Passive 350 GHz Video Imaging Systems for Security Applications

Journal of Infrared, Millimeter, and Terahertz Waves - Passive submillimeter-wave imaging is a concept that has been in the focus of interest as a promising technology for personal security...     

一种面向液压储能器的122 GHz FMCW 测距雷达

针对液压储能器活塞位移测量过程中存在的高温、高压、油污等影响问题,提出了基于122 GHz FMCW 测距雷达的活塞位移测量方案。在分析雷达系统结构和工作原理的基础上,分别对调制信号单元、T/ R 收发单元、调理单元和ARM 实时处理单元进行了详细设计,一方面采用集成设计思路缩小了系统体积,满足了液压储能器内安装测试需求,另一方面通过设计聚焦透镜,提高了122 GHz 毫米波在液压储能器内部的穿透能力。实验结果表明,在2 m 液压储能器活塞测试中,122 GHz FMCW 测距雷达能够耐压30 MPa,测距误差不超过2 cm。     

CMOS图像传感器及应用

CMOS图像传感器是多功能、高性能的摄像器件。本文详细介绍了其工作原理及其在微型摄像机、数码相机、PC多媒体等中的应用。     

低成本的94GHzFMCW精密测距雷达

本文介绍组件和分系统技术的最新进展,使得实现30～100GHz频率范围的系统成为可能。并且开拓了以往由于毫米波系统过高的成本而买不起的产品市场。用一个全部集成固态化的94GHz FMCW收发机来验证这些技术。本文详细地介绍了该系统,包括设计思想、结构标准、传输煤质的选择和使用的半导体器件。对苛刻的军用环境条件的适应性、小尺寸以及很低的生产成本等方面的准则提出了见解。最后的产品是一部作用距离1km的调频连续波(FMCW)雷达,其距离分辨率<0.1%。这个单元装在一个一立方英寸的立方体内,其天线和低频电子部分不包含在内。低的生产成本使这种单元电路适合于军事上短距离反装甲车辆和引信系统应用以及许多民用生产方面的应用,例如汽车工业。     

A Short Distance CW-Radar Sensor at 77 GHz in LTCC for Industrial Applications

The paper presents a Continuous-Wave(CW)-Radar sensor for high accuracy distance measurements in industrial applications. The usage of radar sensors in industrial scenarios has the advantage of a robust functionality in wet or dusty environments where optical systems reach their limits. This publication shows that accuracies of a few micro-meters are possible with millimeter-wave systems. In addition to distance measurement results the paper describes the sensor concept, the experimental set-up with the measurement process and possibilities to increase the accuracy even further.     

An all solid-state 330 GHz frequency multiplying Chain for 664 GHz radiometers application

An all solid-state 330 GHz ×6 × 2 × 2 frequency multiplying chain is constructed and tested and it is used as a local oscillator (LO) in 664 GHz radiometers for cirrus clouds and cloud ice detecting. The frequency multiplying chain consists of a W-band sextupler, followed by a power-combined amplifier which delivers 460–540 mW output power, and two cascaded 165 GHz and 330 GHz balanced frequency doublers. The 165 GHz two-ways power-combined doubler applies four three-anode in series GaAs Schottky diodes to generate 50–63 mW output power in the frequency range 160–176 GHz, and its tested typical efficiency is 11.5%. The cascaded 330 GHz doubler uses a four-anode in anti-series arranged GaAs diode to generate 2.5–4.5 mW output power in the frequency range 320–352 GHz, and its tested typical efficiency is 6.0% and the maximum value is 8.0% at 328 GHz. The output power of the multiplying chain is high enough to pump the 664 GHz heterodyne radiometer for space application.     

330 GHz单片集成分谐波混频器

根据反向并联二极管的外围结构和材料构成,以四端口S参数包的形式建立了二极管结外围无源结构的三维电磁模型,与非线性仿真软件中的肖特基结模型结合起来建立太赫兹二极管对的完整模型,这样的处理方法提高了计算机仿真的准确性。分谐波混频电路制作在12m厚度的砷化镓基片上,单片电路悬置安装在本振和射频中间剖开的减高波导腔体内。在本振5 mW功率注入时混频单片在330 GHz的频带范围内最小插损为10 dB。因为单片集成电路以四个梁式引线与波导外壁柔性连接,一端固定在波导壁上,混频单片电路能够释放腔体随温度变化而产生的机械应力。     

