Low-noise,low-power-consumption seafloor vector magnetometer

The seafloor vector magnetometer is an effective tool for marine geomagnetic surveys and seafloor magnetotelluric(MT)detection.However,the noise,power consumption,cost,and volume characteristics of existing seafloor vector magnetometers are insufficient for practical use.Therefore,a low-noise,low-power-consumption seafloor vector magnetometer that can be used for data acquisition of deep-ocean geomagnetic vector components is developed and presented.A seafloor vector magnetometer mainly consists of a fluxgate sensor,data acquisition module,acoustic release module,glass sphere,frame,burn-wire release,and anchor.A new low-noise data acquisition module and a fluxgate sensor greatly reduce power consumption.Furthermore,compact size is achieved by integrating an acoustic telemetry module and replacing the acoustic release with an external burn-wire release.The new design and magnetometer characteristics reduce the volume of the instrument and the cost of hardware considerably,thereby improving the integrity and deployment efficiency of the equipment.Theoretically,it can operate for 90 days underwater at a maximum depth of 6000 m.The seafloor vector magnetometer was tested in the South China Sea and the Philippine Sea and obtained high-quality geomagnetic data.The deep-water environment facilitates magnetic field data measurements,and the magnetometer has an approximate noise level of 10 pT/rt(Hz)@1 Hz,a peak-to-peak value error of 0.2 nT,and approximate power consumption of 200 mW.The fluxgate sensor can measure the magnetic field in the lower frequency band and realize geomagnetic field measurements over prolonged periods.

Low power consumption 4-channel variable optical attenuator array based on planar lightwave circuit technique

The power consumption of a variable optical attenuator（VOA） array based on a silica planar lightwave circuit was investigated. The thermal field profile of the device was optimized using the finite-element analysis. The simulation results showed that the power consumption reduces as the depth of the heat-insulating grooves is deeper, the up-cladding is thinner,the down-cladding is thicker, and the width of the cladding ridge is narrower. The materials component and thickness of the electrodes were also optimized to guarantee the driving voltage under 5 V. The power consumption was successfully reduced to as low as 155 mW at an attenuation of 30 dB in the experiment.

Low Power Consumption Distributed-Feedback Quantum Cascade Lasers Operating in Continuous-Wave Mode above 90℃ at λ～7.2μm

We report on the design and fabrication of λ-7.2μm distributed feedback quantum cascade lasers lot very high temperature cw operation and low electrical power consumption. The cw operation is reported above 90℃. For a 2-mm-long and 10-μm-wide laser coated with high-reflectivity on the rear facet, more than 170mW of output power is obtained at 20℃ with a threshold power consumption of 2.4 W, corresponding to 30mW with a threshold power consumption of 3.9 W at 90℃. Robust single-mode emission with a side-mode suppression ratio above 25 dB is continuously tunable by the heat sink temperature or injection current.

A hybrid storage technology for low power consumption and high I/O performance in an IPTV set-top box

A new method of prefetching data blocks from the NVCache to the page cache in main memory and cascading prefetching n-blocks from a hard disk to the NVCache together was proposed to reduce the spin-up frequency of a hybrid hard disk drive and thus enhance I/O performance.The proposed method consists of three steps:1) Analyzing the pattern of read requests in block units;2) Determining the number of blocks prefetched to the NVCache;3) Replacing blocks in the NVCache according to the block replacement policy.The proposed method can reduce the latency time of a hybrid hard disk and optimize the power consumption of an IPTV set-top box.Experimental results show that the proposed method provides better average response time compared to an existing adaptive multistream prefetching(AMP) method by 25.17%.It also reduces by 20.83% the average power consumption over that of the existing external caching in energy saving storage system(EXCES) method.

Study of a GaAs MESFET Model with Ultra-Low Power Consumption

A model of enhancement mode GaAs MESFET (EFET) for low power consumption and low noise applications has been obtained by using a small signal equivalent circuit whose component values are derived from the physical parameters and the bias condition. The dependence of the RF performance and DC power consumption on physical, material and technological parameters of EFET is also studied. The optimum range of the physical parameters is given which is useful for the design of active device of ultra low power consumption MMIC.

