A Novel High-Speed Multiplexing IC Based on Resonant Tunneling Diodes

A new multiplexing IC based on the resonant tunneling diode (RTD) is proposed. The unique negative differential resistance characteristics arising from quantum effects of the RTD enable us to develop a new functional low-power digital circuit. The proposed multiplexing IC consists of two current-mode-logic monostable-bistable transition logic elements (CML-MOBILEs) based on the RTD and a low-power selector circuit block. The proposed circuit has been fabricated by using an InP RTD/ heterojunction bipolar transistor monolithic microwave integrated circuit technology. The multiplexing operation of the fabricated quantum effect IC has been confirmed up to 45 Gb/s for the first time as a monolithic technology based on the quantum effect devices. The dc power consumption is only 23 mW, which is found to be one-fourth of the current state-of-the-art conventional transistor-based multiplexing IC.     

基于共振光隧穿效应的角加速度传感器设计

阐述了一种基于共振光隧穿效应的角加速度传感器的设计方法,分析了其传感特性,并以共振光隧穿理论为基础,利用Mathematica软件进行了仿真分析。该加速度传感器的品质因数可以达到1.96×10⁸,远高于经典F-P腔的品质因数8.183×104。灵敏度可以达到0.1°/nm,     

基于矢量水听器的南海海洋背景噪声测试

矢量声压振速联合处理建立在信号的声压和振速相位基础上,海洋环境边界影响将改变矢量声场声压振速的幅度和相位特性．首先根据南海环境条件结合水下目标辐射噪声测量,采用声场矢量简正波理论估算海面非相干偶极子噪声和水下点声源矢量强度随深度的变化,然后设计了可用于深海海域噪声测量的矢量水听器测试系统,获取了南海海域典型深度上的背景噪声矢量强度并进行了特性分析．结果表明：深海背景噪声谱级在500Hz以下基本上不随深度变化,在500Hz～3kHz频段浅深度背景噪声谱级略高于较深深度的背景噪声;振速垂直分量的背景噪声要小于声压和振速水平分量的噪声谱级．     

纤毛式MEMS矢量水声传感器的仿生组装

提出了一种纤毛式微机电系统（MEMS）矢量水声传感器的仿生组装技术.期望结合MEMS工艺和仿生组装工艺技术,解决复杂结构的仿生制造问题.文中简单介绍了仿生学理论以及定向探测机理.采用MEMS基硅微机械加工技术完成了传感器微结构的加工.通过模仿鱼类侧线器官神经丘感觉器的仿生结构,完成了传感器仿生微结构的组装,制作出纤毛式硅微仿生矢量水声传感器的模型样机.最后,完成了传感器的校准测试.测试结果表明,该水声传感器不但体积小、质量轻、结构简单,而且具有“8”字型的指向特性.该水声传感器的声压灵敏度为-197.7 dB（0 dB=1 V/μPa）.     

矢量水听器校准装置的不确定度评定

本文介绍了矢量水听器校准装置的工作原理,系统组成及校准矢量水听器灵敏度和指向性的工作流程,并对该装置的不确定度进行分析评定。     

基于GaAs/AlAs腐蚀自停止的新型水听器工艺

针对感应耦合等离子（ICP）刻蚀气室气体分布不均匀性所导致的被刻蚀台面中间厚、边缘薄及干法刻蚀后残余应力大等缺点,进行了GaAs／AlAs的选择性湿法腐蚀工艺研究．腐蚀液为50％一水柠檬酸（C6H8O7·H2O）溶液与30％双氧水（H2O2）的混合物,当二者体积比为3：1时,GaAs／AlAs的选择比达到79以上．用原子力显微镜（AFM）和扫描电镜（SEM）对腐蚀后的试验片测试后发现,该体积比腐蚀液腐蚀的试验片具有表面粗糙度低、刻蚀各向异性好、选择比高等优点,能够满足传感器加工的需要;结合试验结果,设计了一种待加工梁厚3μm的外延材料结构,并对传感器的加工工艺进行了优化;最后,采用ANSYS对所设计的结构进行了仿真分析,仿真结果表明,该结构具有可行性,可实现水平面内的声学探测．     

