Comparison of multi-antenna configurations of an RFID reader with active carrier compensation

In this paper we compare different configurations of a multi-antenna Radio Frequency Identification (RFID) reader. This comparison is based on measurements of the receive parameters Signal-to-Noise Ratio (SNR) and Signal-to-Self-Interference Ratio (SSIR) obtained by our RFID research and development environment. We have conducted measurements with a commercially available tag in a static multi-path environment and eight different configurations for one transmitter and two receivers, with and without an active carrier compensation. We show the dependency of the SNR and the SSIR in four bi-static configurations and in four mono-static configurations. Furthermore, one of the bi-static configurations shows the principle capability of diversity combining via an active carrier compensation circuitry.