A vector inserting TPG for BIST design with low peak power consumption

A test pattern generator （TPG） which can highly reduce the peak power consumption during built-in self-test （BIST） application is proposed. The proposed TPG, called LPpe-TPG, consists of a linear feedback shift register （LFSR） and some control circuits. A procedure is presented firstly to make compare vectors between pseudorandom test patterns by adding some circuits to the original LFSR and secondly to insert some vectors between two successive pseudorandom test patterns according to the ordinal selection of every two bits of the compare vector. Then the changes between any successive test patterns of the test set generated by the LPpe-TPG are not more than twice. This leads to a decrease of the weighted switching activity （WSA） of the circuit under test （CUT） and therefore a reduction of the power consumption. Experimental results based on some ISCAS＇ 85 benchmark circuits show that the peak power consumption has been reduced by 25.25% to 64.46%. Also, the effectiveness of our approach to reduce the total and average power consumption is kept, without losing stuck-at fault coverage.

一种基于NB-IoT的智能井盖监测系统设计

针对城市井盖保有量大、安全事故频发、人工巡检困难、管理组织混乱等问题,提出一种基于窄带物联网(NB-IoT)技术的窨井盖自动监测系统。该系统以STM32作为主控模块,包含倾角、水位等传感器,实现对井盖状态以及井内重点数据的采集,配合云端服务器和客户端完成井盖数据远程可视化显示。结果表明,所提系统可以实现故障井盖自动报警、精确定位,降低人工巡检的难度,让城市井盖管理更加智能化,让故障检修更加便捷化,提高城市管理的智能化水平。

基于NB-IoT的智慧健康监测系统设计

人口老龄化导致慢性非传染性的患病率会越来越高,智慧健康养老成为国家应对老龄化的战略目标。针对我国目前的人口结构现状,提出一种基于窄带物联网技术(NB-IoT)的智慧健康监测系统。该系统结合NB-IoT技术、传感器技和软件技术,系统主要包括可穿戴数据采集终端、云服务平台、远程监测平台等3部分。数据采集终端以STM32作为主控制器,实现对用户生理信息的采集,通过NB-IoT网络传输到云平台上,通过远程监测平台实现健康的远程监测,对健康问题进行预警。实验结果表明:系统可以实时采集老年人的生理信息(血压、血氧、心率)、运动轨迹以及定位信息,对老年人进行实时全方位健康监控,提前预防并降低慢性疾病发病率、减小死亡率、延长寿命。

基于NB-IoT的地下管廊环境监测系统设计

城市地下管廊内布设了大量的管线,如燃气管道、网络通讯线路、电力线路等,由于地下环境复杂多变,存在着气体泄漏、爆炸、火灾等安全风险。针对这些问题,提出一种基于窄带物联网技术(Narrow Band Internet of Things,NB-IoT)的地下管廊环境监测系统。该系统采用先进的传感器技术、NB-IoT技术、软件技术,系统主要分为数据采集模块、物联网云平台、远程监测系统三部分。数据采集模块以STM32作为主控单元连接各个传感器,采集温度、湿度、水位、可燃气体等数据,经过处理后利用NB-IoT网络上传到物联网云平台,远程监测系统调用物联网云平台的数据接口进行远程显示与预警。实验结果表明,系统在降低系统总体功耗的同时,能够实时、稳定地进行地下管廊环境监测,提前预防可能存在的风险。

用于Pipelined-SAR模数转换芯片中的高精度比较器设计

设计了一款可用于18 bit、2 Ms/s的流水线型逐次逼近型模数转换器(Pipelined-SAR ADC)的高精度比较器,该比较器的结构为三级预放大器+锁存器(latch),同时采用了一种失调电压消除技术,有效减小了比较器的失调电压。在TSMC 0.18μm的工艺下,使用Spectre对比较器进行仿真,结果表明,该比较器在1.8 mW的功耗下,输入失调电压标准差为131μV,噪声电压为15μV,满足高精度和低功耗的要求。

