The maximization of code capability of surface acoustic wave radio frequency identification

Surface Acoustic Wave(SAW) Radio Frequency Identification(RFID) has its advantages over IC based RFID,but it has difficulties to possess the code capacity large enough for most practical usage.Especially,in the frequency band of 922.5 MHz,the permitted bandwidth is only 5 MHz,which restricts the reflectors separated each other distantly,as the results,the code capacity becomes much less in the same dimension of the chip.In order to break through it,in the paper,we report a new system,which enables one to fabricate a tag with code capacity 3.5×10⁷ within a chip length of 8 mm.The result demonstrates a bright prospect of SAW RFID for wide applications.