Electrical filter element and electrical assembly
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026053000_13082026_PF_FP_ABST
Abstract
Description
[0001] P2025, 0094 WO N February 5, 2026
[0002] 1
[0003] Description
[0004] Electrical filter element and electrical assembly
[0005] In the following, an electrical filter element and electrical assembly are specified.
[0006] To ensure suitable noise filtering of AC (alternating current) signals of a power electronic device, for instance in electric vehicles, at higher frequencies usually a multistage filter unit, i . e . , a filter unit of the order greater than 1 with more than one filter stages, is used. Each filter stage for filtering high frequency electromagnetic interference (EMI ) noise typically comprises at least one inductance and two so-called Cy capacitances in the case of an isolated system with three levels, i . e . with a "plus" potential, a "minus" potential and a ground potential . Alternatively, a filter stage comprises at least one inductance and one capacitance in the case of a two-level system, i . e . a "plus" potential and a "minus" potential that may be equal to the ground potential . Such a multistage filter unit causes high costs due to the need of many components like inductive cores and capacitors on a printed circuit board (PCB) , and requires a certain space within a power electronic device . Furthermore, the performance of Cy capacitors in the high frequency region depends on parasitic inductors like the feed of the capacitors and the grounding situation of the PCB, for instance due to screws and the housing ground potential .
[0007] At least one obj ect of particular embodiments is to provide an electrical filter element . At least one further obj ect ofP2025, 0094 WO N February 5, 2026
[0008] 2
[0009] particular embodiments is to provide an electrical assembly comprising the electrical filter element .
[0010] These obj ects are achieved by sub ect-matters according to the independent claims . Advantageous embodiments and developments of the subj ect-matters are characterized in the dependent claims, and are also disclosed by the following description and the drawings .
[0011] According to at least one embodiment, an electrical filter element for filtering AC noise in at least one conductor line due to permittivity and permeability loss mechanisms is specified. In particular, the electrical filter element comprises a magneto-dielectric loss element . The magnetodielectric loss element comprises or is preferably made of a material having ferromagnetic and dielectric properties, in particular a magneto-dielectric loss material having a relative dielectric permittivity s with ^^ rix s' ' , wherein s' and s' ’ are the real and imaginary parts, respectively, and a relative magnetic permeability p with p=p,+ixp, ,, wherein p' and p' ' are the real and imaginary parts, respectively. In particular, the permittivity, preferably its loss component s' ’ , and the permeability, preferably its loss component p' ' , are large, so that the magneto-dielectric loss element can provide preferably high losses to AC components . In particular, the electrical filter element makes use of the conductive (resistive) component of s' ’ .
[0012] According to a further embodiment, the magneto-dielectric loss element comprises a first surface and a second surface opposite to the first surface . At least a part of the material of the magneto-dielectric loss element is situated between the first surface and the second surface, so that atP2025, 0094 WO N February 5, 2026
[0013] 3
[0014] least a part of the magneto-dielectric loss element is sandwiched between the first and second surfaces . Preferably, the first surface and the second surface face, at least partly or completely, in opposite directions .
[0015] According to a further embodiment, the electrical filter element comprises a first conductor element on the first surface and a second conductor element on the second surface . Each of the first conductor element and the second conductor element is preferably a continuous element that covers a continuous area . The first conductor element can partly cover the first surface . Alternatively, the first conductor element can completely cover the first surface . The second conductor element can partly cover the second surface . Alternatively, the second conductor element can completely cover the second surface . Accordingly, at least a part of the magnetodielectric loss element is sandwiched between the first and second conductor elements .
[0016] According to a further embodiment, the electrical filter element comprises an insulator element . The insulator element comprises or is preferably made of an electrically insulating material . The at least one insulator element is arranged between the first conductor element and the first surface or between the second conductor element and the second surface . The at least one insulator element can comprise an electrically insulating foil adhered to the magnetodielectric loss element or an electrically insulating coating or an electrically insulating ceramic material . Due to the at least one insulator element the first conductor element or the second conductor element is electrically insulated from the magneto-dielectric loss element . The insulator element can be, for instance, a thin, non-conductive insulatorP2025, 0094 WO N February 5, 2026
[0017] 4
[0018] material and can not only prevent electrical short circuits but can also provide a required creepage distance in high-voltage applications like applications exceeding 60 V.
[0019] Preferably, the insulator element can comprise or be made of one or more materials chosen from silicone, polyimide, polyethylene . Depending on the potential levels of the conductor elements and, thus, the potential or voltage difference between the conductor elements, as well as the conductivity of the magneto-dielectric loss element, a separate insulating element may not always be necessary as the insulating element can be integrated in the magnetodielectric loss element .
[0020] According to a further embodiment, an electrical assembly for reducing electromagnetic interference noise in a first electrical conductor line comprises the electrical filter element . In particular, the first electrical conductor line is connected to the first conductor element of the electrical filter element . Thus, the first conductor element is on a first electrical potential . Furthermore, the first conductor element and the second conductor element of the electrical filter element are at different electrical potentials . The second conductor element is therefore at a second electrical potential different from the first electrical potential . In other words, the first and second conductor elements are connected to external conductors with different electrical voltages, wherein one of the external conductors is the first conductor line and the other external conductor can be another conductor line or a housing part or another component providing a desired electrical potential . Consequently, there is a potential difference between the first conductor element and the second conductor element of the electrical filter element . Preferably, the second conductor element can beP2025, 0094 WO N February 5, 2026
[0021] 5
[0022] connected to an electrical conductor having an electrical potential different from a ground potential .
