A device for generating and/or processing a signal, and a method for ascertaining an adjustment of a device for processing or generating a signal. The method includes the steps: generating a transmission signal or a test signal with the aid of a signal device of a device; separating first signals, which come to the signal device from an interface device of the device, from second signals which come to the interface device from the signal device, the interface device being coupleable or coupled to a transmitting and/or receiving antenna; and outputting the first and the second signals separately from one another.