Design and performance analysis of cylindrical surrounding double-gate MOSFET for RF switch

In this paper, we have analyzed the design parameters of Cylindrical Surrounding Double-Gate (CSDG) MOSFETs as an RF switch for the advanced wireless telecommunication systems. The proposed CSDG RF MOSFET is operated at the microwave regime of the spectrum. We emphasize on the basics of the circuit elements such as drain current, threshold voltage, resonant frequency, resistances at switch ON condition, capacitances, energy stored, cross talk and switching speed required for the integrated circuit of the radio frequency sub-system of the CSDG RF CMOS device and the physical significance of these basic circuit elements is also discussed. We observed that the total capacitance between the source to drain for the proposed CSDG MOSFET is more compared to the Cylindrical Surrounding Single-Gate (CSSG) MOSFET due to the greater drain current passing area of the CSDG MOSFET, which reveals that the isolation is better in the CSDG MOSFET compared to that of the simple double-gate MOSFET and single-gate MOSFET. We analyzed that the CSDG MOSFET stores more energy (1.4 times) as compared to the CSSG MOSFET. Therefore, the CSDG MOSFET has more stored energy. The ON-resistance of CSDG MOSFET is half than that of the double-gate MOSFET and single-gate MOSFET, which reveals that the current flow from source to drain in CSDG MOSFET is better than the double-gate MOSFET and single-gate MOSFET.     

基于无源超高频射频识别标签的湿度传感器设计

针对无源超高频射频识别传感器标签大规模运用的需求,采用中芯国际0.35μm互补金属氧化物半导体(CMOS)工艺设计并制造了一种低成本、低功耗的湿度传感器.湿度传感器单元采用聚酰亚胺作为感湿材料,利用顶层金属层制作叉指结构电极,制造过程与标准CMOS制造工序兼容,无需任何后处理工艺.接口电路部分基于锁相环原理,采用全数字电容.数字直接转换结构,能够工作在接近工艺阈值电压下.后期测试结果显示,该湿度传感器在常温下灵敏度为36.5 fF%RH,最大回滞偏差为7%,响应时间为20 ms,0.6 V电源电压下消耗2.1μW功率.     

压电陶瓷性能波动对加速度传感器性能影响

根据压缩式加速度传感器的结构建立其有限元模型;并利用ANSYS10.0软件对加速度度传感器进行仿真计算,分析了压电陶瓷材料的压电常数和弹性柔顺系数对灵敏度和幅频特性的影响;该计算结果为压电陶瓷材料的选择及陶瓷材料制备工艺的改进提供了参考依据.     

基于时分外差法检测的非对称薄壁壳型光纤一维地震波检波器

研制了基于时分外差法检测的非对称薄壁壳型光纤一维地震波检波器, 该检波器易于扩展为三轴分立式地震波检波器, 具有检测动态范围大, 易于构成大规模时分复用传感网络的优点。建立了非对称地震波检波器的理论模型, 分析了各结构参数对其灵敏度的影响; 搭建了基于光学同步参考信号的时分外差法测试系统, 进行了外差系统的稳定性测试, 测量了地震波检波器的频响曲线, 结果表明外差系统测量信号波动小于0.1dB; 工作频段20~800Hz内加速度平均灵敏度为28.5dB re rad/g, 与理论仿真结果基本吻合。     

正交双加速度计两种安装位置在重力场中的标定方法

为了提高加速度计在1g重力场中的标定精度,分度头的角位置误差应非常小或将它有效地分离。提出了一种将正交双加速度计在分度头上,进行两种安装位置组合测试的方法。推导了加速度计误差模型系数的标定误差与分度头角位置误差成分的关系,设计了两种安装位置组合测试方法,从加速度计的输出中可分离分度头的角位置误差,提高加速度计误差模型系数的辨识精度,对试验数据进行误差分析后验证了该方法的正确性。     