新型三轴压阻式硅微加速度计的研究

微惯性系统以及其他高精密场合往往需要高精度三轴加速度计来检测三个垂直方向加速度矢量。针对类似需求,介绍了一种四边八梁结构式三轴压阻式硅微加速度计,利用硅衬底上单一质量块和惠斯通半桥结构可同时实现三个轴向上的加速度高精度测量。另外设计了微加速度计在高过载环境下的硅一玻璃防护结构和体硅加工工艺,并通过ANSYS仿真和试验验证了加速度计结构的合理性,还对微加速度计相关性能进行了测试,测试结果表明,该微加速度计具有较高的测量精度和较好的线性度,满足设计要求。     

基于集合经验模态分解的MEMS矢量水听器联合去噪算法

针对MEMS矢量水听器的噪声去除问题,将集合经验模态分解(EEMD)、小波阈值去噪(WT)和奇异谱分析(SSA)相结合,提出了一种联合EEMD-WT-SSA去噪算法.该算法首先将含噪信号分解为一系列固有模态函数(IMF),然后,用连续均方误差准则(CMSE)对高频和低频进行区分,对高频信号进行小波阈值去噪,再和低频信号...     

MEMS仿生矢量水听器优化设计

针对纤毛式MEMS仿生单矢量水听器灵敏度偏低、频响曲线起伏较大的缺陷,对该结构水听器进行了优化设计.通过理论分析和仿真计算,从两方面进行了优化,一是纤毛材料的选择,选用光纤替代塑料柱体;二是设计了一种"半油半酯"新型封装结构.最后在国防水声一级计量站对该封装水听器进行了相应的校准测试.测试结果表明,该水听器性能较之前有了明显提高,灵敏度达到-165 dB(包括前置放大26 dB),频响范围为20 Hz～2 kHz(±4 dB),具有良好的"8"字型指向性.     

平面型共振隧穿二极管的制作

采用离子注入方法制作了一种新型平面共振隧穿二极管（RTD）,通过离子注入将器件之间进行隔离,避免了传统台面型RTD中采用的台面刻蚀所带来的一些缺点,并且表现出良好的I-V特性,峰谷电流比为3．4．通过该方法制作的RTD将更有利于RTD的平面集成．     

基于光子带隙(PBG)结构的小型K波段谐振式带通滤波器

提出了一种新的基于光子带隙结构的K波段谐振式带通滤波器，给出了近似设计公式，并在半导体衬底上，采用微电子的工艺实现了这种结构。这种滤波器设计方法简单，体积小，整个长度接近谐振频率上的导波波长，加工方便，便于与其他电路集成，带内损耗小，阻带范围宽，带外抑制高。另外，本文的理论分析和实验结果均基于半导体衬底，可以直接应用于微波集成电路中。理论模拟与实际测量值基本吻合。     

The Colossal Piezoresistive Effect in Nickel Nanostrand Polymer Composites and a Quantum Tunneling Model

A novel nickel nanostrand-silicone composite material at an optimized 15 vol% filler concentration demonstrates a dramatic piezoresistive effect with a negative gauge factor (ratio of percent change in resistivity to strain). The composite volume resistivity decreases in excess of three orders of magnitude at a 60% strain. The piezoresistivity does decrease slightly as a function of cycles, but not significantly as a function of time. The material's resistivity is also temperature dependent, once again with a negative dependence.
The evidence indicates that nickel strands are physically separated by matrix material even at high volume fractions, and points to a charge transport mechanism that causes a large change in conductivity for a small relative change in the distance between filler particles. Combined with the temperature dependence data, this suggests that conduction in this composite material may be dominated by quantum tunneling effects. Based upon a statistical model of junction character distribution, a quantum tunneling percolation model is applied that accurately reflects the mechanical and thermal trends.     

基于碳纳米管高分子导电膜的压阻效应

研究了以一种碳纳米管为填充物的高分子导电膜的制备及导电膜的组份和处理条件对其导电性的影响.实验发现,当碳纳米管与环氧树脂的质量配比为1:30时,导电膜的电导率开始明显提高,当质量配比为1:36时,该导电膜的压阻效应就非常明显.     

矢量水听器的声压场特性研究

1引言 矢量水听器由声压水听器和质点振速水听器复合而成,声压水听器测量空间的声压,质点振速水听器测量声场中的质点振动速度,因此,矢量水听器共点、同步测量声场的声压标量和质点振速矢量.一般,矢量水听器是将声压水听器均匀布放在振速水听器(球型)周围.根据声学理论可知,由于振速水听器的声散射和二次辐射,会对声压水听器的测量结果产生影响.因此,需要对振速水听器的近场声压特性进行理论研究.本文从同振球型振速水听器的工作原理出发,对其声压场进行了理论计算,分析它对声压测量值的影响.     

