【摘要】：北斗衛(wèi)星導(dǎo)航定位系統(tǒng)是我國(guó)獨(dú)立自主研發(fā)的全球衛(wèi)星定位和通信導(dǎo)航系統(tǒng)，在如交通導(dǎo)航、授時(shí)、地質(zhì)勘探、地理測(cè)繪等軍用作業(yè)及民用生活中存在廣闊的應(yīng)用空間。衛(wèi)星導(dǎo)航定位數(shù)據(jù)經(jīng)過(guò)的無(wú)線信道傳輸距離遠(yuǎn)、電磁干擾復(fù)雜，又由于采用擴(kuò)頻技術(shù)，使得北斗射頻信號(hào)的輻射功率譜極低，淹沒(méi)于噪聲基底以下，因此對(duì)北斗地面射頻接收前端的接收靈敏度及自動(dòng)增益調(diào)節(jié)動(dòng)態(tài)范圍性能等方面提出了較苛刻的要求。為了使北斗衛(wèi)星地面導(dǎo)航定位系統(tǒng)可以適應(yīng)各種惡劣復(fù)雜的地面作業(yè)環(huán)境，，用于射頻接收前端電路的自動(dòng)增益控制(AGC)芯片顯得尤為重要，是地面接收系統(tǒng)靈敏度、動(dòng)態(tài)范圍、可靠性及誤比特率性能的關(guān)鍵保證。 針對(duì)北斗衛(wèi)星導(dǎo)航定位接收系統(tǒng)的應(yīng)用，本文研究設(shè)計(jì)了一款具有大動(dòng)態(tài)范圍、高線性度的自動(dòng)增益控制芯片，芯片包括可變?cè)鲆娣糯笃?VGA)、電荷泵(CP)及模數(shù)轉(zhuǎn)換器(ADC)等模塊，可以實(shí)現(xiàn)對(duì)下變頻后中頻信號(hào)的增益自動(dòng)控制放大。針對(duì)衛(wèi)星信號(hào)功率微弱、動(dòng)態(tài)范圍大的特點(diǎn)，本文提出了一種新型的具有跨導(dǎo)提高(gm-boosting)技術(shù)的可變?cè)鲆娣糯箅娐方Y(jié)構(gòu)，使電路的指數(shù)增益(dB-linear)范圍和三階交調(diào)性能得到顯著改善；提出了一種改進(jìn)型的電荷泵，通過(guò)額外的充放電電流能使電荷泵的輸出電壓快速穩(wěn)定至可變?cè)鲆娣糯笃魉苷{(diào)節(jié)的范圍，有效縮短了AGC芯片的穩(wěn)定時(shí)間。 本文采用Global Foundry180nm CMOS工藝對(duì)提出的大動(dòng)態(tài)自動(dòng)增益控制芯片進(jìn)行了前端電路設(shè)計(jì)、后端物理版圖的設(shè)計(jì)與驗(yàn)證。芯片采用1.8V供電，后仿真結(jié)果顯示：芯片中的VGA增益范圍為-27dB~75dB，dB-linear范圍達(dá)到75dB(誤差±1dB)；AGC芯片的最大線性放大帶寬為25MHz，輸入三階交調(diào)點(diǎn)達(dá)到-38dBm，穩(wěn)定時(shí)間小于130s，消耗電流1.9mA，可以滿足高端北斗衛(wèi)星地面導(dǎo)航系統(tǒng)對(duì)接收靈敏度及動(dòng)態(tài)范圍冗余度的苛刻要求。
[Abstract]:Beidou satellite navigation and positioning system is a global satellite positioning and communication navigation system developed independently in China. It has a wide application space in military operations and civil life such as traffic navigation, timing, geological exploration, geographical mapping and so on. Satellite navigation and positioning data pass through a long distance of wireless channels, electromagnetic interference is complex, and because of the spread spectrum technology, the radiation power spectrum of Beidou radio frequency signal is extremely low, which is submerged under the noise base. Therefore, the requirements of the receiver sensitivity and the dynamic range performance of automatic gain regulation for the Beidou ground RF receiver front end are put forward. In order to make the Beidou satellite ground navigation and positioning system adapt to all kinds of harsh and complex ground operation environment, the automatic gain control (AGC) chip used in RF front-end circuit is especially important, which is the sensitivity of the ground receiving system. Key guarantees for dynamic range, reliability and bit error rate performance. Aiming at the application of Beidou satellite navigation and position receiving system, this paper designs an automatic gain control chip with large dynamic range and high linearity. The chip includes variable gain amplifier (VGA),). Charge pump (CP) and analog-to-digital converter (ADC) modules can automatically control and amplify the gain of downconversion if signal. Aiming at the characteristics of weak power and large dynamic range of satellite signal, a new type of variable gain amplifier with transconductance enhancement (gm-boosting) technology is proposed in this paper. The exponential gain (dB-linear) range and the third-order intermodulation performance of the circuit are improved significantly. An improved charge pump is proposed. The output voltage of the charge pump can be rapidly stabilized to the range that the variable gain amplifier can adjust by the extra charge and discharge current, and the stable time of the AGC chip can be effectively shortened. In this paper, Global Foundry180nm CMOS technology is used to design the front circuit of the proposed large dynamic automatic gain control chip, and the physical layout of the back end is designed and verified. The chip uses 1.8 V power supply, and the post-simulation results show that the gain range of VGA in the chip is -27dBU 75dBB-linear 75dB (error 鹵1dB); The maximum linear amplification bandwidth of the AGC chip is 25MHz, the input third-order intermodulation point reaches -38dBm, the stabilization time is less than 130s, and the current consumption is 1.9 Ma. It can meet the strict requirements of receiving sensitivity and dynamic range redundancy of high-end Beidou satellite ground navigation system.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TN965.5

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相關(guān)博士學(xué)位論文 前1條

1 李兵;多模兼容衛(wèi)星導(dǎo)航接收機(jī)射頻前端芯片關(guān)鍵技術(shù)研究[D];西安電子科技大學(xué);2011年

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