Design And Implementation Of Power Module Of Passive UHF RFID Tag Chip

Passive Ultra High Radio Frequency Identification(UHF RFID)is a non-contact automatic identification technology,which identifys objects and captures date information by using radio frequency signal,as a result,it completes the data sampling and processing.Due to its small size,large amount of information storage,long read-write distance etc.UHF RFID is widely used in retail,logistics and other industries.the power supply module as the energy source of UHF RFID that directly determines the read-write distance of tag chip.Therefore,the study of the power supply module is particularly important.This paper introduces a design of the high-performance power module in UHF RFID tag chip,including rectifier circuit,bandgap reference circuit,LDO circuit,the pressure limiting circuit and a voltage switching circuit.For the first three circuits,the research follows a way like this,which bases on operating principle of the circuits,and then shows some relating key points or indexes of design,finally puts forward the corresponding design and simulation analysis.The first part is doing some research on rectifier circuit,and presents a design of a five stage voltage-multiplying rectifier circuit with high efficiency,when input voltage is 0.5V and load of circuit is 200 K,output voltage is up to 3V and rectifier efficiency is 52%.what'more,there are two more rectifier circuits being simulating and analysising.The second part is about bandgap reference circuit,three kinds of bandgap reference circuit has advantages of low power and lower voltage are presented.Comparing the performance,the chip chooses a circuit with a lowest input voltage of 1V and its power is 550 nW,temperature coefficient is only 84ppm/?.The third part is carrying on a detailed analysis of LDO circuit,which focus on circuit compensation mode,for instance,zero compensation,miller compensation,advanced phase compensation and zero or pole tracking compensation.two kinds of LDO circuits are designed and key points of design are analyzed in detail.The last part anailysis the pressure limiting circuit and a voltage switching circuit.Finally,the chip is tested with fabricated in TSMC 0.18?m process,which contains about its sensitivity and some specifications about its the power supply module.The read sensitivity of the best tags add to-14.68 dBm,at the same time,the write sensitivity also add to-11.68 d Bm.The result shows good performance of the power supply module.