330 GHz高性能二次谐波混频器设计

采用反向并联肖特基二极管对设计了一种330 GHz二次谐波混频器。混频器电路采用微带结构,使用波导-微带探针耦合的形式进行过渡;采用50 μm厚的石英作为基板,有效减小了电路体积;采用HFSS和ADS对电路进行仿真和谐波平衡仿真。仿真结果显示,混频器在310~350 GHz范围内的变频损耗优于9.5 dB,所需本振(LO)功率为3 dBm,有效降低了对本振的要求。     

330GHz砷化镓单片集成分谐波混频器

在太赫兹频段,二极管尺寸与波长相比已不能忽略,二极管的封装会引入很大的寄生参量,因此需建立二极管三维模型提取寄生参数.同时人工装配难度增大,会增加电路不确定性.采用12μm砷化镓单片集成悬置微带线结构,基于电子科技大学与中国电子科技集团第十三研究所自主联合设计的肖特基二极管研制330 GHz砷化镓单片集成分谐波混频器.实测结果显示在5 mW本振功率的驱动下,在328 GHz可得到最小变频损耗10.4 dB,在320~340 GHz范围内,单边带变频损耗小于14.7 dB.     

CMOS图像传感器的最新进展及其应用

CMOS图像传感器是20世纪70年代在美国航空航天局（NASA）的喷气推进实验室（JPL）诞生的，与CCD图像传感器几乎同步，标准CMOS大规模集成电路技术的不断发展大大改善了CMOS图像传感器的图像质量，CMOS图像传感器的高度集成化减小了系统的复杂性，降低了制造成本，仅为普通CCD图像传感器的1／20，对获得的图像信息读出及处理变得简单而快捷，能设计出灵活的小型成像系统，它具有单一工作电压，功耗低，像素缺陷率低，可与其他CMOS集成电路兼容，对局部像素的编程可随访问等优点。本文主要介绍CMOS图像传感器的发展现状，最新进展，市场前景及其在医学上的应用。     

激光退火在背照式CCD图像传感器中的应用研究

激光退火是消除背照式电荷耦合器件(CCD)图像传感器背面势阱的重要工艺。文章研究了激光退火工艺中不同的激光波长、能量密度、光斑交叠率对掺杂杂质激活效率、器件表面形貌、成像质量及紫外量子效率的影响。研究结果表明，在浅结注入的情况下，355 nm波长激光激活效率要优于532 nm激光，但是355 nm激光比532 nm激光更易在较低能量密度时使硅片出现龟裂现象。采用2 J/cm²能量密度、50%～65%交叠率，355 nm激光能有效激活离子注入的硼离子，背照式CCD图像传感器成像均匀性好，紫外量子效率明显提升。     

CMOS图像传感器用像素级双采样存储技术

多次曝光技术是扩展CM O S APS图像传感器动态范围较为有效的方法,但多于两次的曝光,信号处理复杂,使传感器的帧频受到限制,而像素级双采样存储技术将两次曝光采样及图像组合处理在像素内实现,在获得高动态范围的同时,可有效提高图像实时处理的速度,并且可以工作于高速同步曝光模式。     

2.4 GHz载频FMCW信号发生器的设计与实现

随着FMCW雷达的应用领域越来越广泛,对于FMCW信号发生器的性能要求也越来越高。采用了DDS激励PLL的混合式频率合成技术对合成器相位噪声、杂散损耗和线性度等性能指标进行分析,在此基础上设计并实现了2.4 GHz载频FMCW信号发生器。其中DDS芯片AD9910产生低频段的线性调频信号,PLL芯片HMC820LP6CE通过倍频将低频段调频信号倍频到高频段,STM32为控制器。实测结果表明,该系统具有频率分辨率高、相噪低、杂散损耗小、捷变频时间短、线性度高的特点。其近端杂散为-59.64 d Bc,远端杂散为-55.02 d Bc,相位噪声在100 k Hz处为-95.57 d Bc/Hz,在400 k Hz处为-118.38 d Bc/Hz。     

Channel Measurement and Path Loss Modeling from 220 GHz to 330 GHz for 6G Wireless Communications

Terahertz (THz) communication has been envisioned as a key enabling technology for sixthgeneration (6G).In this paper,we present an extensive THz channel measur...     

