RFID (Radio Frequency Identification) is an automatic identification technology using radio waves. RFID readers are high-technology automatic identification devices based on wireless networks and enable noncontact identification; however, they cannot be applied beyond their radio communication range. Considering this, the present paper proposes multihop deployment of active RFID readers in order to extend a reader's radio coverage. Further, when a multitude of RFID readers are deployed in an RFID field, RFID tags are easily collected multiple times. Considering this situation, in this paper, we also propose reader collision avoidance for multihop deployment of active RFID readers. The proposed method not only avoids multiple reads from a tag but also extends the tag's lifetime. For experimental tests and performance evaluation, this study implements a multi-hop active RFID reader, which complies with the ISO/IEC 18000-7 standard.