A common mode filter includes a coil part in which a plurality of insulating layers having coils formed on one surfaces thereof and containing fillers are stacked; a first cover part disposed beneath the coil part; and a second cover part disposed on the coil part, wherein surface reforming layers improving close adhesion between the insulating layers are formed on at least one surfaces of the insulating layers.

A radiofrequency filter utilizing a common mode choke both as a traditional common mode choke as well as the inductance in a low pass filter. Filter topology as well as component selection is optimized for wide band operation. Common mode chokes allow differential currents to pass with little attenuation while common mode currents are effectively presented with an inductance in the common current path. This inductance is used in a low pass filter configuration to present an even higher attenuation to common mode currents. The use of multiple chokes and/or differing core materials contributes to wider band operation without pronounced resonances. The capacitance used in the low pass filter is connected in a way as to reduce its effect on the data signals while still being effective in filtering.

An electrical filter (10) is suitable for having a greater effectiveness for reducing the common mode current that an electrical device (30) can produce in the direction of a voltage source (20) which is used to supply this device. Such a filter can be useful for meeting the electromagnetic compatibility requirements set by the BMW Group Standard GS 95002-2 Electromagnetic Compatibility (EMC)requirements and tests on components up to 60 V nominal voltage.

Disclosed herein is a common mode filter that includes a winding core part and first and second wires wound in a same direction around the winding core part. The first and second wires constitute a first winding block on one endmost side in an axial direction of the winding core part, a second winding block on other endmost side in the axial direction of the winding core part, and a third winding block positioned between the first and second winding blocks. The second winding block is a winding block at an odd-numbered position counted from the first winding block. The first and second wires cross each other in an area between the first and third winding blocks and in an area between the second and third winding blocks.

Disclosed herein is a differential mode filter that includes first and second terminal electrodes provided on a first flange part of a core, and first and second wires wound around a winding core part of the core in an opposite direction to each other and connected respectively to the first and second terminal electrodes. The first and second wires cross each other on the winding core part to form a plurality of crossing portions that include first, second, and third crossing portions that are first, second, and third occurrences counting from the one end of the first and second wires, respectively. A first crossing angle between the first and second wires at the first crossing portion is larger than at least one of second and third crossing angles between the first and second wires at the second and third portions, respectively.

According to one embodiment, there is provided a multilayer substrate including a signal layer. The signal layer includes a first line and a second line which form a differential pair. The first line electrically connects a first node and a second node in the signal layer. The second line electrically connects a third node and a fourth node in the signal layer. The interval between the first line and the second line is approximately constant from the first node to the second node. A physical length from the third node to the fourth node in the second line is shorter than a physical length from the first node to the second node in the first line. A width of the second line is thicker than a width of the first line.

A common mode filter includes a substrate; an insulating layer disposed on the substrate and including coil patterns, the insulating layer having a cavity disposed in a central portion therein; and a magnetic particle-resin composite layer including a core part filling the cavity and a cover part covering the insulating layer. The core part contains fine magnetic particles having an average particle diameter of 30 m or less, and the cover part contains the fine magnetic particles having the average particle diameter of 30 m or less and coarse magnetic particles having an average particle diameter greater than that of the fine magnetic particles.

A common mode filter in which at least one surface of all of external electrodes and ground electrodes are exposed to a first surface, at least one side of each of two of the external electrodes and at least one side of one of the ground electrodes contact a first side of the first surface, and at least one side of each of the external electrodes and the ground electrodes of which sides do not contact the first side contact a second side of the first surface, thereby making it possible to improve sticking strength and decrease a short-circuit phenomenon occurrence rate.

A common mode filter includes a first filter and a second filter formed by a magnetic coupling between primary coils and secondary coils, respectively, and connected in series. In the common mode filter, a resonance frequency f1 of the first filter and a resonance frequency f2 of the second filter are different from each other.

One embodiment provides an electronic control unit. The electronic control unit includes a housing and a noise filter. The housing includes an accommodating portion, and the accommodating portion includes a support portion. The noise filter includes an engaging portion, and at least part of the noise filter is housed in the accommodating portion of the housing. When the at least part of the noise filter is housed in the accommodating portion of the housing, the engaging portion is in engagement with the support portion.