Multi-channel filter comprising plural elongate signal tracks covered by electromagnetically absorbing material and the signal tracks are separated by elongate shielding tracks

A multi-channel filter comprising:

• a printed circuit board comprising:
• a plurality of first elongate signal tracks, each first elongate signal track formed by an electrically conducting path on a first surface of the printed circuit board, each first signal track is not galvanically connected to any other first signal track,
• one or more first elongate shielding tracks, each first elongate shielding track formed by an electrically conducting or absorbing path on the first surface, where each of the plurality of first elongate signal tracks is separated from a neighboring first elongate signal track by one of the one or more first elongate shielding tracks,
• a first electrically conducting or absorbing layer on a second surface of the printed circuit board, the first and second surfaces being opposite surfaces of the printed circuit board, and
• a first electromagnetically absorbing material covering the plurality of first elongate signal tracks.