Patent ID: 9203372
Filing Date: 2015-12-01
Classification: H03H

Abstract:
1. A common mode filter comprising: first and second spiral patterns that are provided on a first plane and that are connected to each other in series; and third and fourth spiral patterns that are provided on a second plane different from the first plane and that are connected to each other in series, wherein the first and third spiral patterns overlap each other in a planar view so as to be magnetically coupled with each other, thereby constituting a first common mode filter element, the second and fourth spiral patterns overlap each other in the planar view so as to be magnetically coupled with each other, thereby constituting a second common mode filter element, each winding direction of the first and second spiral patterns is set to cancel out magnetic fluxes of the first and second spiral patterns between each other, each winding direction of the third and fourth spiral patterns is set to cancel out magnetic fluxes of the third and fourth spiral patterns between each other, an outer peripheral end of the first spiral pattern is connected to an outer peripheral end of the second spiral pattern, an outer peripheral end of the third spiral pattern is connected to an outer peripheral end of the fourth spiral pattern, a direction in which the first spiral pattern is wound from an inner peripheral end thereof toward the outer peripheral end thereof is the same as a direction in which the second spiral pattern is wound from the outer peripheral end thereof toward an inner peripheral end thereof, and a direction in which the third spiral pattern is wound from an inner peripheral end thereof toward the outer peripheral end thereof is the same as a direction in which the fourth spiral pattern is wound from the outer peripheral end thereof toward an inner peripheral end thereof, a number of turns in the first spiral pattern is larger than a number of turns in the second spiral pattern, and a number of turns in the third spiral pattern is larger than a number of turns in the fourth spiral pattern.