In this case, each sheet-like conductor 10 is separated from each grounding conductor 8 and is sandwiched between the strip-like insulators 7a and 7b so that it is not in contact with any terminal or any conductor. It is wound in the coil portion 45 in a state of being in a floating state and facing each signal conductor 9 (specifically, the output portion B side of the signal conductor 9) via the strip-shaped insulator 7b. . In this case, the input part A of the signal conductor 9 (the lead part of each input terminal 2), the output part B of the signal conductor 9 (the lead part of each output terminal 3), and the ground part of the grounding conductor 8 C (drawing site of each grounding terminal 4) is set at a position shown in FIG.

  According to the filter elements 31 and 41, the coil portions 35 and 45 are formed by winding the sheet-like conductors 10a and 10b in a floating state so as to face the signal conductors 9a and 9b. Similarly to the filter elements 1 and 21, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise while maintaining the attenuation characteristic with respect to the common mode noise in a good state. Similarly to the filter elements 1 and 21, the coil conductors 35 and 45 are formed with the grounding conductors 8 being outside or inside the signal conductors 9, and the signal conductors 9 Input part A (drawing part of each input terminal 2), output part B of signal conductor 9 (drawing part of each output terminal 3), and grounding part C of grounding conductor 8 (drawing part of grounding terminal 4) ) Is defined, a large attenuation amount can be ensured in a predetermined frequency band. As a result, a common mode filter element having excellent attenuation characteristics can be realized. Further, according to the filter elements 31 and 41, similarly to the filter elements 1 and 21, one part of the grounding conductor 8 (the end on the same side as the output part B in each signal conductor 9) is provided. By configuring the sheet-like conductor 10 separately from other parts, the coil portions 35 and 45 can be formed with a smaller diameter, and as a result, the overall size can be reduced. Further, according to the filter elements 31 and 41, the pair of sheet conductors 10a and 10b are provided so as to face the signal conductors 9a and 9b, respectively. In addition, since it is not necessary to dispose the conductor in a portion not facing the signal conductors 9a and 9b (a portion facing the region sandwiched between the sheet-like conductors 10a and 10b), the minimum necessary conductivity Each sheet-like conductor 10 can be formed of a body. Therefore, according to each filter element 31 and 41, the weight reduction of a filter element can be achieved. Further, according to the filter elements 31 and 41, the input terminals 2, the output terminals 3 and the grounding terminals 4 are connected to the parts A, B and C in the same manner as the filter elements 1 and 21, respectively. The filter elements 31, 41 can be easily mounted on a power supply device or the like using the terminals 2, 3, 4.

  The present invention is not limited to the configuration described above. For example, in each of the filter elements 1, 21, 31, and 41 described above, the lead-out portion B of each output terminal 3 is opposite to each input terminal 2 across the central axis O as shown in FIGS. However, like the filter elements 51 and 61 shown in FIGS. 9 and 11, the lead-out portion of each output terminal 3 is positioned on the same side as each input terminal 2 with respect to the central axis O. B can also be defined. Hereinafter, the filter elements 51 and 61 will be specifically described.

(5th best form)
First, the filter element 51 according to the present embodiment will be described with reference to FIGS. The filter element 51 has the same configuration as that of the filter element 1 except for the arrangement of the output part B (the lead-out part for each output terminal 3). Thus, redundant description is omitted.

  As shown in FIG. 9, the filter element 51 includes a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, a grounding terminal 4, a coil portion 55, and a magnetic core 6, and is distributed constant type. It functions as a noise filter (low-pass common mode filter). In this case, as shown in FIG. 3, the coil portion 55 includes the same components as the coil portion 5 of the filter element 1, and in the same manner as the coil portion 5, the strip insulators 7 and the conductive layers that are overlapped with each other. By winding the bodies 8, 9, and 10, as shown in FIG.

