Detection of DVDs in a stack by an RFID system

The feasibility of identifying a large number of DVD devices in stack using a UHF RFID system is investigated in this paper. The physical and electrical parameters of packaged DVD devices are introduced, and three tag labeling methods for DVD cases together with the corresponding interrogating wave patterns, named as testing schemes “1”, “2”, “3” are explored through comprehensive experiments on a single tagged DVD in free space. An explanation of the experiment results is also given. One tagged DVD in the deep section of a DVD stack instead of in free space is tested under the three selected testing schemes respectively. The testing scheme with the best feasibility of identifying a large number of DVD devices in stack when all the DVDs are tagged is identified.