[0023] The features and embodiments described before and in the following equally apply to the electrical filter element and the electrical assembly.
[0024] As described above, the electrical filter element comprises at least two conductor elements, i . e . at least the first and second conductor elements, on the magneto-dielectric loss element . In the electrical assembly the at least two conductor elements are connected to external electrical conductors, one of which is provided by the first conductor line, that are at different electrical potentials (voltages) . As a consequence, the material of the magneto-dielectric loss element of the electrical filter element can simultaneously cause magnetic and dielectric losses for AC components at least in the first conductor line . As a result, the electrical filter element can reduce AC components of the applied voltage and current, preferably over a broad frequency range, at least in the first conductor line .
[0025] According to a further embodiment, the magneto-dielectric loss element comprises or is made of a magneto-dielectric loss material with a magnetic component and a dielectric component . The magnetic component can comprise a ferrite and / or magnetic particles . In particular, the magnetic component can be one or more chosen from ferrites, such as MnZn, NiZn and nanocrystalline, and metallic magnetic particles, such as Fe, Mn, Ni and Co . The dielectric component can comprise a ceramic material and / or a polymer material . In particular, the dielectric component can be one or more chosen from ceramic materials like BaTiO3and / or TiO2P2025, 0094 WO N February 5, 2026
[0026] 6
[0027] and polymer materials like silicone, polyimide or polyethylene . Ferrites can be provided in a solid form or as fine magnetic powder dispersed in a flexible polymer matrix, creating a flexible type .
[0028] According to a further embodiment, the first conductor element and / or the second conductor element comprises or is made of a metal, preferably comprising or being made of Cu. The first conductor element and / or the second conductor element can, for instance, be a metal layer . The metal layer can be a metal sheet adhered to the magneto-dielectric loss element or a metal coating deposited onto the material of the magneto-dielectric loss element .
[0029] According to a further embodiment, the electrical filter element is a solid element and can have a shape that can be rectangular, circular, elliptical, polygonal, flat-plated or a combination thereof . For instance, the first surface and the second surface can be outer surfaces of the magnetodielectric loss element that face in opposite directions and that are connected to each other by one or more plane or curved side surfaces . In this case, the magneto-dielectric loss element can have, for example, a block-like shape or a sheet-like shape .
[0030] Furthermore, the magneto-dielectric loss element can comprise at least one opening, also denoted as first opening, wherein the first surface can be an inner surface of the at least one opening and the second surface can be an outer surface of the magneto-dielectric loss element facing away from the at least one opening. The at least one opening can have a crosssection that is rectangular, circular, elliptical, polygonal or a combination thereof . The cross-section of the firstP2025, 0094 WO N February 5, 2026
[0031] 7
[0032] surface and the cross-section of the second surface, as seen in a direction into the at least one opening, can be the same or different . The first conductor element can be a layer or coating on the inner surface of the at least one opening. Alternatively, the first conductor element can completely fill the at least one opening. Furthermore, it can also be possible that the first conductor element is formed as a coil in the at least one opening. For example, the magnetodielectric loss element can be formed as a single core element, such as a cuboid core or a cylindrical core, with a through-opening, or as a two-part core element like a combination of two U-cores or a U-core and an I-core that surround an opening. Furthermore, the electrical filter element can be formed as a ceramic multilayer component . In the electrical assembly the first conductor line can be connected to the first conductor element without reaching through the at least one opening. Alternatively, the first electrical conductor line can reach through the at least one opening .
[0033] According to a further embodiment, the magneto-dielectric loss element is a flexible element . In particular, the electrical filter element can be formed as a multilayer foil . In this case, the electrical filter element can comprise one or more foils of magneto-dielectric loss material forming magneto-dielectric loss elements between conductor elements that are formed by metal foils or metal coatings . Each pair of conductor elements that are separated by a foil form a first conductor element and a second conductor element as described above . The magneto-dielectric loss element with the conductor elements can be rolled in a spiral shape in order to increase the overlapping area and enhance the loss .P2025, 0094 WO N February 5, 2026
[0034] 8
[0035] According to a further embodiment, the at least one insulator element can be in direct mechanical contact with the magnetodielectric loss element . Consequently, the at least one insulator element can be in direct mechanical contact with the first surface or with the second surface of the magnetodielectric loss element . Furthermore, in case the at least one insulator element is on the first surface, the first conductor element can be in direct mechanical contact with the at least one insulator element . In case the at least one insulator element is on the second surface, the second conductor element can be in direct mechanical contact with the at least one insulator element . Due to the at least one insulator element, an electrical connection between the first conductor element and the second conductor element can be prevented even in case the magneto-dielectric loss element is electrically conducting.
[0036] According to a further embodiment, neither of the first conductor element and the second conductor element is in direct mechanical contact with the magneto-dielectric loss element . The at least one insulator element can comprise a first insulator element and a second insulator element, so that the electrical filter element can comprise a first insulator element and a second insulator element . The first insulator element is preferably arranged between the first conductor element and the first surface and the second insulator element is arranged between the second conductor element and the second surface . Features and embodiments described in connection with the at least one insulator element can apply to the first insulator element and / or the second insulator element, wherein the first and second insulator element can be similar or different .P2025, 0094 WO N February 5, 2026
[0037] 9
[0038] According to a further embodiment, the magneto-dielectric loss element comprises a third conductor element on the first surface or on a third surface different from the first surface and from the second surface . Features and embodiments described in connection with the first surface can also apply to the third surface . Furthermore, features and embodiments described in connection with the first conductor element can also apply to the third conductor element . For example, the magneto-dielectric loss element comprises a second opening, wherein an inner surface of the second opening is the third surface and the third conductor element is on the third surface .
