Wide-band RF receiver using the "five-port" technology

Many experiments have been proposed in order to demonstrate that the "five-port" system performs a homodyne demodulation . The large bandwith of a five-port circuit is its main advantage. However, this kind of system must be calibrated for each frequency in order to carry out the inphase and quadrature demodulation. The subject of this paper is to show a new calibration method. This technique uses the training sequence received at each received burst of data to calibrate the five-port system. A method to synchronize the receiver with the training sequence of each burst is presented. We also study the effect of adjacent channels and cochannel interferer on the calibration. Results on quaternary phase-shift keying demodulation are presented.