Passive Wake-active Standby Low-power Rfid System Analysis And Design

RFID, a non-contact automatic identification technology via radio frequency communication, has made tremendous development in recent years. Presently, it is accepted world widely as the one of the top 10 key technologies in 21st century owing to its significance in the theoretical research and practical application. Both radio and radar technology are employed to realize non-contact information transmission and object identification through inductive coupling or propagation coupling. RFID is widely used in distribution, public communication and entrance guiding nowadays and has a rather promising prospect in the near future.Based on the research on existing RFID system, this paper aims at transforming the traditional activating signal testing system through active ones into passive ones. To realize low power consumption of the standby model, by using the energy emitted by the reader to wakeup the tags, the project succeeds in overcoming the relatively greater standby power consumption of the traditional active tags and the shorter communication distance of the traditional passive tags. The RFID system under discussion consists of the reader and the tag; the wakeup and transmission signals are workable when the frequencies are both of the same or different types. The working pattern of the tag is as the follows: to switch the tag to be on standby model; to identify the signal received by the passive activating module; to turn on the switch and stimulate the active module; to turn off the switch after the communication; to switch the tag back to standby model. The battery does not conduct electricity into active module, thus under equal standby power consumption and leak current of the components, the power consumption are considered to be low without taking the leak current into consideration.In this paper, the working principle and system structure of the specific RFID system, namely one of the active RFID system with low standby power consumption owing to passive wakeup module, are elaborated. In addition, this paper presents the method to realize the tag IC and discrete device circuit of the system.