High-resolution 3-D direction-of-arrival determination for urbanmobile radio

The in-depth knowledge of the mobile radio channel is particularly important for radio communication modeling and advanced technology system design. We propose an accurate method to determine jointly the azimuth and elevation angle and the delay of waves incoming at the receiver. The method is applied to measurements of the complex impulse response of the mobile radio channel, performed on a planar array placed on a mobile in an urban cellular environment. The directions-of-arrival (DOA) were obtained by the means of a direction finding algorithm-two-dimensional (2-D) unitary ESPRIT. Two-dimensional spatial smoothing as an extension of ordinary spatial smoothing is utilized to decorrelate coherent waves. The application of 2-D unitary ESPRIT increases the angular resolution over conventional Fourier analysis or the scattering function by an order of magnitude and overcomes difficulties due to secondary lobes. The time delay is determined from wideband channel sounder measurements. The results confirm some assumptions on propagation mechanisms: (1) the wave-guiding property of streets (canyon effect), which is especially pronounced for long-delayed paths; (2) the variation of the number of incoming waves with their excess delay-the larger the excess delay, the lower the number of paths comprising an echo in the power delay profile; (3) if a single path remains, the privileged DOA is the direction of the street; (4) the exponential part of the power delay profile due to scatterers all around the receiver; and (5) the elevation dependence or the impinging power. In the tested receiver locations, paths with elevations between 0° and 40° dominate, containing about 90% of the received power     

A quasi-SOI power MOSFET for radio frequency applications formed byreversed silicon wafer direct bonding

A quasi-SOI power MOSFET for radio frequency (RF) applications was fabricated by reversed silicon wafer direct bonding (RSDB). Its breakdown voltage was more than twice that of the conventional SOI power MOSFET and its other dc characteristics were almost the same. Its maximum oscillation frequency was about 15% higher than that of the conventional SOI power MOSFET. The power-added efficiency (PAE) of the quasi- SOI power MOSFET was higher than the SOI one. It showed excellent PAE of 68% at a drain bias of 3.6 V     

Monolithic 3-D silicon photonics

A monolithic CMOS compatible process has been developed to realize vertically integrated devices in silicon. The method involves the implantation of an oxygen into a patterned silicon substrate to form buried guiding structures. These buried devices are separated from a surface silicon layer by an intervening layer of silicon dioxide formed through the implantation process. Photolithography and etching is used to define devices on the surface silicon layer. The method has been utilized to realize the vertically coupled microdisk resonators and a variety of microresonator-based integrated optical elements. A new method for extraction of the unloaded Q of a cavity from its measured spectrum is also described.     

射频识别技术的应用与发展研究

作为一种优秀的识别技术,射频识别具有识别距离远、对环境适应性强、数据存储量大、可以分别同时识别多个物体等多个优势,已广泛应用于零售、工业、物流、交通等许多领域。文章介绍了无线射频识别技术的组成部分、工作原理,研究了射频识别技术以其自身的特点和优势,分析了射频识别技术当前在国内外的发展应用状况和技术存在的问题,并研究分析了该技术在交通领域、零售业领域、信息管理领域应用要点和发展趋势。     

A micromachining technology for integrating low-loss GHz RF passives on non-high-resistivity low-cost silicon MCM substrate

A micromachining technology for integrating high-performance radio-frequency (RF) passives on CMOS-grade low-cost silicon substrates is developed. The technology can form a thick solid-state dielectric isolation layer on silicon substrate through high-aspect-ratio trench etch and refill. On the non-high-resistivity but low-loss substrate, two metal layers with an inter-metal dielectric layer are formed for integrating embedded RF components and passive circuits. Using the technology, two types of integrated RF filters are fabricated that are band-pass filter and image-reject filter. The band-pass filter shows measured minimum insertion loss of 3.8 dB and return loss better than 15 dB, while the image-reject filter exhibits steeper band selection and achieves better than −30 dB image rejection. A 50 Ω co-planar waveguide (CPW) on the substrate is also demonstrated, showing low loss and low dispersion over the measured frequency range up to 40 GHz. The developed technology proves a viable solution to implementing silicon-based multi-chip modules (MCM) substrates for RF system-in-package (RF-SiP).     