  In this case, the other end side of the grounding terminal 4 connected to the grounding part C of the grounding conductor 8 is drawn from the outer peripheral part of one end face of the coil part 55 as shown in FIG. Further, when the coil portion 55 is viewed from one end surface (upper end surface in FIG. 9) side of the coil terminal 55 as shown in FIG. It is located at the outer periphery side part. On the other hand, each input terminal 2 connected to the input part A of each signal conductor 9 has its other end drawn from the outer peripheral part of one end face of the coil portion 55 as shown in FIG. Further, the drawing position of each input terminal 2 (the position of the input part A) is as shown in FIG. 10 when the coil part 55 is viewed from one end face (upper end face in FIG. 9) side. Are set on the plane L including the central axis O and the input part A and on the opposite side to the grounding part C across the central axis O (or the magnetic core 6). As shown in FIG. 9, each output terminal 3 connected to the output part B of each signal conductor 9 is led out from the inner peripheral part on one end face of the coil portion 55. Further, the drawing position of each output terminal 3 (position of the output part B) is on the plane L as shown in FIG. 10 when the coil portion 55 is viewed from one end face (upper end face in FIG. 9) side. In this case, the center axis O (or the magnetic core 6) is set on the opposite side to the grounding portion C. That is, each output terminal 3 is drawn from the same side as each input terminal 2 with the central axis O as a reference.

(Sixth best mode)
Next, the filter element 61 according to this embodiment will be described with reference to FIGS. The filter element 61 has the same configuration as the filter element 21 except for the arrangement of the output part B (the lead part for each output terminal 3). Thus, redundant description is omitted.

  As shown in FIG. 11, the filter element 61 includes a pair of input terminals 2a and 2b, a pair of output terminals 3a and 3b, a grounding terminal 4, a coil portion 65, and a magnetic core 6, and is distributed constant type. It functions as a noise filter (low-pass common mode filter). In this case, as shown in FIG. 6, the coil portion 65 includes the same constituent elements as the coil portion 25 of the filter element 21, and in the same manner as the coil portion 25, the strip insulators 7 and the conductive layers stacked on each other. By winding the bodies 8, 9, and 10, as shown in FIG.

  In this case, the grounding terminal 4 connected to the grounding portion C of the grounding conductor 8 has the other end drawn from the inner peripheral side portion of one end face of the coil portion 65 as shown in FIG. Further, the drawing position of the grounding terminal 4 (the position of the grounding portion C) is such that when the coil part 65 is viewed from one end face (upper end face in FIG. 11) side, as shown in FIG. Located on the inner periphery. On the other hand, each input terminal 2 connected to the input part A of each signal conductor 9 has its other end drawn from the inner peripheral part of one end face of the coil portion 65 as shown in FIG. Further, as shown in FIG. 12, when the coil portion 65 is viewed from one end face side, the drawing position of each input terminal 2 (the position of the input portion A) is the same as the central axis O of the coil portion 65 and the input portion A. On the plane L including the center axis O (or the magnetic core 6). As shown in FIG. 11, each output terminal 3 connected to the output part B of each signal conductor 9 is led out from the outer peripheral side part on one end face of the coil portion 55. Further, the drawing position of each output terminal 3 (the position of the output part B) is on the plane L as shown in FIG. Alternatively, the magnetic core 6) is set on the opposite side with respect to the grounding portion C. That is, each output terminal 3 is drawn from the same side as each input terminal 2 with the central axis O as a reference.

  According to each of the filter elements 51 and 61, the coil portions 55 and 65 are formed by winding the sheet-like conductor 10 in a floating state so as to face the signal conductors 9a and 9b. Similarly to the elements 1 and 21, it is possible to improve the attenuation characteristic by increasing the attenuation gradient in the vicinity of the cutoff frequency with respect to the normal mode noise while maintaining the attenuation characteristic with respect to the common mode noise in a good state. In addition, the coil conductors 55 and 65 are formed with the respective grounding conductors 8 on the outside or the inside with respect to the signal conductors 9, and the input portion A of the signal conductor 9 (the lead-out portion of each input terminal 2). ), The positions of the output part B of the signal conductor 9 (the lead part of each output terminal 3) and the ground part C of the grounding conductor 8 (the lead part of the grounding terminal 4) are defined as described above. As a result, a large attenuation amount can be ensured in a predetermined frequency band, so that a common mode filter element having excellent attenuation characteristics can be realized. Further, according to the filter elements 51 and 61, similarly to the filter elements 1 and 21, one part of the grounding conductor 8 (the end on the same side as the output part B in each signal conductor 9) is provided. Since the sheet-like conductor 10 is configured separately from other portions, the coil portions 55 and 55 can be formed with a smaller diameter, and as a result, the overall size can be reduced. Further, according to the filter elements 51 and 61, in the same manner as the filter elements 1 and 21, the input terminals 2, the output terminals 3 and the grounding terminals 4 are connected to the parts A, B and C, respectively. The filter elements 51 and 61 can be easily mounted on a power supply device or the like using the terminals 2, 3 and 4.