A low-power Rijndael S-Box based on pass transmission gate and composite field arithmetic

Using composite field arithmetic in Galois field can result in the compact Rijndael S-Box. However, the power con- sumption of this solution is too large to be used in resource-limited embedded systems. A full-custom hardware implementation of composite field S-Box is proposed for these targeted domains in this paper. The minimization of power consumption is implemented by optimizing the architecture of the composite field S-Box and using the pass transmission gate (PTG) to realize the logic functions of S-Box. Power simulations were performed using the netlist extracted from the layout. HSPICE simulation results indicated that the proposed S-Box achieves low power consumption of about 130 μW at 10 MHz using 0.25 μm/2.5 V technology, while the consumptions of the positive polarity reed-muller (PPRM) based S-Box and composite field S-Box based on the conventional CMOS logic style are about 240 μW and 420 μW, respectively. The simulations also showed that the presented S-Box obtains better low-voltage operating property, which is clearly relevant for applications like sensor nodes, smart cards and radio frequency identification (RFID) tags.

高精度Sigma-Delta调制器设计

近年来,在过采样型模数转换器中,Sigma-Delta模数转换器以其较高的精度成为模数转换器的热点。介绍了一种高精度低功耗的Sigma-Delta调制器设计。使用Matlab工具完成三阶一位量化CIFF结构的系统仿真,在系统级仿真结果的指导下,积分器采用分级结构优化电路结构。积分器电路模块设计采用了全差分式开关电容电路,抑制了谐波失真对输出精度的影响。仿真结果显示:5 S/s挡位时,对应的PVT组合中最低有效位数为17.67 bits;2 kS/s挡位时,对应的PVT组合中最低有效位数为15.89 bits,整个调制器功耗低于3 mW。通过改进调制器整体架构、积分器结构和量化器的设计方法,降低了调制器功耗,提升了调制器精度。

GIS缺陷检测用低功耗智能无线振动加速度-声发射融合传感器

针对气体绝缘组合电器(GIS)机械和绝缘缺陷的同时同地感知,本文提出一种低功耗智能无线振动加速度-声发射融合传感器。进行了传感器融合结构设计和仿真验证,使用蓝牙低功耗(BLE)实现传感器与客户端通信。首次将伪随机M序列应用于压电传感器的阻抗响应自校准,单次校准仅需数毫秒和数毫瓦。测试结果表明,传感器100 Hz~2 kHz内平均振动灵敏度为511 mV/g, 20~100 kHz内超声灵敏度稳定在70~90 dB之间,相对不确定度小于2%;工作距离小于8 m时,数据传输速率在1 Mbps以上。在设置金属颗粒缺陷的实际GIS设备上开展机械振动-局部放电联合试验,结果表明传感器可实现设备机械振动和超声波信号的同时同地测量,为电力设备运行状态的分布式检测提供了新型有效的方法和手段。

Real-Time Tunable Gas Sensing Platform Based on SnO_(2) Nanoparticles Activated by Blue Micro-Light-Emitting Diodes

Micro-light-emitting diodes(μLEDs)have gained significant interest as an activation source for gas sensors owing to their advantages,including room temperature operation and low power consumption.However,despite these benefits,challenges still exist such as a limited range of detectable gases and slow response.In this study,we present a blueμLED-integrated light-activated gas sensor array based on SnO_(2)nanoparticles(NPs)that exhibit excellent sensitivity,tunable selectivity,and rapid detection with micro-watt level power consumption.The optimal power forμLED is observed at the highest gas response,supported by finite-difference time-domain simulation.Additionally,we first report the visible light-activated selective detection of reducing gases using noble metal-decorated SnO_(2)NPs.The noble metals induce catalytic interaction with reducing gases,clearly distinguishing NH3,H2,and C2H5OH.Real-time gas monitoring based on a fully hardwareimplemented light-activated sensing array was demonstrated,opening up new avenues for advancements in light-activated electronic nose technologies.

