超高頻RFID標(biāo)簽低功耗時鐘電路的設(shè)計與實現(xiàn)
發(fā)布時間：2018-10-22 16:30
【摘要】：隨著國家物聯(lián)網(wǎng)戰(zhàn)略的推行,智能汽車、智能家居等新概念也相繼被提出。作為一種發(fā)展趨勢,物聯(lián)網(wǎng)給了我們很大的想象空間。物聯(lián)網(wǎng)的發(fā)展離不開射頻識別技術(shù)(Radio Frequency Identification,RFID)——一種利用射頻信號空間耦合實現(xiàn)非接觸式信息傳遞的技術(shù)。無源UHF RFID標(biāo)簽正是運用了這種技術(shù),才發(fā)揮出其識別距離遠(yuǎn),準(zhǔn)確性高,同時可識別多個目標(biāo)等受市場青睞的特點。無源UHF RFID標(biāo)簽芯片模擬前端和數(shù)字基帶能否良好的連接是非常關(guān)鍵的,因此,作為標(biāo)簽芯片內(nèi)連接二者的“橋”——時鐘電路就顯得尤為重要。本文主要針對UHF RFID標(biāo)簽芯片的功能需求,提出三種時鐘電路的設(shè)計,即環(huán)形振蕩器(Ring Oscillator)和弛豫振蕩器(Relaxation Oscillator)及改進(jìn)版馳豫振蕩器,通過嚴(yán)格的公式推導(dǎo),并對電路中所有細(xì)節(jié)做出了具體分析,深入研究了三種電路結(jié)構(gòu)及工作原理,最后都給出相應(yīng)的仿真結(jié)果,驗證電路的功能和性能。首先設(shè)計出一款新型的環(huán)形振蕩器,公式推導(dǎo)出頻率的表達(dá)式,從振蕩器頻率表達(dá)式可以看出,時鐘頻率的穩(wěn)定對工作電壓和電流的要求很高。其電路結(jié)構(gòu)主要包括:核心電路三級環(huán)形振蕩器,通過寄生電容的充放電形成正弦信號,并保持穩(wěn)定;電平轉(zhuǎn)換電路,提高由環(huán)形振蕩器產(chǎn)生的信號幅度;二分頻電路,調(diào)節(jié)信號的占空比,是頻率穩(wěn)定。在其前端的基準(zhǔn)電路中加入一個校準(zhǔn)電路,可對頻率進(jìn)行校準(zhǔn),改善因工藝引起的偏差。設(shè)計一個簡單的弛豫振蕩器,在實現(xiàn)該電路功能的前提下,對電路進(jìn)行具分析,為之后新版本打下基礎(chǔ)。該馳豫振蕩器結(jié)構(gòu)簡單,且在功能和性能上也有可取之處,例如溫度抑制能力和功耗方面都優(yōu)于環(huán)形振蕩器。通過公式推導(dǎo),可以知道,當(dāng)電容兩端的電壓和基準(zhǔn)電流之比為常數(shù)時,頻率跟基準(zhǔn)電流無關(guān)。改進(jìn)版馳豫振蕩器是針對上一版本做出的改進(jìn)的一款電路,通過提高電路對電源電壓、基準(zhǔn)電流和溫度的抑制能力來改善電路。本文設(shè)計了七位電阻比例自校準(zhǔn)電路,通過數(shù)字部分的邏輯運算,可以準(zhǔn)確校準(zhǔn)時鐘頻率,確保時鐘校準(zhǔn)精度要求的同時,克服了由于工藝的原因造成時鐘的偏差。這樣最終設(shè)計出電流電壓溫度抑制能力強(qiáng)、頻率精度高、偏差小的弛豫振蕩器,滿足了UHF RFID芯片系統(tǒng)的要求。
[Abstract]:With the implementation of the national Internet of things strategy, smart cars, smart home and other new concepts have been put forward. As a development trend, the Internet of things gives us a lot of imagination. The development of the Internet of things can not be separated from the RFID (Radio Frequency Identification,RFID), a technology to realize the non-contact information transmission by using the spatial coupling of radio frequency signals. With this technique, passive UHF RFID tags have the advantages of long recognition distance, high accuracy and recognition of multiple targets. Whether the analog front end and digital baseband of passive UHF RFID tag chip can be well connected is very important. Therefore, as the "bridge" of the tag chip connecting them, the clock circuit is very important. Aiming at the functional requirement of UHF RFID tag chip, this paper presents three kinds of clock circuits: ring oscillator (Ring Oscillator), relaxation oscillator (Relaxation Oscillator) and improved relaxation oscillator. All the details of the circuit are analyzed in detail, and three kinds of circuit structure and working principle are deeply studied. Finally, the corresponding simulation results are given to verify the function and performance of the circuit. First, a new type of ring oscillator is designed, and the expression of frequency is deduced. From the expression of frequency of oscillator, it can be seen that the stability of clock frequency requires high working voltage and current. Its circuit structure mainly includes: core circuit three-stage ring oscillator, through parasitic capacitance charge and discharge to form sinusoidal signal, and maintain stability; level conversion circuit, improve the signal amplitude produced by ring oscillator; two frequency division circuit, Adjust the duty cycle of the signal, the frequency is stable. A calibration circuit is added to the reference circuit of the front end, which can calibrate the frequency and improve the deviation caused by the process. A simple relaxation oscillator is designed, and the circuit is analyzed on the premise of realizing the function of the circuit, which lays the foundation for the new version. The relaxation oscillator is simple in structure and has some advantages in function and performance, such as temperature suppression ability and power consumption. By formula derivation, we can know that when the ratio of voltage to reference current at both ends of capacitor is constant, the frequency is independent of reference current. The improved relaxation oscillator is an improved circuit for the previous version, which improves the circuit by improving its ability to suppress the supply voltage, reference current and temperature. In this paper, a seven-bit resistor proportional self-calibration circuit is designed. Through the logic operation of the digital part, the clock frequency can be accurately calibrated, and the clock calibration accuracy can be ensured, and the clock deviation caused by the process can be overcome at the same time. Finally, a relaxation oscillator with strong current voltage temperature suppression ability, high frequency precision and small deviation is designed, which meets the requirements of UHF RFID chip system.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN402;TP391.44