[0039] According to a further embodiment, a second electrical conductor line can be connected to the third conductor element of the electrical filter element . In this case, it can be possible to use the electrical filter element in the electrical assembly as a common-mode filter element or a differential-mode filter element .
[0040] The electrical filter element described herein allows providing efficient noise filtering using the magnetodielectric loss element with the conductor elements instead of an inductance in combination with additional capacitors . The electrical filter element can be used, for instance, instead of one or more conventional filter stages, like LC filter stages, in a multistage filter . Alternatively, the electrical filter element can be used to replace a usually used multistage filter .
[0041] Two or more conductor elements as described above are arranged on one or more inner and / or outer surfaces of the magneto-dielectric loss element in order to generate both aP2025, 0094 WO N February 5, 2026
[0042] 10
[0043] magnetic field and an electric field within it . By stacking the conductor elements in parallel and sandwiching the material of the magneto-dielectric loss element between them, an electric field is produced between the conductor elements . The conductor elements themselves may be line-shaped, planar, spiral, or may have multilayer structures . By varying the distance between conductor elements and by adjusting each conductor element' s area and / or length, one can control the amount of loss and the frequency band in which the loss takes place . Furthermore, by adjusting the material and the dimensions like the thickness, area and length as well as the shape of the magneto-dielectric loss element, one can also tune both the magnitude of loss and the frequency range over which the loss occurs . Moreover, as described above, each of the two or more conductor elements is connected to a different electrical potential . The higher the electrical potential and, in particular, the greater the potential difference, the greater is the loss generated in the magnetodielectric loss element . Thus, the level of electrical potential applied to the conductor elements can also be used to control the amount of loss . Moreover, by selecting the material, thickness and area of the at least one insulator element, one can control both the magnitude of the loss and the frequency range in which the loss occurs .
[0044] The magneto-dielectric loss element of the electrical filter element described herein can be understood as a single-core element that can ensure the advantage of both inductive-like and capacitive-like filtering with only a single component, since the noise reduction is achieved by using both magnetically and dielectrically losses . In other words, the dielectric permittivity properties of the magneto-dielectric loss element can be used to reduce high frequency EMI noise,P2025, 0094 WO N February 5, 2026
[0045] 11
[0046] wherein it can be possible to replace expensive materials like NiZn by cheaper materials like MnZn, while maintaining the same benefit of filtering efficiency at higher frequencies . In particular, the electrical filter element is not influenced by parasitic inductances in high frequency ranges of usual filter solutions with capacitors . Compared to usual filter designs, the filter module formed by the electrical filter element can be constructed with a smaller volume and lower costs and can be implemented with many geometrical variations of the magneto-dielectric loss element .
[0047] Further advantages, advantageous embodiments and further developments are revealed by the embodiments described below in connection with the figures .
[0048] Figure 1 shows a schematic illustration of an electrical filter element according to an embodiment,
[0049] Figure 2 shows a schematic illustration of an electrical assembly according to a further embodiment,
[0050] Figure 3 shows a simulation of filter effects of an electrical filter element and comparative filters, Figures 4 and 5 show schematic illustrations of an electrical filter element according to further embodiments, Figures 6 to 11 show schematic illustrations of an electrical filter element according to further embodiments, Figures 12 and 13 show a schematic illustrations of an electrical assembly according to further embodiments, Figures 14A to 19 show schematic illustrations of an electrical filter element according to further embodiments ,
[0051] Figure 20 shows a schematic illustration of an electrical assembly according to a further embodiment .P2025, 0094 WO N February 5, 2026
[0052] - 12 -
[0053] In the embodiments and figures, identical, similar or identically acting elements are provided in each case with the same reference numerals . The elements illustrated and their size ratios to one another should not be regarded as being to scale, but rather individual elements, such as for example layers, components, devices and regions, may have been made exaggeratedly large to illustrate them better and / or to aid comprehension.
[0054] The figures described in the following are directed to exemplary embodiments . However, the following description is not to be construed as limiting the disclosure . Thus, features in the following embodiments which are not recited in an independent claim are to be understood as optional and may be provided on an as-needed basis . In particular, the features and embodiments described in connection with the figures can also be combined with one another according to further embodiments, even if not all such combinations are explicitly described. Furthermore, the embodiments described in connection with the figures can alternatively or additionally have further features according to the description in the general part .
[0055] Figure 1 shows a partial sectional view of an electrical filter element 100 according to an embodiment . The electrical filter element 100 is configured for filtering, i . e . reducing, AC noise, i . e . undesired AC components that can be caused, for instance, by EMI, in at least one conductor line due to permittivity and permeability loss mechanisms .
[0056] The electrical filter element 100 comprises a magnetodielectric loss element 10 that comprises or is preferablyP2025, 0094 WO N February 5, 2026
[0057] 13
[0058] made of a magneto-dielectric loss material having ferromagnetic and dielectric properties and has a relative dielectric permittivity s and a relative magnetic permeability p as specified above in the general part .
[0059] Particularly preferably, the permittivity, in particular the loss component s' ’ , and the permeability, in particular the loss component p' ' , are large, so that the magneto-dielectric loss element 10 can provide high losses to AC components .