A Study of Efficient Power Consumption Wireless Communication Techniques/ Modules for Internet of Things (IoT) Applications

A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT applications by introducing a comparative between different low power wireless communication techniques such as ZigBee, Low Power Wi-Fi, 6LowPAN, LPWA and their modules to conserve power and longing the life for the IoT network sensors. The approach of the study is in term of protocol used and the particular module that achieve that protocol. The candidate protocols are classified according to the range of connectivity between sensor nodes. For short ranges connectivity the candidate protocols are ZigBee, 6LoWPAN and low power Wi-Fi. For long connectivity the candidate is LoRaWAN protocol. The results of the study demonstrate that the choice of module for each protocol plays a vital role in battery life due to the difference of power consumption for each module/protocol. So, the evaluation of protocols with each other depends on the module used.

Resistive switching characteristic and uniformity of low-power HfO_x-based resistive random access memory with the BN insertion layer

In this letter,the Ta/HfO/BN/TiN resistive switching devices are fabricated and they exhibit low power consumption and high uniformity each.The reset current is reduced for the HfO/BN bilayer device compared with that for the Ta/HfO/TiN structure.Furthermore,the reset current decreases with increasing BN thickness.The HfOlayer is a dominating switching layer,while the low-permittivity and high-resistivity BN layer acts as a barrier of electrons injection into TiN electrode.The current conduction mechanism of low resistance state in the HfO/BN bilayer device is space-chargelimited current(SCLC),while it is Ohmic conduction in the HfOdevice.

Low-Power Design of Ethernet Data Transmission

For the reliability and power consumption issues of Ethernet data transmission based on the field programmable gate array （FPGA）, a low-power consumption design method is proposed, which is suitable for FPGA implementation. To reduce the dynamic power consumption of integrated circuit （IC） design, the proposed method adopts the dynamic control of the clock frequency. For most of the time, when the port is in the idle state or lower-rate state, users can reduce or even turn off the reading clock frequency and reduce the clock flip frequency in order to reduce the dynamic power consumption. When the receiving rate is high, the reading clock frequency will be improved timely to ensure that no data will lost. Simulated and verified by Modelsim, the proposed method can dynamically control the clock frequency, including the dynamic switching of high-speed and low-speed clock flip rates, or stop of the clock flip.

低功耗Wi-Fi技术在便携式设备电源故障诊断中的应用

低功耗Wi-Fi技术作为一种新兴的无线通信技术,用于实时监测和诊断电源故障,保障便携式设备的稳定运行。文章详细描述电池管理模块、低功耗控制模块、故障预测预警模块以及故障分析定位模块的具体实现和工作流程。实验结果表明,低功耗Wi-Fi技术可以显著提升故障诊断的准确性和实时性,降低系统能耗,延长电池续航时间,并且在系统运行时间上表现优异。

基于NB-IoT的校园智能垃圾桶系统的研究--以江西师范高等专科学校为例

文章设计了一种低功耗多功能的智能垃圾桶,将STM32L431RC作为主控芯片、将NB-IoT作为通信模块,通过传感器模块采集垃圾桶的满溢情况并监测垃圾桶的状态。其中,垃圾桶的状态数据可经NB-IoT发送至云平台,云平台收到数据后将通知工作人员及时进行垃圾清理。相较于传统垃圾桶,该智能垃圾桶具有功耗低的特点,可大量部署并通过物联网实现远程管理和控制。

基于eDRX模式的NB-IoT阀控水表的研究

当前市场上NB-IoT电池供电阀控水表使用PSM模式,关阀期间通过增加上报频率,尽可能降低阀控响应延时。但上报频率的增加会造成功耗的显著增加,功耗和阀控响应延时两个变量相互制约,为满足电池使用寿命,一般阀控期间上报频率1小时,阀控响应实时性低,时延达1小时。针对该问题,提出一种在不增加功耗的前提下,缩短阀控响应时延的方法。该方法通过基于NB-IoT技术的eDRX模式,采用网络快速释放方法并优化通讯交互逻辑,实现缩短阀控响应时延并降低整机功耗。测试结果显示,与现有PSM模式的阀控水表相比,电池使用年限正常,阀控响应时延由1小时降低至40.96秒,对阀控水表产品未来的发展具有一定的参考意义。