Circuit arrangement with improved decoupling

A circuit arrangement, comprising:

• a device comprising a closed signal path, the closed signal path connected to a first port, to a second port and a third port, the closed signal path comprising a directed signal flow with respect to a signal applied to one of the first, second and third port;
• a first circuit configured to be coupled to the third port, the first circuit comprising a plurality of paths;
• a tunable matching network connected to the second port and configured to be coupled to a second circuit, the tunable matching network having a directional coupler configured to decouple a forward signal from a forward direction and a reflection signal from a reflection direction, and the matching network configured to calculate a reflection coefficient from the forward signal and the reflection signal, the reflection coefficient representing information about a match or mismatch with an impedance of the second circuit to an impedance of a selected path of the plurality of paths of the first circuit;
• and
• wherein the first port comprises a differential input.