一种压阻式单片集成MEMS三轴加速度传感器

An integrated MEMS accelerometer has been designed and fabricated.The device,which is based on the piezoresistive effect,accomplishes the detection of three components of acceleration by using piezoresistors to compose three Wheatstone bridges that are sensitive to the only given orientation.The fabrication of the accelerometer is described,and the theory behind its operation developed.Experimental results on sensitivity,crossaxis-coupling degree,and linearity are presented.The sensitivity of X,Y and Z were 5.49 mV/g,5.12 mV/g and 4.82 mV/g,respectively;the nonlinearity of X,Y and Z were 0.01%,0.04% and 0.01%,respectively;the crossaxis-coupling factor of X axis to Y axis and Z axis are 0.119% and 2.26%;the cross-axis-coupling factor of Y axis to X axis and Z axis are 0.157%and 4.12%;the cross-axis-coupling factor of Z axis to X axis and Y axis are 0.511% and 0.938%.The measured performance indexes attain accurate vector-detection in practical applications, and even at a navigation level.In conclusion,the accelerometer is a highly integrated sensor.     

97dB动态范围、带温度补偿的MEMS电容传感器读出电路

This paper presents a charge-sensitive-amplifier(CSA)based readout circuit for capacitive microelectro-mechanical-system(MEMS)sensors.A continuous-time(CT)readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits.An operational trans-conductance amplifier(OTA)structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal.An analog temperature compensation method is proposed,which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity.The chip is designed and implemented in a 0.35 m CMOS process and is 2.1 2.1 mm2in area.The measurement shows that the readout circuitachieves0.9aF/√Hz capacitive resolution,97dBd ynamic range in 100Hz signal bandwidth,and 0.8mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.     

Highly configurable capacitive interface circuit for tri‐axial MEMS microaccelerometer

A highly configurable capacitive interface circuit with on‐chip calibration capability for tri‐axial microaccelerometer is presented. The capacitive interface circuit is designed to be programmable, and can reduce the output errors due to the parasitic capacitance variations and process variations. The capacitive sensing chain adopts the chopper stabilisation, and includes the front‐end charge amplifier with three 10‐bit programmable capacitor arrays, 9‐bit digital‐to‐analogue converter and 10‐bit programmable gain amplifier. The calibration coefficients are stored to the on‐chip erasable programmable read only memory. The outputs from the three‐channel capacitive sensing chain are converted to digital signal by the integrated 14‐bit algorithmic analogue‐to‐digital converter. After calibrating the 48 samples, all the samples meet the desired specification range. Before the calibration, the errors of the average values of the output offset and gain were +47.1% and ?85.9%, respectively. After the calibration, however, the errors of the average values of the output offset and gain are reduced to be 0.3% and 0.5%, respectively. The resolutions for x/y‐axis and z‐axis are measured to be 326 and 728?µg, respectively.     

基于喇曼-奈斯衍射的微光机电加速度计理论分析和原理验证

本文设计并模拟了了一种新型的基于喇曼-奈斯衍射的微光机电（MOEMS）加速度计。该加速度计将通过MEMS技术制造,并具有与已见报导的MOEMS加速度计完全不同的敏感原理。本文详细讨论了该新型加速度计的基础理论与原理;建立了弯曲板波延迟线振荡器的3D有限元模型,进行了谐响应分析和瞬态分析,得到器件工作频率在40MHz左右;最后建立了该微型加速度计的宏模型,对该器件的可行性进行了论证。该新型加速度计具有灵敏度高、抗辐射等优点,具有很大的应用前景。     

HIRFL-CSR电子冷却束流位置测量系统

高效率的电子冷却过程, 要求电子束与离子束位置平行且重叠。 为了同时测量电子束与离子束的位置, 在HIRFL CSR电子冷却装置上研发了以容性圆筒形极板为感应电极的束流位置探测系统。 系统测量束流通过探针时产生的脉冲感应信号, 并进行傅里叶变换得到频谱信号, 分析4个不同电极上频谱信号强度获取束流的位置信息。 测量结果表明, 该束流位置探测系统测量准确, 为定量研究储存环离子累积和电子冷却过程与两种束流相对位置及角度的依赖关系提供了条件。 The efficient electron cooling requires that the ion beam and electron beam are parallel and overlapped. In order to measure the positions of ion beam and electron beam simultaneously, a beam position monitor system is developed for the HIRFL-CSR electron cooler device, which probe consists of four capacitive cylinder linear cut poles. One can get the both beam positions from the picking up signals of four poles by using Fourier transform(FFT) method. The measurement results show that the beam position monitor system is accurate. This system is suitable for investigating the relation between electron cooling processing and the angle of ion beam and electron beam.