An All Passive Compact Six-port Receiver

A non-coherent passive six-port receiver system is presented for accurate amplitude, phase and frequency measurement of a RF signal. The system uses the six-port network and a new wideband phase delay line with known phase profile. The phase delay unit uses a number of openstubs connected to a microstrip line. Detail design steps of the phase delay line is presented. The whole receiver is fabricated in PCB technology. No local oscillator or DC biasing are used. Thus, it is an all-passive system, which does not require any power source. It can be used as a real time and fast demodulator for both analog and digital signals.