本文編號：2287692
[Abstract]:With the implementation of the national Internet of things strategy, smart cars, smart home and other new concepts have been put forward. As a development trend, the Internet of things gives us a lot of imagination. The development of the Internet of things can not be separated from the RFID (Radio Frequency Identification,RFID), a technology to realize the non-contact information transmission by using the spatial coupling of radio frequency signals. With this technique, passive UHF RFID tags have the advantages of long recognition distance, high accuracy and recognition of multiple targets. Whether the analog front end and digital baseband of passive UHF RFID tag chip can be well connected is very important. Therefore, as the "bridge" of the tag chip connecting them, the clock circuit is very important. Aiming at the functional requirement of UHF RFID tag chip, this paper presents three kinds of clock circuits: ring oscillator (Ring Oscillator), relaxation oscillator (Relaxation Oscillator) and improved relaxation oscillator. All the details of the circuit are analyzed in detail, and three kinds of circuit structure and working principle are deeply studied. Finally, the corresponding simulation results are given to verify the function and performance of the circuit. First, a new type of ring oscillator is designed, and the expression of frequency is deduced. From the expression of frequency of oscillator, it can be seen that the stability of clock frequency requires high working voltage and current. Its circuit structure mainly includes: core circuit three-stage ring oscillator, through parasitic capacitance charge and discharge to form sinusoidal signal, and maintain stability; level conversion circuit, improve the signal amplitude produced by ring oscillator; two frequency division circuit, Adjust the duty cycle of the signal, the frequency is stable. A calibration circuit is added to the reference circuit of the front end, which can calibrate the frequency and improve the deviation caused by the process. A simple relaxation oscillator is designed, and the circuit is analyzed on the premise of realizing the function of the circuit, which lays the foundation for the new version. The relaxation oscillator is simple in structure and has some advantages in function and performance, such as temperature suppression ability and power consumption. By formula derivation, we can know that when the ratio of voltage to reference current at both ends of capacitor is constant, the frequency is independent of reference current. The improved relaxation oscillator is an improved circuit for the previous version, which improves the circuit by improving its ability to suppress the supply voltage, reference current and temperature. In this paper, a seven-bit resistor proportional self-calibration circuit is designed. Through the logic operation of the digital part, the clock frequency can be accurately calibrated, and the clock calibration accuracy can be ensured, and the clock deviation caused by the process can be overcome at the same time. Finally, a relaxation oscillator with strong current voltage temperature suppression ability, high frequency precision and small deviation is designed, which meets the requirements of UHF RFID chip system.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN402;TP391.44
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 陳瑩梅,王志功,朱恩,馮軍,章麗,熊明珍;一種高工作頻率、低相位噪聲的CMOS環(huán)形振蕩器[J];光電子·激光;2004年10期
，本文編號：2287692
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