The present invention relates to an I/Q demodulator (21) comprising a n-port structure (1,16) is provided, wherein n is an integer value of 4,5 or 6. The demodulator (21) is supplied at a first input (3) with a RF signal (2) which has to be demodulated. At a second input (5) it is supplied with a second RF signal (4). The n-2 output signals (6) are detected by power sensors (7). After low pass filtering (14) the output signals of the power sensors (7) are multiplexed by a multiplexing means (8).