Analysis and design of power efficient semi-passive RFID tag

The analysis and design of a semi-passive radio frequency identification(RFID) tag is presented.By studying the power transmission link of the backscatter RFID system and exploiting a power conversion efficiency model for a multi-stage AC-DC charge pump,the calculation method for semi-passive tag's read range is proposed.According to different read range limitation factors,an intuitive way to define the specifications of tag's power budget and backscatter modulation index is given.A test chip is implemen...     

A 900 MHz,21 dBm CMOS linear power amplifier with 35% PAE for RFID readers

A two-stage differential linear power amplifier(PA) fabricated by 0.18μm CMOS technology is presented. An output matching and harmonic termination network is exploited to enhance the output power,efficiency and harmonic performance.Measurements show that the designed PA reaches a saturated power of 21.1 dBm and the peak power added efficiency(PAE) is 35.4%,the power gain is 23.3 dB from a power supply of 1.8 V and the harmonics are well controlled.The total area with ESD protected PAD is 1.2×0.55 mm~2.Sy...     

一种适用于射频电子标签的超低功耗嵌入式EEPROM

采用Chartered 0.35μm EEPROM工艺设计并实现了一个适用于无源射频电子标签的256位超低功耗EEPROM存储器.芯片实现了块编程和擦写功能,并通过优化敏感放大器和控制逻辑的结构,实现了读存储器时间和功耗的最优化.最后给出了芯片在编程/擦写/读操作情况下的功耗测试结果.在电源电压为1.8V,数据率为640kHz时,EEPROM编程/擦写的平均功耗约为68μA,读操作平均功耗约为0.6μA.     

基于组件技术的地下水资源管理系统开发

组件式的理信息系统(ComGIS)是当前新一代地理信息系统发展方向之一、该文阐述了组件式GIS基本概念,并根据“长江三角洲(南部)地区地下水资源管理系统”的开发,在分析本管理系统需求的基础上,从数据管理、模型建立、专题制图、三维可视化等多方面讨论了组件式软件技术在GIS二次开发中的应用。     

A 5 GHz CMOS frequency synthesizer with novel phase-switching prescaler and high-Q LC-VCO

A phase-locked loop(PLL) frequency synthesizer with a novel phase-switching prescaler and a high-Q LC voltage controlled oscillator(VCO) is presented.The phase-switching prescaler with a novel modulus control mechanism is much more robust on process variations.The Q factor of the inductor,I-MOS capacitors and varactors in the VCO are optimized.The proposed frequency synthesizer was fabricated by SMIC 0.13μm 1P8M MMRF CMOS technology with a chip area of 1150×2500μm~2.When locking at 5 GHz,the current consumption is 15 mA from a supply voltage of 1.2 V and the measured phase noise at a 1 MHz offset is -122.45 dBc/Hz.     

低温液化石油气和液化天然气储库及相关岩石力学研究进展

首先介绍低温液化石油气(LPG)和低温液化天然气(LNG)地下储库的建库技术,对目前低温LPG和低温LNG地下储库工程的现场试验和理论分析两方面进行总结;从中引出相关的冻岩力学问题,从4个方面综述目前研究现状：(1)岩石在低温下或冻融循环下的物理性状研究;(2)低温冻结或冻融循环对裂隙的作用研究;(3)水分迁移研究;(4)低温冻结岩体中三场耦合研究。由于实验室岩块和现场岩体的差异,探讨冰冻作用对岩块和岩体的差异及作用机制,对水分迁移及冻结岩体中温度场研究进行思考,最后对LPG,LNG地下储库工程的建设及稳定进行讨论。     

65nm工艺下20Gb/s无电感限幅放大器设计与分析

本文设计了一款能工作在20Gb/s速率下的无电感限幅放大器。限幅放大器包括三各部分：带直流失调消除的输入匹配级,增益级和输出驱动级。本设计采用交叉负反馈技术,使得放大器在获得高带宽的同时拥有较为平坦的频率响应。直流失调消除环路中增加了误差放大器来保证直流失调消除效果。放大器在65纳米工艺下成功流片,芯片面积为0.45 × 0.25平方毫米（不包括PAD）,测试结果显示放大器的差分增益为37dB,带宽为16.5GHz,在高达26.5GHz的频率内Sdd11和Sdd22分别小于-16dB和-9dB。除了驱动级,整个放大器在1.2V的电源电压下消耗50mA的电流。     

石墨烯添加剂对铅酸电池性能影响的研究

将石墨烯作为添加剂添加到铅酸蓄电池负极活性物质中,探究其对铅酸蓄电池性能的影响。无论是添加水性浆料状还是粉末状石墨烯,电池的容量都没有明显增加,并且随着石墨烯含量增加,电池容量降低,电池低温性能变差,但是充电接受性能提高。水性浆料状石墨烯含量为 1 % 的样品电池充电接受能力提升近 41 %。交流阻抗测试显示,加入水性浆料状石墨烯使蓄电池阻抗变大,但石墨烯与炭黑混合使用时,阻抗最小。     

A low-noise widely tunable Gm-C filter with frequency calibration

A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 μm CMOS process. It exhibits a wide programmable bandwidth from 322.5 kHz to 20 MHz. Measured results show that the filter has low input referred noise of 5.9 nV/√Hz and high out-of-band ⅡP3 of 16.2 dBm. It consumes 4.2 and 9.5 mW from a 1 V power supply at its lowest and highest cut-off frequencies respectively.