  The present invention is not limited to the configuration described above. For example, the configuration of each of the above-described common mode filter elements 1, 21, 31, 41, 51, 61, that is, the configuration in which the sheet-like conductor 10 is wound in a floating state to form a coil portion, the normal mode filter By applying to an element, a low-pass normal mode filter having excellent attenuation characteristics can be realized. Hereinafter, as an example, a normal mode filter element to which the configuration of the filter elements 1 and 21 is applied will be described in detail.

(Seventh best mode)
A filter element 71 according to this embodiment will be described with reference to FIGS. The filter element 71 is a normal mode filter configured using the configuration of the filter element 1. For this reason, many of the components of the filter element 71 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. 13, the filter element 71 includes one input terminal 2, one output terminal 3, one ground terminal 4, a coil unit 75, and a magnetic core 6, and is distributed noise type. Functions as a filter (low-pass normal mode filter).

  As shown in FIG. 14, the coil portion 75 includes strip-shaped insulators 7 a and 7 b, a grounding conductor 8, a single signal conductor 9, and a sheet-like conductor 10. Specifically, the coil portion 75 is equivalent to a configuration in which, for example, the input terminal 2b, the output terminal 3b, and the signal conductor 9b are omitted from the configuration of the coil portion 5, and the signal conductor 9a is changed to be wider. It has the composition of. Further, the input part A of the signal conductor 9 to which the input terminal 2 is connected, the output part B of the signal conductor 9 to which the output terminal 3 is connected, and the grounding terminal to which the grounding terminal 4 is connected. The grounding portion C of the conductor 8 is defined at the same position as the filter element 1 as shown in FIG.

(Eighth best mode)
Subsequently, the filter element 81 according to the present embodiment will be described with reference to FIGS. The filter element 81 is a normal mode filter configured using the configuration of the filter element 21. For this reason, many of the components of the filter element 81 are common to the components of the filter element 21. Therefore, the same components as those of the filter element 21 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 15, the filter element 81 includes one input terminal 2, one output terminal 3, one ground terminal 4, a coil unit 85, and a magnetic core 6, and is distributed noise type. Functions as a filter (low-pass normal mode filter).

  As shown in FIG. 16, the coil portion 85 includes strip-shaped insulators 7 a and 7 b, a grounding conductor 8, a single signal conductor 9, and a sheet-like conductor 10. Specifically, the coil unit 85 has the same configuration as the configuration of the coil unit 25 except that, for example, the input terminal 2b, the output terminal 3b, and the signal conductor 9b are omitted, and the signal conductor 9a is changed to be wider. It has a configuration. Further, the input part A of the signal conductor 9 to which the input terminal 2 is connected, the output part B of the signal conductor 9 to which the output terminal 3 is connected, and the grounding terminal to which the grounding terminal 4 is connected. The grounding portion C of the conductor 8 is defined at the same position as the filter element 21 as shown in FIG.

