Patent ID: 8576027

Claim:
A differential-common mode resonant filter, comprising: a multilayer board comprising two or more conductor layers; a resonator formed by ground plates disposed one under another in said conductor layers and ground vias connected to said ground plates; two signal vias disposed within said resonator, passing through said resonator and isolated from said ground plates by clearance holes; two terminals connected to said two signal vias to receive differential-mode and common-mode signals; wherein said resonator establishes a resonant effect on said two signal vias at predetermined frequencies by means of horizontal dimensions of said resonator and a first isolating material disposed between said ground plates, wherein said resonator has a first face of symmetry perpendicular to said ground plates, and wherein said two signal vias are disposed symmetrically with respect to said first face of symmetry at a distance from said first face of symmetry providing a separation of said differential-mode and common-mode signals in a frequency domain.