發(fā)布時(shí)間：2019-01-05 06:05

【摘要】：無(wú)源超高頻射頻識(shí)別(UHF RFID)技術(shù)可以在非接觸的條件下實(shí)現(xiàn)對(duì)目標(biāo)對(duì)象的自動(dòng)識(shí)別,是物聯(lián)網(wǎng)的核心支撐技術(shù)之一。閱讀距離遠(yuǎn)、通信速率快、適應(yīng)物體高速運(yùn)動(dòng)等優(yōu)點(diǎn),是工作于超高頻頻段的射頻識(shí)別系統(tǒng)相對(duì)于其它頻段的射頻識(shí)別技術(shù)而言所具有的優(yōu)勢(shì)。本文首先對(duì)UHF RFID的系統(tǒng)組成、工作原理進(jìn)行了簡(jiǎn)單的介紹,并對(duì)正向和反向的能量與數(shù)據(jù)傳輸方式進(jìn)行了介紹,再此基礎(chǔ)上,通過(guò)分析計(jì)算,得出了標(biāo)簽芯片的功耗是限制通信距離的主要因素。然后,本文提出了一種完整的標(biāo)簽芯片系統(tǒng)方案,并分別對(duì)射頻前端、模擬前端、數(shù)字基帶和存儲(chǔ)器做了詳細(xì)的介紹。特別的,本文提出了一種全CMOS超高效率的閾值補(bǔ)償倍壓整流電路,其在可能的輸入能量范圍內(nèi),倍壓整流電路的效率值都不低于50%。通過(guò)分析計(jì)算,結(jié)合存儲(chǔ)器的需求,得出存儲(chǔ)器讀操作高壓管控制電壓是限制芯片通信距離的主要因素,在此基礎(chǔ)上,提出了一種帶有倍壓功能的穩(wěn)壓電路,使標(biāo)簽的讀取距離由5.1米擴(kuò)展到了6.8米。當(dāng)射頻識(shí)別技術(shù)與傳感器技術(shù)相結(jié)合時(shí),其應(yīng)用場(chǎng)合將會(huì)得到非常大的擴(kuò)展�；诖�,在分析了傳統(tǒng)溫度傳感器應(yīng)用于UHF RFID標(biāo)簽芯片中時(shí)面臨的問(wèn)題后,本文提出了一種適用于UHF RFID標(biāo)簽芯片的溫度傳感器,采用了雙振蕩器的結(jié)構(gòu),提高了傳感器的魯棒性。并且,采用了時(shí)分模式,在系統(tǒng)上電和命令到來(lái)之間的時(shí)間間隙進(jìn)行溫度檢測(cè),因此并不影響標(biāo)簽的通信距離。通過(guò)測(cè)試,在不影響通信距離的前提下,溫度傳感器在-40℃到85℃范圍內(nèi),最大誤差為±1.5℃。再次,考慮到通信的安全性,本文在分析了常用的幾種數(shù)字方式產(chǎn)生隨機(jī)數(shù)的方案,并總結(jié)出其缺點(diǎn)后,提出了兩種適用于UHF RFID應(yīng)用的隨機(jī)數(shù)發(fā)生器。一種采用電阻的熱噪聲作為隨機(jī)源,通過(guò)放大器,由D觸發(fā)器進(jìn)行采樣輸出。放大器采用低功耗技術(shù),整體隨機(jī)數(shù)發(fā)生器的功耗僅為800nW。另一種隨機(jī)數(shù)發(fā)生器是在前文提出的溫度傳感器基礎(chǔ)上,利用時(shí)鐘抖動(dòng)得到隨機(jī)數(shù),與溫度傳感器類似,采用時(shí)分模式,并不影響標(biāo)簽通信距離。最后,本文提出的標(biāo)簽芯片在中芯國(guó)際CMOS 0.18μm EEPROM 2P4M工藝下,采用多項(xiàng)目晶圓(MPW)的方式來(lái)實(shí)現(xiàn)。采用兩種方式對(duì)芯片進(jìn)行了詳細(xì)的測(cè)試。首先,采用芯片綁定在印制版(COB)封裝,標(biāo)簽與閱讀器采用有線的方式進(jìn)行連接,通過(guò)示波器對(duì)波形進(jìn)行觀察,給出了一些關(guān)鍵信號(hào)的波形。其次,采用倒裝封裝,模擬真實(shí)應(yīng)用場(chǎng)景,對(duì)標(biāo)簽進(jìn)行測(cè)試,結(jié)果顯示,最遠(yuǎn)讀取距離大于6.8米,最大可寫入距離為1.8米,平均讀取速率達(dá)到了66個(gè)/s。
[Abstract]:Passive UHF radio frequency identification (UHF RFID) technology is one of the core supporting technologies in the Internet of things (IoT), which can realize the automatic identification of the target object under the condition of non-contact. The advantages of long reading distance, fast communication rate and high speed motion of objects are the advantages of RFID system which works in UHF band compared with other RFID technology. In this paper, the system composition and working principle of UHF RFID are introduced briefly, and the forward and reverse energy and data transmission modes are introduced. It is concluded that the power consumption of the tag chip is the main factor limiting the communication distance. Then, a complete tag chip system is proposed, and the RF front-end, analog front-end, digital baseband and memory are introduced in detail. In particular, a threshold compensated double voltage rectifier circuit with full CMOS ultra-high efficiency is proposed. In the range of possible input energy, the efficiency of voltage doubling rectifier circuit is not less than 50. Through analysis and calculation, combined with the demand of memory, it is concluded that the control voltage of high voltage tube in memory read operation is the main factor limiting the communication distance of chip. On the basis of this, a voltage stabilizing circuit with voltage doubling function is proposed. Extended the read distance of the tag from 5.1 m to 6.8 m. When RFID and sensor technology are combined, the application of RFID will be greatly expanded. Based on this, after analyzing the problems of traditional temperature sensor applied in UHF RFID tag chip, this paper presents a temperature sensor suitable for UHF RFID tag chip, which adopts the structure of double oscillator. The robustness of the sensor is improved. Moreover, time division mode is used to detect the temperature between the time interval between the power supply and the arrival of the command, so the communication distance of the label is not affected. The results show that the maximum error of the temperature sensor is 鹵1.5 鈩，

本文編號(hào)：2401378