[0060] The magneto-dielectric loss element 10 comprises or is made of a magneto-dielectric loss material with a magnetic component and a dielectric component . The magnetic component can comprise, for example, a ferrite and / or magnetic particles . In particular, the magnetic component can be one or more chosen from ferrites, such as MnZn, NiZn and nanocrystalline, and metallic magnetic particles, such as Fe, Mn, Ni and Co . The dielectric component can comprise a ceramic material and / or a polymer material . In particular, the dielectric component can be one or more chosen from ceramic materials like BaTiO3and / or TiO2and polymer materials like silicone, polyimide or polyethylene . Ferrites can be provided in a solid form or as fine magnetic powder dispersed in a flexible polymer matrix, creating a flexible type as described further below.
[0061] The magneto-dielectric loss element 10 comprises a first surface 11 and a second surface 12 opposite to the first surface 11. At least a part of the material of the magnetodielectric loss element 10 is situated and, thus, sandwiched between the first surface 11 and the second surface 12.
[0062] Preferably, the first surface 11 and the second surface 12 can face in opposite directions as indicated in Figure 1.P2025, 0094 WO N February 5, 2026
[0063] 14
[0064] Furthermore, the electrical filter element 100 comprises a first conductor element 21 on the first surface 11 and a second conductor element 22 on the second surface 12. Each of the first conductor element 21 and the second conductor element 22 is preferably a continuous element that covers a continuous area on the respective surface . In other words, preferably neither of the first and second conductor elements 21, 22 are structured into several separate parts . The first conductor element 21 can partly or completely cover the first surface 11. The second conductor element 22 can partly or completely cover the second surface 12.
[0065] Each of the first conductor element 21 and the second conductor element 22 comprises or is made of a metal, preferably comprising or being made of Cu. For example, the first conductor element 21 and / or the second conductor element 22 can be a metal layer, for example a metal sheet adhered to the magneto-dielectric loss element 10, or a metal coating deposited onto the material of the magneto-dielectric loss element 10. It can also be possible that at least one of the first and second conductor elements 21, 22 is a metal sheet that is mechanically fastened to the magneto-dielectric loss element 10.
[0066] Furthermore, the electrical filter element 100 comprises at least one insulator element 31. The at least one insulator element 31 can comprise an electrically insulating foil adhered or mechanically fastened to the magneto-dielectric loss element 10 or an electrically insulating coating or an electrically insulating ceramic material disposed on the magneto-dielectric loss element 10. The at least one insulator element 31 comprises or is preferably made of an electrically insulating material such as an electricallyP2025, 0094 WO N February 5, 2026
[0067] 15
[0068] insulating ceramic material like barium titanate or aluminum oxide or a polymer material like silicone, polyimide or polyethylene . The insulator element 31 can be, for instance, a thin, non-conductive isolator material and can not only prevent electrical short circuits but can also provide a required creepage distance in high-voltage applications, such as applications exceeding 60 V.
[0069] In the embodiment shown in Figure 1, the at least one insulator element 31 is arranged between the first conductor element 21 and the first surface 11. Due to the at least one insulator element 31 the first conductor element 21 is electrically insulated from the magneto-dielectric loss element 10.
[0070] Preferably, the at least one insulator element 31 is in direct mechanical contact with the magneto-dielectric loss element 10. Consequently, in the embodiment shown in Figure 1 the at least one insulator element 31 is preferably in direct mechanical contact with the first surface 11 of the magnetodielectric loss element 10. Furthermore, the first conductor element 21 can be in direct mechanical contact with the at least one insulator element 31. The second conductor element 22 can be in direct mechanical contact with the second surface 12 of the magneto-dielectric loss element 10. Due to the at least one insulator element 31, an electrical connection between the fist conductor element 21 and the second conductor element 22 can be prevented even in case the magneto-dielectric loss element 10 is electrically conducting .
[0071] Figure 2 shows an embodiment for an electrical assembly 1000 for reducing electromagnetic interference noise on a firstP2025, 0094 WO N February 5, 2026
[0072] 16
[0073] electrical conductor line 111. The electrical assembly 1000 comprises the electrical filter element 100 of Figure 1.
[0074] The first electrical conductor line 111 is connected to the first conductor element 21 of the electrical filter element 100. Thus, the first conductor element 21 is on a first electrical potential provided by the first conductor line 111. Furthermore, as indicated by the dotted connection 110, the second conductor element 22 is connected to a second electrical potential different from the first electrical potential . The second conductor element 22 can for instance be connected to an electrical conductor having an electrical potential different from a ground potential . Consequently, the first conductor element 21 and the second conductor element 22 of the electrical filter element 100 are at different electrical potentials . In other words, the first and second conductor elements 21, 22 are connected to the external conductors, one of which is the first conductor line 111, with different electrical voltages . Consequently, there is a potential difference between the first conductor element 21 and the second conductor element 22 of the electrical filter element 100.
[0075] The electrical filter element 100 allows efficient noise filtering using the magneto-dielectric loss element 10 in combination with the conductor elements 21, 22 instead of a conventional filter with an inductance in combination with additionally capacitors . Figure 3 shows an exemplary simulation of a comparison of the filtering properties in terms of inserted loss depending of the frequency f of comparative filters to the electrical filter element described herein. In particular, a first comparative filter is a single inductance as indicated by circuit CA. TheP2025, 0094 WO N February 5, 2026
[0076] 17
[0077] corresponding frequency dependent inserted loss is represented by graph A. A second comparative filter is an LC filter as indicated by circuit CB . The corresponding frequency dependent inserted loss is represented by graph B . The electrical filter element as described herein is indicated by circuit CO . The corresponding frequency dependent inserted loss is represented by graph graph C .
