This application relates to an independent active electromagnetic interference filter module. In one aspect, the filter module includes a first element group including a noise sensing unit provided to sense electromagnetic noise, and a second element group including a compensating unit provided to generate a compensation signal for the electromagnetic noise. The first group and the second group may be respectively mounted on different substrates. According to some embodiments, the filter module can reduce a volume of each element constituting an electromagnetic interference filter module, implement a single modularization of a compact structure. The filter module can also improve electromagnetic interference noise reduction performance and a manufacturing method thereof.

Radio frequency filtering circuitry blocks certain frequencies in an outgoing signal so that the signal may be transmitted over a desired frequency. The radio frequency filtering circuitry includes a first inductor having a first coil and a second inductor coupled to and disposed within the first coil. The second inductor has a second coil and a third coil symmetrical to the second coil. When current is applied to the radio frequency filtering circuitry, the current in the second coil causes a first induced current in the first coil and the current in the third coil causes a second induced current in the first coil, wherein the second induced current is approximately equal in magnitude and opposite in direction to the first induced current. As such, the second induced current may compensate for the first induced current.

In a communications system that conducts differential data via a pair of wires, AC common mode noise is undesirably coupled to the wires in a noisy environment. A hybrid common mode choke (HCMC) attenuates the AC common mode noise while passing the differential data to a PHY. The HCMC includes a CMC (windings with the same polarity) and a differential mode choke (windings with opposite polarities). The CMC attenuates the AC common mode noise, and the DMC passes the attenuated AC common mode noise to termination circuitry to eliminate it. Also disclosed is a technique for Kelvin sensing the DC voltage at the pair of wires, in a PoDL system, by detecting the voltage on wires that do not carry DC current, so as to provide a more accurate measurement.

A filter for electromagnetic noise comprising: a printed circuit board (5) having conductor tracks, having a first side and having a second side opposite the first side; a first busbar (1), which is secured on the first side of the printed circuit board (5) and is electrically connected to at least one of the conductor tracks; and a second busbar (2), which is secured on the second side of the printed circuit board (5) and is electrically connected to at least one of the conductor tracks. The printed circuit board (5) is arranged between the first busbar (1) and the second busbar (2) for the insulation thereof.

Disclosed herein is a common mode filter that includes first and second terminal electrodes provided on the first flange part, third and fourth terminal electrodes provided on the second flange part, a first wire wound around the winding core part and having one end connected to the first terminal electrode and other end connected to the third terminal electrode, and a second wire wound around the winding core part and having one end connected to the second terminal electrode and other end connected to the fourth terminal electrode. The winding core part includes a first winding region, a second winding region, and a third winding region positioned between the first and second winding regions in the axial direction. The first and second wires are bifilar-wound in the first and second winding regions and layer-wound in the third winding region.

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.

A filtering circuit includes at least two common-mode filters that are electrically coupled in series and magnetically coupled. The first common-mode filter includes first and second spiral inductors that are positively magnetically coupled and electrically isolated from each other. The second common-mode filter includes third and fourth spiral inductors that are positively magnetically coupled and electrically isolated from each other. The first and third spiral inductors are electrically connected in series and negatively magnetically coupled. Likewise, the second and fourth spiral inductors are electrically connected in series and negatively magnetically coupled.

An embodiment of the present invention is directed to an integrated electromagnetic compatibility (EMC) filter and power line communication (PLC) interface. The EMC filter and PLC interface comprises a first filter winding and a second filter winding configured as a common mode choke; and a two-part winding on the common mode choke, wherein the two-part winding comprises (i) a first winding coupled proximate the first filter winding and (ii) a second winding coupled proximate the second filter winding, wherein the first winding and the second winding have an equal number of turns, and wherein phasing of the first winding is reversed with respect to the second winding.

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.

The invention is directed towards a power source interface module for electronic circuits supplied by power from a power source as well as a power supply arrangement for electronic circuits comprising such a power source interface module. The module comprises a first circuit board carrying components, the first circuit board comprising a number of stacked circuit board layers as well as at least two openings, at least a part of a filter comprising at least one pair of magnetically coupled inductive coils, a core with two core legs, each core leg stretching through a corresponding opening in the circuit board, wherein each coil is wound around a corresponding core leg, the turns of the coils stretch through the circuit board layers, and each layer between an upper outer layer and a lower outer layer comprises at least a part of one turn.