  The normal mode filter elements 71 and 81 to which the configurations of the filter elements 1 and 21 are applied have been described above. However, in the same manner as the filter elements 71 and 81, the filter elements 51 and 61 are used as a base, and FIG. As shown in FIG. 18, the filter elements 91 and 101 for the normal mode in which the positions of the output part B (the lead-out part of the output terminal 3) in the coil portions 95 and 105 are defined as shown in FIGS. You can also. According to each of the filter elements 71, 81, 91, 101 described above, the normal mode noise is improved in the same way that the attenuation characteristics with respect to the normal mode noise can be improved in the corresponding common mode filter elements 1, 21, 51, 61. It is possible to improve the attenuation characteristics by increasing the attenuation gradient in the vicinity of the cutoff frequency. Further, according to each filter element 71, 81, 91, 101, the coil portions 75, 85, 95, 105 are formed with the grounding conductor 8 outside or inside with respect to the signal conductor 9, The input part A of the 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 (the ground terminal 4) of the grounding conductor 8 In the same manner as the corresponding common mode filter elements 1, 21, 51, 61, it is possible to secure a large amount of attenuation in a predetermined frequency band. As a result, a normal mode filter element having excellent attenuation characteristics can be realized.

  The present invention is not limited to the configuration described above. For example, in each of the filter elements 1, 21, 31,..., 101 described above, a rod-like conductor is used as a terminal such as the input terminal 2, the output terminal 3, and the grounding terminal 4, and input / output of ground and signals. However, it is also possible to use a flexible wiring cable. Further, in each of the filter elements 1, 21, 31,..., 101 described above, the magnetic core 6 is mounted inside the gap H formed in each coil portion 5, 25, 35,. Although the example in which the attenuation characteristic is improved by improving the degree of coupling of the conductor 8 and the signal conductor 9 and the value of the distributed inductance has been described, the coil portions 5, 25, 35 are included in the pot core instead of the magnetic core 6. ,..., 105 can be used. According to this configuration, the pot core can provide a closed magnetic circuit structure, and the degree of coupling between the grounding conductor 8 and the signal conductor 9 and the value of the distributed inductance are further improved, while the coil portions 5 and 25 of the external magnetic field are provided. , 35,... 105 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 a magnetic body inside the space | gap H formed in the coil parts 5, 25, 35, ..., 105 can also be employ | adopted.

  Further, in each of the filter elements 1, 21, 31,..., 101 described above, the input terminal 2, the output terminal 3, and the grounding terminal 4 are connected to the same end face (FIGS. 1, 4, 9, 11, 13,. 15, 17, and 18, only the upper end surface is employed. However, the input terminal 2, the output terminal 3, and the grounding terminal 4 are disposed on a plane L including the central axis O of the coil portion. Therefore, a configuration is adopted in which some of the input terminal 2, the output terminal 3 and the grounding terminal 4 are arranged on the end surface opposite to the other terminals (for example, the lower end surface in FIG. 1). You can also. In each of the filter elements 1, 21, 31,..., 101 described above, the input terminal 2, the output terminal 3, and the grounding terminal 4 are arranged on the plane L including the central axis O of the coil portion. Although adopted, all the terminals may not be strictly arranged on the plane L, and each terminal may be arranged at a position slightly deviated from the plane L. In this case, although the attenuation characteristics are slightly lower than those of the filter elements 1, 21, 31,..., 101, the attenuation characteristics are still sufficiently good as compared with the conventional filter elements. In other words, by disposing the input terminal 2, the output terminal 3, and the grounding terminal 4 on the plane L including the central axis O of the coil portion, it is possible to secure a larger attenuation in a predetermined frequency band. As a result, it is possible to realize a common mode or normal mode filter element having the best attenuation characteristics. Further, in each of the filter elements 1, 21, 31,..., 101 described above, the sheet conductor 10 is configured by separating the other end portion of the grounding conductor 8 from the other portions. A sheet-like conductor 10 separate from the conductor 8 can be wound around the coil portions 5, 25, 35,. In addition, the number of signal conductors is not limited to one and two, and can be three or more. In this configuration, the same number of sheet conductors as the signal conductors are connected to each signal conductor. It is arranged in a floating state so as to face the body. In each of the filter elements 1, 21, 31,..., 101 described above, the input terminal 2, the output terminal 3, and the grounding terminal 4 are connected to the innermost circumference of the corresponding signal conductor 9 and grounding conductor 8. Connected to the part (part included in one turn at the beginning of winding) or the outermost peripheral part (part included in one turn at the end of winding), but the part connecting each terminal is not limited to this, for example, The signal conductor 9 and the grounding conductor 8 can be connected to the inner peripheral portion (a portion included in the first turn of the winding) or the outer peripheral portion (a portion included in the first turn of the winding).

