Smart antenna system using five-port reflectometer

The difficult design of variable phase shifters for smart antenna applications makes digital beamforming systems an interesting way for future communication systems that aim to provide better network performance. Five-port reflectometers use a third redundant mixer to decrease the system dependency from the phase and amplitude unbalance of local oscillators. We introduce a digital beamforming system for reception array using the five-port technique which performs a direct conversion of RF signals. The system performance is tested by measuring its bit error rate for different number of antenna array elements.