Aspects of this disclosure relate to a radio frequency coupler and an adjustable termination impedance circuit. In an embodiment, an apparatus includes a radio frequency coupler and a termination impedance circuit configured to provide an adjustable termination impedance, in which the termination impedance circuit includes two switches and a passive impedance element in series between a reference potential and a selected port of the RF coupler, the selected port being one of an isolated port of the RF coupler or a coupled port of the RF coupler.