[0078] As can be easily seen, the electrical filter element described herein, which is a single component using both magnetically and dielectrically loss mechanisms, can achieve the filter performance of a conventional LC filter having multiple components .
[0079] In particular, with the electrical filter element as described in connection with the figures it is possible to filter, i . e . reduce, EMI noise on at least one or more conductor lines, for instance supply lines of a power electronic device, by using the magnetic and dielectric properties of the material of the magneto-dielectric loss element . In particular, both loss mechanisms, i . e . loss caused by the magnetic properties and loss caused by the dielectric properties of a magnetic material, are preferably used for EMI noise reduction. Depending on the conductor line number, also the differential noise and / or common mode noise can be filtered. In particular, high frequency noise, i . e . noise at frequencies up to a few 100 MHz conducted on the line can be decreased since the EMI noise can be reduced due to the magnetic property of the magneto-dielectric loss element and due to the dielectric / dissipative property of the magneto-dielectric loss element .P2025, 0094 WO N February 5, 2026
[0080] 18
[0081] In the following, embodiments and further features of the electrical filter element 100 and the electrical assembly 1000 are described, wherein redundant description is omitted, so that merely differences to previous embodiments are explained. Elements and their functions that are not explained in connection with the following figures can be embodied as described in previous embodiments .
[0082] Figures 4 and 5 show modifications of the electrical filter element 100 described in connection with Figures 1 and 2. The electrical filter element 100 according to the embodiments of Figures 4 and 5 can be likewise a part of the electrical assembly 1000 shown in Figure 2.
[0083] In the embodiment of Figure 4, the at least one insulator element 31 is arranged between the second conductor element 22 and the second surface 12 of the magneto-dielectric loss element 10. The description of the insulator element 31 of the electrical filter element 100 shown in Figures 1 and 2 similarly applies to the embodiment of Figure 4. In particular, the at least one insulator element 31 is preferably in direct mechanical contact with the second surface 12 of the magneto-dielectric loss element 10 and the second conductor element 22 is preferably in direct mechanical contact with the at least one insulator element 31. The first conductor element 21 can be in direct mechanical contact with the first surface 11 of the magnetodielectric loss element 10.
[0084] Figure 5 shows an embodiment of the electrical filter element 100 in which neither of the first and second conductor elements 21, 22 is in direct mechanical contact with the magneto-dielectric loss element 10. Compared to the previousP2025, 0094 WO N February 5, 2026
[0085] 19
[0086] embodiments, the electrical filter element 100 according to Figure 5 comprises a first insulator element 31 and a second insulator element 32. The first insulator element 31 is arranged between the first conductor element 21 and the first surface 11 and a second insulator element 32 is arranged between the second conductor element 22 and the second surface 12. Features and embodiments of the at least one insulator element 31 as described before in connection with the previous embodiments can apply to the first insulator element 31 and / or the second insulator element 32, wherein the first and second insulator elements 31, 32 can be similar or different to each other .
[0087] The electrical filter element 100 described herein can be a solid element and can have a shape that can be rectangular, circular, elliptical, polygonal, flat-plated or a combination thereof . For instance, the first surface 11 and the second surface 12 can be outer surfaces of the magneto-dielectric loss element 10 that face in opposite directions as indicated in Figures 1 to 4 . The first and second surfaces 11, 12 can be connected to each other by side surfaces of the magnetodielectric loss element 10. In this case, the magnetodielectric loss element 10 can have, for example, a blocklike shape or a sheet-like shape . Furthermore, the magnetodielectric loss element 10 can comprise at least one opening, wherein the first surface 11 can be an inner surface of the at least one opening and the second surface 12 can be an outer surface of the magneto-dielectric loss element 10 facing away from the at least one opening. Moreover, the magneto-dielectric loss element 10 can be a flexible element . In particular, the electrical filter element 100 can be formed as a multilayer foil .P2025, 0094 WO N February 5, 2026
[0088] 20
[0089] By varying the distance between conductor elements 21, 22 and by adjusting each conductor element' s area and / or length, one can control the amount of loss and the frequency band in which the loss takes place . Furthermore, by adjusting the material and dimensions like the thickness, area and length as well as the shape of the magneto-dielectric loss element 10, one can also tune both the magnitude of loss and the frequency range over which the loss occurs . Moreover, as described above, each of the two or more conductor elements 21, 22 is connected to a different electrical potential in the electrical assembly 1000. The higher the electrical potential and, in particular, the greater the potential difference, the greater is the loss generated in the magnetodielectric loss element 10. Thus, the level of electrical potential applied to the conductor elements 21, 22 can also be used to control the amount of loss . Moreover, by selecting the material, thickness and area of the at least one insulator element 31, 32, one can control both the magnitude of the loss and the frequency range in which the loss occurs .
