A coupling element is disclosed, comprising four coils that are arranged such that each one of the coils extends both in a first layer and a second layer. The first layer and the second layer are stacked with respect to each other and separated by an intermediate dielectric layer. The layout of each layer is configured to provide a transformer coupling between a first one and a third one of the coils, and between a second one and a fourth one of the coils. Further, the first coil and the second coil, and the third coil and the fourth coil, respectively, are routed so as to allow a differential signaling. A semiconductor device and a differential hybrid coupler comprising the coupling element are also disclosed.