Self-interference cancellation in chipless RFID readers for reading range enhancement

In this work, we studied the effect of self-interference cancellation in single-antenna monostatic chipless RFID readers on its reading range. Two theoretical limits for this range were obtained by taking into account both the signal and noise leaked from the transmitter. Moreover, a software-defined radio-based reader was implemented, whose performance was predicted to be restricted by the leakage signal power rather than the noise power, fact that was verified through measurements of a chipless tag. The experimental results also showed an improvement of more than four-times in the reading range through a 27-dB attenuation of the self-interference signal.