基于射频技术的车牌自动识别装置设计

基于射频技术提出了一种新型车牌自动识别装置的设计思路,并详细阐述了该装置的工作原理、硬件电路及软件的设计。利用单片机控制射频读写模块,读取车牌的数据信息,可以通过LCD显示读取的信息,根据读取的信息来识别车牌。此外,可根据需要修改读取的数据信息。适用于真假车牌的鉴别,各种停车场所的车辆管理等。该装置具有识别的准确度高、可靠性好、抗干扰强、成本低、便于携带等特点。     

低频射电阵列中的信道化宽带多波束形成技术

针对低频射电阵列海量数据、高带宽、多波束、实时处理的需求,设计了一种基于数字信道化的宽带数字多波束形成技术方案。针对射电天文学信号预处理的需求,该技术同时实现数字波束形成(Digital Beam Forming DBF)和频谱分析的功能,降低了射电阵列信号预处理运算复杂度,同时具有易于硬件实现,实时性高的特点,非常适合低频射电阵列应用。     

A wafer-scale 3-D circuit integration technology

The rationale and development of a wafer-scale three-dimensional (3-D) integrated circuit technology are described. The essential elements of the 3-D technology are integrated circuit fabrication on silicon-on-insulator wafers, precision wafer-wafer alignment using an in-house-developed alignment system, low-temperature wafer-wafer bonding to transfer and stack active circuit layers, and interconnection of the circuit layers with dense-vertical connections with sub-/spl Omega/ 3-D via resistances. The 3-D integration process is described as well as the properties of the four enabling technologies. The wafer-scale 3-D technology imposes constraints on the placement of the first lithographic level in a wafer-stepper process. Control of wafer distortion and wafer bow is required to achieve submicrometer vertical vias. Three-tier digital and analog 3-D circuits were designed and fabricated. The performance characteristics of a 3-D ring oscillator, a 1024 /spl times/ 1024 visible imager with an 8-/spl mu/m pixel pitch, and a 64 /spl times/ 64 Geiger-mode laser radar chip are described.     

基于射频识别技术的智能电子化图书馆系统

本文介绍了一种基于射频识别技术的智能电子化图书馆系统,其以射频模块FM1725芯片、单片机STC89C52为微控制器,外加振荡器电路、接口连接电路、天线和电源电路.     

3-D double-directional radio channel characterization for urban macrocellular applications

We measured the spatial properties of the three-dimensional (3D) double-directional radio channel in urban macrocell environments separately at both ends of the link. In this paper, we study propagation conditions pertaining to reception and transmission at the mobile terminal, measured using a wideband channel sounder and a dual-polarized spherical antenna array. We were able to refine the results of the measurements conducted at the base station, and extend the study to full double-directional 3D channels. Individual propagation paths could be identified precisely, in some cases even considerable scattering from lampposts was observed. Our results show that over-rooftop-dominated propagation often occurs via building roofs with LOS to the base station antenna, acting as strong secondary signal sources. Based on measurements along continuous routes we demonstrate that the dominant propagation mechanisms can vary considerably when the mobile moves in the environment. We also present typical directional properties of the 3D radio channel at the mobile terminal in urban macrocell environments characterized by street canyons, showing how the angular distribution of energy is correlated with the excess delay.     

3维激光振镜扫描系统的关键技术研究

为了设计可用于大幅面扫描的3维激光振镜扫描系统,深入研究了3维激光振镜扫描系统的动态响应性能及控制算法、校正算法,采用具有高响应性能的伺服机构作为系统的执行机构,合理地规划扫描路径以及扫描延时参量,设计了对扫描图形进行精确校正的扫描校正模型,开发出了一套能实现大幅面精确扫描的3维激光振镜扫描系统.该3维激光振镜扫描系统经过长期实验验证,运行稳定,其扫描重复定位精度不大于30靘,扫描精度可达100mm±0.1mm.结果表明,该3维激光振镜扫描系统在需要进行大幅面精确激光扫描行业中有重要应用价值.     

