Research On Key Technologies Of RF/Analog Front End Of Passive UHF RFID Tag Chip

With the rapid development of Internet of things,radio frequency identification(RFID)technology has been a lot of applications.Among them,passive UHF RFID tag chip with high accuracy,storage capacity,reusable,non-contact read and write,can identify high-speed moving objects,unique identification code,which can identify multiple identification objects,etc.,has a very broad Application market.As one of the most important modules in the passive tag chip,the performance of RF front-end circuit directly determines the main performance index of the tag chip.This paper is devoted to the research of the RF front-end key technology of passive UHF RFID tag chip and the realization of related circuit.In this paper,the positive design,system-level model derived from the key technology,and thus the circuit design and performance analysis.In the key technology,the energy model analysis shows that the read and write sensitivity is proportional to the distance;the backscattering technique is obtained from the signal model analysis;and the anti-collision technology is applied in the RF front end.The first of these three key technologies,the first ultra-high read and write sensitivity research mainly from three aspects: to expand the work of bandwidth,improve energy conversion efficiency and reduce internal energy loss.Based on the above,we carried out the automatic impedance matching circuit design and implementation,rectifier design and implementation,and low power design analysis.Simulation and follow-up test results show that,compared with the previous-chip version of the label sensitivity increased by 4dBm.The second key technology is the backscatter technique.Firstly,the backscatter principle of UHF tags based on autonomous military standard is analyzed in detail,namely ASK modulation and PSK modulation.According to the above principle,two modulation circuits are designed,And carried on the simulation analysis and layout design.The third key technology is anti-collision technology.We know that multi-target identification is the main characteristics of RFID systems,which can not avoid the anti-collision design of the label.Tag RF simulation front-end technology involved in the anti-collision technology is the real number of random number generator circuit,so we designed a true random number generator circuit,and the simulation analysis and related testing.The test results show that the average read sensitivity of this tag chip is-17.5 dBm,the average write sensitivity is-15.5 dBm,and its rectifier rectification efficiency is about 60%.The overall performance of the tag chip reaches the domestic first-class level.