Research And Application Of LF Wake-up Technology In Semi-active RFID

The poxwer consumption of wireless communications equipment has always been a key issue in the development of wireless products.In order to extend the life of lithium batteries,you need to reduce the power consumption of' wireless devices.So people give the use of low-power work program,reducing unnecessary wake-up.to achieve low power consumption.Theis mode of operation sends the low-frequcncy signal to the low-frequency wake-up module,and then analyzing and generating an interrupt signal or reset signal,this signal is used to wake up the dormant terminal device.Based on the principle of low-frequency wake-up technology.this article puts forward the technical solution of AS3933 low-frequencv wake-up chip based on Norwegian Austrian Microelectronics Company.and has gone on a lot of debugging and testing.The aim is to design the equipment which can meet the requircements of system design index.Based on the low-frequency wake-up technology,this article designs a long-distance data communication system based on TI's CC2500 wireless chip.which allows the system to uploacd data and analyze it in real time after being awakened.The mainly system has AS3933 low-frequency wake-up module,CC2500 high-frequency transceiver module.MCU control module and power supply module.The system in the normal status is in a low power state.The current is about 7?9uA.When the head end device close to the system.AS3933 module will receive low frequcncy signal,and then MCU will give an interrupt siognal to CC2500 transceiver module,CC2500 will be reqLuired to transfer data to complete the data exchange.This design greatly reduces the machine system standby current,and can also to achiceve long-distance transmission of data capacity.This low-frequcncy wake-up mechanism can be well applied to semi-active RFID.Compared to traditional passive and active RFID,scmi-active power consumption can be as low as 7uA.with lower than the active power consumption(the general active power consumption will be moree then 100uA).Has a communication distance farther than the passive RFID(typically the passive RFID communication distance of less than 0.5m,blut semi-active RFID can reach 100m).So in contrast,semi-active RFID advantage is very obvious.Throuugh the system design,simulation of inverted F antenna,matching of the balun circuit,the testing of the whole system and application in the product,this product can achieve the desired function,and meet the requirements of low power consumption.