石墨烯太赫兹调制器及330 GHz无线通信系统

现有太赫兹无线通信系统通常采用微波倍频或直接调源的方式。本文从太赫兹波空间调制技术出发,研究了一种基于直接调制技术的太赫兹无线通信系统。重点探索了一种基于石墨烯/半导体硅的复合结构(GOS),研究出调制速率达到1 MHz,调制深度50%以上,工作频带覆盖0.2 THz~2 THz频段的新型全光学太赫兹调制器。在此基础上,构建了330 GHz载波频率的太赫兹无线通信系统,实现了1 Mbps的通信速率。     

FMCW系统在工业中的应用

本文首先讨论了提高测量精度的方案,然后列举测量吹氧炼钢炉料位、高压输电线振动和冰层厚度的应用实例,最后介绍利用直达信号的单、双天线的固态系统以及用多波束测量多目标、多参数的FMCW系统.     

RF CMOS Varactors for 2 GHz Applications

CMOS varactors are important components for the integration of tunable RF filters and VCOs. This paper presents a performance evaluation and comparison of three different types of CMOS varactors based on measurements. The tested varactor types are: (i) p⁺-to-n-well junction, (ii) standard mode nMOS, and (iii) accumulation mode nMOS. The performance of each varactor type with respect to capacitance ratio and quality factor Q is evaluated at 2 GHz. Further, it is shown how these varactor types must be configured in LC-tank circuits for optimum performance. Finally, the three varactor types are compared and it is concluded that the Standard Mode nMOS type seems to the best choice for RF applications.     

A Novel End-shorted Printed Open Loop Antenna for IEEE 802.15 2.4 GHz Wireless Sensor Network Platform Applications

In this paper, a novel antenna design with a coupling feeding mechanism for WSN applications at IEEE 802.15 2.4 GHz operation has presented and implemented. By adjusting coupling element, impedance matching for RF input 50 ohm can be obtained. By tuning the length of the resonant strip, resonant frequency at 2.4 GHz can be easily controlled. In addition, a novel end-shorting between the end of the resonant strip and the ground plane provide a half wavelength current loop for EM compatibility and small clearance area on main circuit board. The whole dimension of the proposed antenna occupied just only a small area of 16.5 × 2 mm². The proposed antenna design has excellent performances in bandwidth of 140 MHz @ 10 dB, radiation efficiency of > 50% and omni-like radiation patterns. For the viewpoints in practical WSN application, user’s effects including user’s head and body tissue were discussed and explained. For radiation power absorption, user’s head plays a key role to affect the EM power distribution in radiation efficiency and front/back ratio in free space. As for impedance detuning, body tissue and user’s head both lead to resonant frequency shifting. Further detailed discussions and explanations for the proposed antenna will be explained in Sects. 2 and 3.     

一种应用于安防监控的CMOS图像传感器的自动曝光算法研究

针对传统自动曝光算法难以兼顾实时性和平滑性的缺点,设计了一种结合直接计算法和可变步长调节法的综合性算法,研究了算法原理,给出了算法流程.该算法可以通过改变步长参数,自由设定将图像亮度调节到目标亮度的时间,使其能够适用于各种不同的应用场合.在基于FPGA的CMOS图像采集平台上完成了算法实现,实验结果证明采用该算法可以使图像亮度快速平稳地接近理想亮度,成像效果很好.     

基于GaAs肖特基二极管的330GHz接收前端技术研究

基于GaAs肖特基二极管,设计实现了310~330 GHz的接收机前端.接收机采用330 GHz分谐波混频器作为第一级电路,为降低混频器变频损耗,提高接收机灵敏度,分析讨论了反向并联混频二极管空气桥寄生电感和互感,采用去嵌入阻抗计算方法,提取了二极管的射频、本振和中频端口阻抗,实现了混频器的优化设计,提高了变频损耗仿真精度.接收机的165 GHz本振源由×6×2倍频链实现,其中六倍频采用商用有源器件,二倍频则采用GaAs肖特基二极管实现,其被反向串联安装于悬置线上,实现了偶次平衡式倍频,所设计的倍频链在165 GHz处输出约10 dBm的功率,用以驱动330 GHz接收前端混频器.接收机第二级电路采用中频低噪声放大器,以降低系统总的噪声系数.在310~330 GHz范围内,测得接收机噪声系数小于10.5 dB,在325 GHz处测得最小噪声系数为8.5 dB,系统增益为(31±1)dB.