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

(Example 1, Comparative Example 1)
A grounding conductor 8 (including the sheet-like conductor 10) having a width of 11 mm, a pair of signal conductors 9a and 9b having a width of 3 mm and the same length as the grounding conductor 8, and a thickness Using a pair of strip-like insulators 7a and 7b formed of a polyimide insulating sheet having a thickness of 50 μm, the grounding conductor 8 is outside the signal conductors 9a and 9b, and the number of turns is 35 turns. Example 1 corresponding to the filter element 1 was prepared by attaching the produced coil part 5 to an EI type core. In this case, when the length of the signal conductors 9a and 9b (same as the length of the ground conductor 8 before the division) is 1, the lengths of the ground conductor 8 and the sheet-like conductor 10 are respectively It was defined as about 0.5.

  In the configuration of the first embodiment, the grounding conductor 8 is not divided (in other words, the sheet-like conductor 10 is not formed), and the length of the grounding conductor 8 is set to each signal conductor 9a. , 9b, the number of turns of each conductor 8, 9a, 9b is defined to be the same as that of the coil portion 35 to form a coil portion, and the same core is attached to correspond to the filter element 1. It was set as Comparative Example 1.

  Next, attenuation characteristics (normal mode characteristics and common mode characteristics) of the filter elements according to Example 1 and Comparative Example 1 were measured using the software fixture function of NETWORK ANALYZER R3767CG manufactured by ADVANTEST. In this case, in the measurement of the normal mode characteristics, a method of simultaneously supplying test signals whose phases are reversed to the input terminals 2a and 2b was adopted. On the other hand, in the measurement of the common mode characteristics, the pair of input terminals 2a and 2b are short-circuited and the pair of output terminals 3a and 3b are short-circuited to simultaneously supply test signals to the signal conductors 9a and 9b. The method to do was adopted. FIG. 19 shows the attenuation characteristics for the normal mode of the filter elements according to Example 1 and Comparative Example 1, and FIG. 20 shows the attenuation characteristics for the common mode. In addition, in each figure, the attenuation | damping characteristic of the filter element 1 which concerns on Example 1 is shown with the code | symbol P, and the attenuation | damping characteristic of the filter element which concerns on the comparative example 1 is shown with the code | symbol Q.

  According to FIG. 19, regarding the attenuation characteristics related to the normal mode, the filter element 1 according to Example 1 can flatten the passband (low frequency band) and the cutoff frequency compared to the filter element according to Comparative Example 1. It was confirmed that the attenuation gradient in the vicinity can be increased. Further, it was confirmed that the maximum attenuation can be increased in the filter element 1 according to Example 1.

  On the other hand, according to FIG. 20, with respect to the attenuation characteristics related to the common mode, the attenuation amount of the filter element 1 according to Example 1 is generally within the range of 2 dB to 5 dB as compared with the filter element according to Comparative Example 1. Although it is decreasing, it was confirmed that the amount of decrease was suppressed to the minimum, and the necessary attenuation could be secured.

