A Fabrication Method for Integrated Filter Elements With Inductance Cancellation

This paper outlines a fabrication method for integrated filter elements. An integrated filter element is a three- (or more) terminal device comprising a capacitor and coupled air-core magnetic windings, in which the magnetic windings cancel the effects of capacitor parasitic inductance. This provides greatly enhanced filtration performance over a capacitor alone. Methods for designing and forming cancellation windings are described, along with means for repeatable interconnection with the capacitor and encapsulation of the filter element. The high performance and repeatability of filter elements fabricated with the proposed method are demonstrated with several examples.