The transmitting/receiving device has a polar modulator with a variable predistorter (11, 12) and an amplifier (8) which can be modulated, a reception path (25) which can be operated both during conventional reception and for the purposes of adjustment of the predistorter (11, 12) in order to determine a measurement signal (35) which is dependent on the output signal from the amplifier (8), and a coupling path for coupling of the reception path (25) to the output from the amplifier (8). A control and evaluation means (34, 36) is additionally provided for adjustment of the predistorter (11, 12).