[0090] Preferred embodiments of the electrical filter element 100 and the electrical assembly 1000 are described in connection with the following figures . However, the following description is not to be construed as limiting the disclosure . The at least one insulator element 31, 32 is not shown in the following figures . However, although not explicitly shown in the figures, in the embodiments described in the following one or more insulator elements can be arranged between the first conductor element 21 and the first surface 11 of the magneto-dielectric loss element 10 and / or between the second conductor element 21 and the second surface 12 of the magneto-dielectric loss element 10.P2025, 0094 WO N February 5, 2026
[0091] 21
[0092] Figure 6 shows in a sectional view an embodiment of the electrical filter element 100 which has a magneto-dielectric loss element 10 that has a cuboid shape formed by a combination of a U-core shaped first part 18 and an I-core shaped second part 19. Alternatively, both the first and second parts 18, 19 could for example be U-core shaped. The magneto-dielectric loss element 10 has an opening 41, also denoted below as first opening, which is a through-opening reaching through the magneto-dielectric loss element 10 in a direction perpendicular to the drawing plane . Due to the shape of the parts 18, 19, the opening 41 as well as the outer circumference of the magneto-dielectric loss element 10 both have a rectangular cross-section when seen along the direction into the opening 41, i . e . when seen in a direction perpendicular to the drawing plane . The first surface 11 of the magneto-dielectric loss element 10 is, in the shown orientation, the bottom inner surface of the opening 41, whereas the second surface 12 is the bottom outer surface of the U-core shaped first part 18 facing away from the first surface 11. Both the bottom inner surface and the bottom outer surface are completely covered by the first conductor element 21 and the second conductor element 22, respectively, which both can be, for instance, a metal sheet adhered to the magneto-dielectric loss element 10.
[0093] Figure 7 shows a modification of the embodiment of Figure 6, wherein both the bottom inner surface and the bottom outer surface, i . e . the first and second surfaces 11, 12, are partly covered by the first conductor element 21 and the second conductor element 22, respectively. As in the previous embodiment the first and second conductor elements 21, 22 can each be a metal sheet adhered to the magneto-dielectric loss element, respectively. Alternatively, the first conductorP2025, 0094 WO N February 5, 2026
[0094] 22
[0095] element 21 can have a lead-frame like structure as shown in Figure 8, which has a middle portion 210 placed inside the opening 41 and two end portions 211, 212 that protrude from the magneto-dielectric loss element 10 and that comprise for example mounting holes for connecting at least one conductor line to the first conductor element 21 of the electrical filter element 100.
[0096] Figure 9 shows another modification of the embodiment of Figure 6, wherein the first surface 11 is the complete inner surface of the opening 41 and is completely covered by the first conductor element 21 which can be a metal sheet, while the second surface 12 is the complete outer surface, apart from a front surface and back surface of the magnetodielectric loss element 10 parallel to the drawing plane, and is completely covered by the second conductor element 22 which can also be a metal sheet . It can also be possible that the first conductor element 21 is for example a metal bulk that completely fills the opening 41.
[0097] Figures 10 and 11 show sectional views of further modifications of the embodiment of Figure 6 having a magnetodielectric loss element 10 that is formed by single core-like part with the shape of a cylinder with an opening 41. The first surface 11 is the inner surface of the opening 41, while the second surface 12 is the outer lateral surface of the magneto-dielectric loss element 10. As shown in Figure 10, both the first surface 11 and the second surface 12 can be partly covered by the first and second conductor elements 21 , 22, respectively, which both can be a metal sheet .
[0098] Alternatively, at least one of the first and second surfaces 11, 12 can be completely covered by the respective conductor element 21, 22. Furthermore, as shown in Figure 11, the firstP2025, 0094 WO N February 5, 2026
[0099] 23
[0100] conductor element 21 can be a metal bulk completely filling the opening 41 .
[0101] Figures 12 and 13 each show in sectional views along a sectional plane perpendicular to the sectionals views of Figures 6, 7 and 9 to 11 an electrical assembly 1000 with an electrical filter element 100, wherein the electrical filter element 100 can have, for instance, one of the shapes described in connection with Figures 6 to 10. By way of example only, the first conductor element 21 can protrude from the front and back surface (s) that connect the first surface 11 to the second surface 12.
[0102] As explained in connection with Figure 2, a first conductor line 111 having a first electrical potential is connected to the first conductor element 21, while the second conductor element 22 is connected to a second electrical potential different from the first electrical potential, as indicated by the dotted connection 110. The first conductor line 111 can be arranged outside the opening 41 as indicated in Figure 12 or can reach through the opening 41 and, thus, through the electrical filter element 100 as indicated in Figure 13. In case the first conductor line 111 reaches through the electrical filter element 100, the filtering effect of the electrical filter element 100 can be increased.
[0103] Figure 14A and 14B show in a three-dimensional view and an exploded partial three-dimensional view an embodiment of the electrical filter element 100 that is embodied as a ceramic multilayer component . The electrical filter element 100 comprises a plurality of ceramic layers that are formed as magneto-dielectric loss elements 10 with conductor elements 21, 22 in-between. The conductor elements 21, 22 form firstP2025, 0094 WO N February 5, 2026
[0104] 24
[0105] conductor elements 21 and second conductor elements 22 that are stacked alternating on top of each other, so that each of the magneto-dielectric loss elements 10 is arranged between a first conductor element 21 and a second conductor element 22. In other words, each magneto-dielectric loss element 10 has a first surface 11 with a first conductor element 21 and a second surface 12 with a second conductor element 22 thereon. Consequently, the electrical filter element 100 preferably comprises a stack with sub-elements on top of each other, each sub-element comprising a first conductor element 21, a magneto-dielectric loss element 10 and a second conductor element 22. Adj acent sub-elements can share a first or second conductor element 21, 22. In addition, ceramic layers forming insulating elements can be arranged between conductor elements 21, 22 and magneto-dielectric loss elements 10.
[0106] In the embodiment of Figures 14A and 14B, by way of example only, all first conductor elements 21 are electrically contacted to first external contacts 51 on end surfaces of the electrical filter element 100, while all second conductor elements 22 are electrically contacted to second external contacts 52 on side surfaces of the electrical filter element 100 .