Resonant Tunneling Spectroscopy to Probe the Giant Stark Effect in Atomically Thin Materials

Each atomic layer in van der Waals heterostructures possesses a distinct electronic band structure that can be manipulated for unique device operations. In the precise device architecture, the subtle but critical band splits by the giant Stark effect between atomic layers, varied by the momentum of electrons and external electric fields in device operation, has not yet been demonstrated or applied to design original devices with the full potential of atomically thin materials. Here, resonant tunneling spectroscopy based on the negligible quantum capacitance of 2D semiconductors in resonant tunneling transistors is reported. The bandgaps and sub-band structures of various channel materials could be demonstrated by the new conceptual spectroscopy at the device scale without debatable quasiparticle effects. Moreover, the band splits by the giant Stark effect in the channel materials could be probed, overcoming the limitations of conventional optical, photoemission, and tunneling spectroscopy. The resonant tunneling spectroscopy reveals essential and practical information for novel device applications.     

隧穿型量子效应薄膜材料制备技术

探讨了隧穿型量子效应薄膜材料制备技术,并应用分子束外延方法制备了典型结构外延材料GaAs基共振隧穿二极管,经过器件验证,得到了较好的结果.重点讨论了关键制备技术,包括束流精细控制和间歇式生长方式,主要是为了生长出更接近完美的晶体结构和晶体表面,并分析了测试结果和器件验证结果,最终得出整套隧穿型量子效应薄膜材料制备技术.     

矢量水听器自动校准系统的研究及实现

研制的矢量水听器自动校准系统在水声计量领域具有重要的应用价值,能够实现低频范围内矢量水听器的自动校准。利用动态信号采集卡采集被测信号和标准水听器的输出信号,对驻波管内的声场分布进行了测量分析,对系统的测量不确定度进行了分析评定,对声压灵敏度进行了比对测试。该系统校准矢量水听器的扩展不确定度为1.6dB。     

新型谐振式硅微机械加速度计

制作出一种新型结构的谐振式硅微加速度计，其输出频率信号可以克服微机电系统器件输出微弱信号检测的困难、采用双端固定音叉作为谐振器，在加速度作用下，质量块的惯性力通过悬臂梁施加于音叉轴向，利用音叉谐振频率的变化测量加速度．在每个音叉臂上制作了梳齿结构，用梳齿间的静电力激励音叉产生谐振，并利用其构成的电容检测其振动频率．该加速度计采用体硅工艺制作，文中给出了工艺流程、用有限元方法仿真估算，得到传感器的灵敏度约为2／gHz．     

Tunneling Diode Based on WSe2/SnS2 Heterostructure Incorporating High Detectivity and Responsivity

van der Waals (vdW) heterostructures based on atomically thin 2D materials have led to a new era in next‐generation optoelectronics due to their tailored energy band alignments and ultrathin morphological features, especially in photodetectors. However, these photodetectors often show an inevitable compromise between photodetectivity and photoresponsivity with one high and the other low. Herein, a highly sensitive WSe₂/SnS₂ photodiode is constructed on BN thin film by exfoliating each material and manually stacking them. The WSe₂/SnS₂ vdW heterostructure shows ultralow dark currents resulting from the depletion region at the junction and high direct tunneling current when illuminated, which is confirmed by the energy band structures and electrical characteristics fitted with direct tunneling. Thus, the distinctive WSe₂/SnS₂ vdW heterostructure exhibits both ultrahigh photodetectivity of 1.29 × 10¹³ Jones (I_ph/I_dark ratio of ≈10⁶) and photoresponsivity of 244 A W^?1 at a reverse bias under the illumination of 550 nm light (3.77 mW cm^?2).     

Resonant Tunneling of Holes in GaMnAs-Related Double-Barrier Structures

Using the multiband quantum transmitting boundary method (MQTBM), hole resonant tunneling through AlGaAs/GaMnAs junctions is investigated theoretically. Because of band-edge splitting in the DMS layer, the current for holes with different spins are tuned in resonance at different biases. The bound levels of the light hole in the quantum well region turned out to be dominant in the tunneling channel for both heavy and light holes. The resonant tunneling structure can be used as a spin filter for holes for adjusting the Fermi energy and the thickness of the junctions.