Common-mode filter

Patent metadata

Field	Value
Publication number	US-11025219-B2
Application number	US-201916258883-A
Country	US
Kind code	B2
Filing date	Jan 28, 2019
Priority date	Jan 29, 2018
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

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.

First claim

The invention claimed is:

1. A circuit, comprising at least two common-mode filters electrically in series and magnetically coupled, wherein said at least two common-mode filters comprise:
at least one first inductive element and at least one second inductive element formed by planar conductive windings that are electrically in series;
wherein the planar conductive windings electrically in series of the at least one first inductive element and at least one second inductive element are concentric; and
at least one third inductive element and at least one fourth inductive element formed by planar conductive windings that are electrically in series;
wherein the planar conductive windings electrically in series of the at least one third inductive element and at least one fourth inductive element are concentric.

2. The circuit of claim 1 , wherein the magnetic coupling between two electrically neighboring common-mode filters of the at least two common-mode filters is negative.

3. The circuit of claim 1 , wherein each common-mode filter comprises two inductive elements that are magnetically coupled.

4. The circuit of claim 3 , wherein the magnetic coupling between the two inductive elements of the same common-mode filter is positive.

5. The circuit of claim 1 , wherein:
the at least one first inductive element and the at least one third inductive element are electrically insulated one from each other and magnetically coupled to each other by being concentric; and
the at least one second inductive element and the at least one fourth inductive element are electrically insulated one from each other and magnetically coupled to each other by being concentric.

6. The circuit of claim 1 , wherein respective phase points of the at least one first inductive element, the at least one second inductive element, the at least one third inductive element, and the at least one fourth inductive element are oriented on a same side.

7. The circuit of claim 1 , wherein the at least one first inductive element and the at least one third inductive element have approximately a same inductance value.

8. The circuit of claim 1 , wherein the at least one second inductive element and the at least one fourth inductive element have approximately a same inductance value.

9. The circuit of claim 1 , wherein input terminals and/or output terminals of the circuit are connected to diodes that are grounded.

10. The circuit of claim 1 , wherein the planar conductive windings of the at least one first inductive element and the at least one second inductive element are in the same plane.

11. The circuit of claim 10 , wherein a rotation direction for current flow of the planar conductive windings in the same plane are inverted.

12. The circuit of claim 1 , wherein the planar conductive windings of the at least one first inductive element and the at least one second inductive element are in two overlapping planes.

13. The circuit of claim 1 , wherein a first planar conductive winding and a third planar conductive winding, respectively forming the at least one first inductive element and the at least one third inductive element, are made in conductive levels stacked with at least one insulating level.

14. The circuit of claim 13 , wherein the first planar conductive winding and the third planar conductive winding are vertically aligned one to the other.

15. The circuit of claim 13 , wherein a second planar conductive winding and a fourth planar conductive winding, respectively forming the at least one second inductive element and the at least one fourth inductive element, are vertically aligned one to the other.

16. A common mode filter, comprising:
a first input node;
a second input node;
a first output node;
a second output node;
a first intermediate node;
a second intermediate node;
a first spiral inductor that winds in a first direction and is coupled between the first input node and the first intermediate node;
a second spiral inductor that winds in the first direction and is coupled between the second input node and the second intermediate node;
a third spiral inductor that winds in a second direction opposite the first direction and is coupled between the first intermediate node and the first output node; and
a fourth spiral inductor that winds in the second direction and is coupled between the second intermediate node and the second output node;
wherein the first and third spiral inductors are coplanar and concentric; and
wherein the second and fourth spiral inductors are coplanar and concentric.

17. The circuit of claim 16 , wherein the first and second input nodes and/or the first and second output nodes are connected to diodes that are grounded.

18. The common mode filter of claim 16 , wherein the first through fourth spiral inductors are concentric.

19. The common mode filter of claim 16 , wherein the first and second spiral inductors are positively magnetically coupled and wherein the third and fourth spiral inductors are positively magnetically coupled.

20. The common mode filter of claim 19 , wherein the first and third spiral inductors are negatively magnetically coupled and wherein the second and fourth spiral inductors are negatively magnetically coupled.

21. A circuit, comprising:
a first common-mode filter formed by planar conductive windings; and
a second common-mode filter formed by planar conductive windings;
wherein the planar conductive windings of the first and second common-mode filters are electrically connected in series; and
wherein the planar conductive windings that are electrically connected in series are concentric and in a same plane.

22. The circuit of claim 21 , wherein the first and second common-mode filters have a negative magnetic coupling.

23. The circuit of claim 21 , wherein the planar conductive windings of each of the first and second common-mode filters are magnetically coupled.

24. The circuit of claim 23 , wherein the magnetic coupling between the planar conductive windings of each of the first and second common-mode filters is positive.

25. The circuit of claim 21 , wherein rotation directions for current flow of the planar conductive windings that are electrically connected in series and in the same plane are inverted.

26. The circuit of claim 21 , wherein input terminals and/or output terminals of the circuit are connected to diodes that are grounded.

27. The circuit of claim 21 , wherein all of the planar conductive windings of the first and second common-mode filters are concentric.

28. A circuit, comprising:
a first common-mode filter formed by planar conductive windings; and
a second common-mode filter formed by planar conductive windings;
wherein the planar conductive windings of the first and second common-mode filters are electrically connected in series; and
wherein the planar conductive windings that are electrically connected in series are concentric and in two overlapping planes.

29. The circuit of claim 28 , wherein the first and second common-mode filters have a negative magnetic coupling.

30. The circuit of claim 28 , wherein the planar conductive windings of each of the first and second common-mode filters are magnetically coupled.

31. The circuit of claim 30 , wherein the magnetic coupling between the planar conductive windings of each of the

Assignees

• St Microelectronics Tours Sas

Inventors

• Concord Joel

Classifications

• H03H7/17

  Structural details of sub-circuits of frequency selective networks · CPC title

• H01P1/20381

  Special shape resonators · CPC title

• H03H7/427 Primary

  Common-mode filters (H02J3/01 and H02M1/126 takes precedence) · CPC title

• H01P1/203 Primary

  Strip line filters · CPC title

• H03H7/01

  Frequency selective two-port networks · CPC title