[0107] Figure 15 shows in a sectional view a further embodiment of the electrical filter element 100 being formed as a ceramic multilayer component . In contrast to the previous embodiment the electrical filter element 100 comprises a magnetodielectric loss element 10 made from a plurality of ceramic layers with a coil-formed first conductor element 21 reaching through the magneto-dielectric loss element 10. Thus, the magneto-dielectric loss element 10 comprises an opening 41 spiraling through the magneto-dielectric loss element 10 andP2025, 0094 WO N February 5, 2026
[0108] 25
[0109] being filled with the first conductor element 21. External contacts 51 on end surfaces are provided for electrically contacting the first conductor element 21. A second conductor element 22 is arranged on the outer surface forming a second surface 12. In the shown embodiment a second conductor element 22 is formed at least on an upper surface and a lower surface, each of which form the second surface 12.
[0110] Alternatively, the second surface 12 can comprise all outer surfaces except the end surfaces and the second conductor element 22 can surround the magneto-dielectric loss element 10 .
[0111] Figures 16A and 16B show in a three-dimensional view and a three-dimensional exploded view a further embodiment of the electrical filter element 100 having a cylindrical magnetodielectric loss element 10 with an opening 41 and the second conductor element 22 on the outer lateral surface being the second surface 12 as described for instance in connection with Figures 10 and 11. Similarly to the embodiment of Figure 15, the first conductor element 21, which is a wire in this embodiment, is formed as a coil in the opening 41. The first conductor element 21 is wound on a winding support 61 that can be made, for instance, of a plastic material . The first conductor element 21 is electrically connected to external contacts 51 formed from leadframe parts . The second conductor element 22 can also be electrically connected to an external contact (not shown) . All components are mounted on a support element 62 that can also be made of a plastic material .
[0112] In Figure 17 a further embodiment of the electrical filter element 100 shown that is a flexible filter element . In particular, the electrical filter element 100 can be formed as a multilayer foil comprising at least a layer formed by aP2025, 0094 WO N February 5, 2026
[0113] 26
[0114] first conductor element 21, a layer formed by a magnetodielectric loss element 10, and a layer formed by a second conductor element 22 as indicated in Figure 17. However, similarly to the ceramic multilayer element shown in Figures 14A and 14B, the electrical filter element 100 of Figure 17 can comprise a plurality of layers formed by magnetodielectric loss elements 10 with first and second conductor elements 21, 22 arranged in-between and stacked alternating on top of each other . In particular, the magneto-dielectric loss element 10 can comprise one or more foils of magnetodielectric loss material forming the magneto-dielectric loss elements 10 between the conductor elements 21, 22 that are formed by metal foils or metal coatings . As explained in connection with Figures 14A and 14B, each pair of a first and a second conductor element 21, 22 with a magneto-dielectric loss element foil in-between forms a sub-element . The multilayer foil can be rolled in a spiral shape in order to achieve a compact form and to increase the overlapping area and enhance the loss .
[0115] Figures 18 and 19 show further embodiments of the electrical filter element 100, which have, in addition, a third conductor element 23 either on the first surface 11 or on a third surface 13 different from the first and second surfaces 11, 12. Figure 20 shows an electrical assembly 1000 with the electrical filter element 100 of Figure 19. By way of example only, in said embodiments the first and third conductor elements 21, 23 are formed similarly. However, it is also possible that the first and third conductor elements 21, 23 are embodied differently to each other .
[0116] In the embodiment shown in Figure 18, both the first conductor element 21 and the third conductor element 23 areP2025, 0094 WO N February 5, 2026
[0117] 27
[0118] arranged on a part of the first surface 11 that is the inner surface of the opening 41 as described, for instance, in connection with Figures 6 to 10.
[0119] In contrast, the magneto-dielectric loss element 10 of the electrical filter element 100 of Figure 19 comprises a first opening 41 that is filled with the first conductor element 21 as, for instance, explained in connection with Figure 11, so that the first surface that is the inner surface of the first opening 41 is completely covered by the first conductor element 21. Furthermore, the magneto-dielectric loss element 10 comprises a second opening 42, wherein an inner surface of the second opening 42 is the third surface and the third conductor element is on the third surface . In the shown embodiment, the third conductor element 23, similarly to the first conductor element 21 in the first opening 41, completely fills the second opening 42.
[0120] As shown in Figure 20, in the electrical assembly 1000 a first conductor line 111 having a first electrical potential is connected to the first conductor element 21, while the second conductor element 22 is connected to a second electrical potential as described in connection with Figures 12 and 13. Furthermore, a second conductor line 112 can be connected to the third conductor element 23 of the electrical filter element 100 as described above . Depending on the connection of the first and second conductor lines 111, 112, i . e . in parallel or anti-parallel directions, it can be possible to use the electrical filter element 100 as commonmode or differential-mode filter element .