3维激光振镜扫描系统的关键技术研究

为了设计可用于大幅面扫描的3维激光振镜扫描系统,深入研究了3维激光振镜扫描系统的动态响应性能及控制算法、校正算法,采用具有高响应性能的伺服机构作为系统的执行机构,合理地规划扫描路径以及扫描延时参量,设计了对扫描图形进行精确校正的扫描校正模型,开发出了一套能实现大幅面精确扫描的3维激光振镜扫描系统。该3维激光振镜扫描系统经过长期实验验证,运行稳定,其扫描重复定位精度不大于30μm,扫描精度可达100mm±0.1mm。结果表明,该3维激光振镜扫描系统在需要进行大幅面精确激光扫描行业中有重要应用价值。     

Review of add-on process modules for high-frequency silicon technology

Add-on process modules as enhancements for standard high-frequency silicon integration processes are discussed. Such modules can cost-effectively be added without any interference with the core process before (pre-process modules), during (mid-process modules), or after (post-process modules) the circuit integration. In addition, layout options providing a most cost-effective means of enhancement are discussed. High-resistivity silicon substrates, ferromagnetic thin-film integration, bulk micromachining, saddle-add-on metallization, spacer-substrate integration, and metal layer shunting are presented as examples in those categories.     

基于射频指纹技术的卫星信号个体识别方法

现有射频指纹识别研究主要集中于射频指纹产生及提取的通信机理,忽略了实际应用中信号采集数据的清洗筛分、识别算法模型的效率等工程性问题。为此,分析了卫星通信号的载波信息提取的原理与方法,并针对现有射频指纹方法的不足,围绕卫星信号识别领域,利用海量采集的射频指纹数据,深入研究基于自组织神经网络的射频指纹识别算法,提出了对应的算法模型,并与现有常见的无监督算法进行了比较。结果表明,所提方法可以取得更优的算法聚类效果和时间开销,可作为设计实现卫星频谱管理系统的基础。     

Organic doped diode rectifier based on parylene-electronic beam lithogrpahy process for radio frequency applications

We have adapted a “peel-off” process to structure stacked organic semiconductors (conducting polymers or small molecules) and metal layers for diode microfabrication. The fabricated devices are organic diode rectifier in a coplanar waveguide structure. Unlike conventional lithographic process, this technique does not lead to destroy organic active layers since it does not involve harsh developer or any non-orthogonal solvent that alter the functionality of subsequentially deposited materials.This process also involves recently reported materials, as a p-dopant of an organometallic electron-acceptor Copper (II) trifluoromethanesulfonate, that play the role of hole injection layer in order to enhance the performances of the diode.Comparatively to self-assembled monolayers based optimized structures, the fabricated diodes show higher reproducibility and stability. High rectification ratio for realized pentacene and poly (3-hexylthiophene) diodes up to 10⁶ has been achieved. Their high frequency response has been evaluated by performing theoretical simulations. The results predict operating frequencies of 200 MHz and 50 MHz for pentacene and P3HT diode rectifiers respectively, with an input oscillating voltage of 2 V peak-to-peak, promising for RFID device applications or for GSM band energy harvesting in low-cost IoT objects.     

Integrated optical spectrum analyser using planar technology on oxidised silicon substrate

We report, for the first time, the achievement of an integrated optical spectrum analyser on oxidised silicon substrate. This device uses an entire planar technology fully compatible with microelectronic processes.     

无线传感器网络中射频技术的实现及研究

无线射频识别技术（RFID）和无线物联网技术（WSN）是构建物联网的两大关键技术。然而传统的无线识别技术不能满足无线物联网设备低能耗的严格要求。现提出了一种使用低功耗单片机MSP430F149实现无线识别技术,利用Zig Bee技术组建WSN网络,并且搭建单片机和Zig Bee模块接口,给出一种RFID和WSN融合方案。通过实际实验得出方案可实施性强、通信可靠。     

3英寸CdTe/Si复合衬底外延技术研究

在消除金属设备补焊残余应力的整体热处理过程中,降温速度需要控制在30~50 ℃/h,对一维平板状金属设备,影响降温速度的因素是外界环境温度以及与环境的对流换热系数。由红外测温技术获得的设备外表面温度及平板外流体的温度可计算出降温速度与平掠平板的流体速度成正比,从理论上找到一种容易实现的控制降温速度的方法。     

3英寸CdTe/Si复合衬底外延技术研究

报道了采用分子束外延法,在3 in硅衬底上通过As钝化、ZnTe缓冲层生长、CdTe生长、周期性退火等工艺进行CdTe/Si复合衬底制备技术研究情况,采用光学显微镜、X射线高分辨衍射仪、原子力显微镜、红外傅里叶光谱仪和湿化学腐蚀等手段对碲化镉薄膜进行了表征,测试分析结果表明碲化镉薄膜的晶向得到了较好的控制,孪晶得到了抑...