QPSK demodulator based on six port junction

This article presents two different architectures of six port junctions operating at 2.45 GHz. One of those structures was based on a "branch line" coupler technology; the second junction is based on a circular coupler. both couplers have inputs connected to a Wilkinson power divider and the couplers used are hybrid couplers 90 degrees/3dB. The simulation was performed using the Agilent ADS software technologies. The comparative study between the two junctions showed that a six ports junction using a circular coupler has better performance in terms of phase difference, loss, performance, reflection and isolation. The chosen configuration has been connected to power detectors to show its performance as a demodulator circuit.