[0121] The invention is not restricted by the description on the basis of the exemplary embodiments . Rather, the inventionP2025, 0094 WO N February 5, 2026
[0122] - 28 -
[0123] encompasses any new feature and also any combination of features, which in particular comprises any combination of features in the patent claims, even if this feature or this combination itself is not explicitly specified in the patent claims or exemplary embodiments .P2025, 0094 WO N February 5, 2026
[0124] - 29 -
[0125] Reference numerals
[0126] 10 magneto-dielectric loss element 11 first surface
[0127] 12 second surface
[0128] 18 part
[0129] 19 part
[0130] 21 first conductor element
[0131] 22 second conductor element
[0132] 23 third conductor element
[0133] 31 insulator element
[0134] 32 insulator element
[0135] 41 opening
[0136] 42 opening
[0137] 51 external contact
[0138] 52 external contact
[0139] 61 winding support
[0140] 62 support element
[0141] 100 electrical filter element
[0142] 110 connection
[0143] 111 conductor line
[0144] 112 conductor line
[0145] 210 middle portion
[0146] 211 end portion
[0147] 212 end portion
[0148] 1000 electrical assembly
Claims
1. P2025 , 0094 WO N February 5 , 2026- 30 -Patent claims1 . Electrical filter element ( 100 ) for filtering AC noise in at least one conductor line ( 111 ) due to permittivity and permeability loss mechanisms , the electrical filter element ( 100 ) comprising- a magneto-dielectric loss element ( 10 ) comprising a first surface ( 11 ) and a second surface ( 12 ) opposite to the first surface ( 11 ) ,- a first conductor element ( 21 ) on the first surface ( 11 ) , - a second conductor element ( 22 ) on the second surface ( 12 ) , and- at least one insulator element ( 31 , 32 ) between the first conductor element ( 21 ) and the first surface ( 11 ) and / or between the second conductor element ( 22 ) and the second surface ( 12 ) .2 . Electrical filter element ( 100 ) according to claim 1 , wherein the at least one insulator element ( 31 , 32 ) is in direct mechanical contact with the magneto-dielectric loss element ( 10 ) .3 . Electrical filter element ( 100 ) according to claim 1 or 2 , wherein neither of the first and second conductor element ( 21 , 22 ) is in direct mechanical contact with the magneto-dielectric loss element ( 10 ) .4 . Electrical filter element ( 100 ) according to any one of the preceding claims , wherein the first conductor element ( 21 ) partly covers the first surface ( 11 ) and / or the second conductor element ( 22 ) partly covers the second surface ( 12 ) .P2025, 0094 WO N February 5, 2026315. Electrical filter element ( 100) according to any one of the claims 1 to 3, wherein the first conductor element (21 ) completely covers the first surface ( 11 ) and / or the second conductor element (22 ) completely covers the second surface ( 12 ) .
6. Electrical filter element ( 100) according to any one of the preceding claims, wherein the magneto-dielectric loss element ( 10) comprises a magnetic component and a dielectric component, wherein the magnetic component comprises a ferrite and / or metallic magnetic particles and the dielectric component comprises a ceramic material and / or a polymer material .
7. Electrical filter element ( 100) according to any one of the preceding claims, wherein the first conductor element (21 ) and / or the second conductor element (22 ) comprises a metal layer .
8. Electrical filter element ( 100) according to claim 7, wherein the metal layer is a metal sheet adhered to the magneto-dielectric loss element ( 10) or a metal coating.
9. Electrical filter element ( 100) according to any one of the preceding claims, wherein the at least one insulator element (31, 32 ) comprises an electrically insulating foil adhered to the magneto-dielectric loss element ( 10) or an electrically insulating coating or an electrically insulating ceramic material .
10. Electrical filter element ( 100) according to any one of the preceding claims, wherein the magneto-dielectric loss element ( 10) comprises a first opening (41 ) ,P2025 , 0094 WO N February 5 , 202632wherein the first surface ( 11 ) is an inner surface of the first opening ( 41 ) and the second surface ( 12 ) is an outer surface of the magneto-dielectric loss element ( 10 ) facing away from the first opening ( 41 ) .11 . Electrical filter element ( 100 ) according to claim 10 , wherein the first conductor element ( 21 ) completely fills the first opening ( 41 ) .12 . Electrical filter element ( 100 ) according to claim 10 , wherein the first conductor element ( 21 ) is formed as a coil in the first opening ( 41 ) .13 . Electrical filter element ( 100 ) according to any one of the preceding claims , wherein the magneto-dielectric loss element ( 10 ) comprises a third conductor element ( 23 ) on the first surface ( 11 ) or on a third surface di f ferent from the first surface ( 11 ) and the second surface ( 12 ) .14 . Electrical filter element ( 100 ) according to claim 13 , wherein the magneto-dielectric loss element ( 10 ) comprises a second opening ( 42 ) , wherein an inner surface of the second opening ( 42 ) is third surface and the third conductor element ( 23 ) is on the third surface .15 . Electrical assembly ( 1000 ) for reducing electromagnetic interference noise at least on a first electrical conductor line ( 111 ) , the electrical assembly ( 1000 ) comprising an electrical filter element ( 100 ) according to any one of the preceding claims , whereinP2025, 0094 WO N February 5, 202633- the first electrical conductor line ( 111 ) is connected to the first conductor element (21 ) of the electrical filter element ( 100) ,- the first and second conductor elements (21, 22 ) are at different electrical potentials .
16. Electrical assembly ( 1000) according to claim 15, wherein the second conductor element (22 ) of the electrical filter element ( 100) is connected to an electrical conductor having an electrical potential different from a ground potential .
17. Electrical assembly ( 1000) according to claim 15 or 16 and according to claim 10, wherein the first electrical conductor line ( 111 ) reaches through the first opening (41 ) .
18. Electrical assembly ( 1000) according to any one of claims 15 to 17 and according to claim 13 or 14, wherein a second electrical conductor line ( 112 ) is connected to the third conductor element (23) of the electrical filter element ( 100) .