Abstract: A switchable capacitor assembly is provided that includes a first terminal, a second terminal, a first resistor, a first switch, a capacitor operatively connected between the first switch and the second terminal, a voltage follower operatively connected between the first terminal and the first resistor, the first resistor being operatively connected between the voltage follower and the first switch, and a second switch configured to short circuit the first resistor. The first switch is configured to toggle between two states including a first state where the switch operatively connects the capacitor to the first resistor and a second state where the switch operatively connects the capacitor to the first terminal.

Abstract: A filter comprising a flexible PCB with one or more signal tracks on one side. A electromagnetically absorbing material covers the signal tracks. An insulating material may be provided between the signal tracks and the electromagnetically absorbing material. The PCB is then folded or rolled to take up less space. The PCB may be first folded and then rolled to have both ends of the signal tracks available at the outer portion of the roll.

Abstract: A multi-channel filter with a PCB with a first side with signalling tracks and shielding tracks between neighbouring signalling tracks. On the second side, a conductive layer is provided. The signalling tracks are covered by an electromagnetically absorbing material, such as a powder of an electrically conducting material is provided. The filter may have sections with reversed structure where the conductors are on the second side and the layer on the first side, where the conductors on opposite sides are interconnected. The filter may be rolled or folded.