It is a perspective view which shows the structure of the filter element 1 (31). A plane of the filter element 1 (31, 71) viewed from one end face for indicating the positions of the input part A and the output part B in the signal conductor 9 and the position of the ground part C in the grounding conductor 8 FIG. In order to show the structure of the filter element 1 (51), it is the perspective view of the state which unwinded the coil part 5 (55). It is a perspective view which shows the structure of the filter element 21 (41). A plane of the filter element 21 (41, 81) viewed from one end face for indicating the positions of the input part A and the output part B in the signal conductor 9 and the position of the ground part C in the grounding conductor 8 FIG. In order to show the structure of the filter element 21 (61), it is the perspective view of the state which unwound the coil part 25 (65). FIG. 3 is a perspective view of a state in which a coil portion 35 is unrolled to show the configuration of the filter element 31. FIG. 3 is a perspective view of a state in which a coil portion 45 is unrolled to show the configuration of the filter element 41. 3 is a perspective view showing a configuration of a filter element 51. FIG. The top view which looked at the filter element 51 (91) for showing each position of the input site | part A and the output site | part B in the signal conductor 9 and the position of the grounding site | part C in the grounding conductor 8 from one end surface. is there. 3 is a perspective view showing a configuration of a filter element 61. FIG. FIG. 6 is a plan view of the filter element 61 (101) as viewed from one end face for showing the positions of the input part A and the output part B in the signal conductor 9 and the position of the ground part C in the grounding conductor 8; is there. 3 is a perspective view showing a configuration of a filter element 71. FIG. In order to show the structure of the filter element 71 (91), it is a perspective view of the state which unwound the coil part 75 (95). 3 is a perspective view showing a configuration of a filter element 81. FIG. In order to show the structure of the filter element 81 (101), it is the perspective view of the state which unwinded the coil part 85 (105). 3 is a perspective view showing a configuration of a filter element 91. FIG. 2 is a perspective view showing a configuration of a filter element 101. FIG. 6 is an attenuation characteristic diagram showing a relationship between a frequency and an attenuation amount in a normal mode of filter elements according to Example 1 and Comparative Example 1. FIG. 6 is an attenuation characteristic diagram showing a relationship between a frequency and an attenuation amount for a common mode of filter elements according to Example 1 and Comparative Example 1. FIG.

Explanation of symbols

1, 21, 31, 41, 51, 61, 71, 81, 91, 101 Filter element 2, 2a, 2b Input terminal 3, 3a, 3b Output terminal 4 Grounding terminal 5, 25, 35, 45, 55, 65 , 75, 85, 95, 105 Coil portion 7a, 7b Strip insulator 8, 8a, 8b Grounding conductor 9, 9a, 9b Signaling conductor 10 Sheet-like conductor O Central axis

Claims (10)

Winding the pair of signal strip conductors and the ground strip conductor over the pair of signal strip conductors so that the ground strip conductor is outside the pair of signal strip conductors. By including a coil portion formed in a cylindrical shape as a whole,
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 conductor is wound around the coil portion in a floating state so as to face the pair of signal strip-like conductors. Winding the pair of signal strip conductors and the ground strip conductor over the pair of signal strip conductors so that the ground strip conductor is on the inside with the strip strip conductors overlapped. By including a coil portion formed in a cylindrical shape as a whole,
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 conductor is wound around the coil portion in a floating state so as to face the pair of signal strip-like conductors.   The filter element according to claim 1 or 2, wherein a pair of the sheet-like conductors are provided so as to face the pair of signal strip-like conductors. By winding the signal strip conductor and the ground strip conductor on the signal strip conductor so that the ground strip conductor is on the outside in a state where the strip strip conductor is overlapped via the strip insulator. As a coil part formed in a cylindrical shape,
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 conductor is wound around the coil portion in a floating state so as to face the signal strip-like conductor. By winding the signal strip conductor and the ground strip conductor over the signal strip conductor so that the ground strip conductor is on the inside in a state where the strip strip conductor is overlapped via the strip insulator. As a coil part formed in a cylindrical shape,
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 conductor is wound around the coil portion in a floating state so as to face the signal strip-like conductor.   The filter element according to any one of claims 1 to 5, wherein the sheet-like conductor is configured by separating one part of the grounding strip-like conductor from other parts of the grounding strip-like conductor. The grounding part is located on the opposite side of the input part across the center of the coil part,
The filter element according to claim 1, wherein the output part is located on the opposite side of the input part across the center of the coil portion. The grounding part is located on the opposite side of the input part across the center of the coil part,
The filter element according to claim 1, wherein the output part is located on the opposite side of the ground part with the center of the coil portion interposed therebetween.   The filter element according to any one of claims 1 to 8, wherein a magnetic body is disposed in a gap formed in a central portion of the coil portion. An input terminal is connected to the input part,
An output terminal is connected to the output site;
The filter element according to claim 1, wherein a grounding terminal is connected to the grounding part.

Images