Abstract: A non-radiating broadband microwave coupling device has a housing with first and second signal inputs and outputs, which are connected by respective first and second conductive connection line portions. A third output, also within the housing, is connected to these connection line portions by first and second semiconductor switches, which preferably are connected to parallel coupling line portions to provide inductive coupling. The semiconductor switches are selectively operable to close or switch the respective connection line through to the third output and open the other switch so that there is no significant power transfer to the third output. The connection line portions and the semiconductor switches are shielded within the housing. A corresponding terminator device has a termination resistor, which provides a ground connection for the coupling line portion not connected through to the output.