Photoluminescence properties of solid-state Tb^3＋ doped NaY（MoO4）2

A series of Tb^3＋ doped Na Y（Mo O4）2 are synthesized by a solid-state reaction at 550 °C for 4 h, and their luminescent properties are investigated. The phase formation is carried out with X-ray powder diffraction analysis, and there is no other crystalline phase except Na Y（Mo O4）2. Na Y（Mo O4）2：Tb^3＋ can produce the green emission under 290 nm radiation excitation, and the luminescence emission peak at 545 nm corresponds to the 5D4→7F5 transition of Tb^3＋. The emission intensity of Tb^3＋ in Na Y（Mo O4）2 is enhanced with the increase of Tb^3＋ concentration, and there is no concentration quenching effect. The phenomena are proved by the decay curves of Tb^3＋. Moreover, the Commission International de I＇Eclairage（CIE） chromaticity coordinates of Na Y（Mo O4）2：Tb^3＋ locate in the green region.     

Optical simulation of phosphor layer of white LEDs

A Matlab(2009a) program was developed to simulate the photons emitted by the LED chips.The photons’transmission,reflection,and refraction in phosphor layers with different shapes were calculated in this program.The CCT was calculated at different emergent angles with different layer profiles,such as planar layer, hemispherical layer(with different diameters),half ellipsoid layer and other irregular shapes.As a consequence of optimization of angular color uniformity,the trend of configuration of the phosphor layer was discussed and analyzed.     

硼掺杂硅薄膜及其在叠层电池隧道结中的应用

Boron-doped hydrogenated silicon films with different gaseous doping ratios（B2H6/SiH4） were deposited in a plasma-enhanced chemical vapor deposition（PECVD） system.The microstructure of the films was investigated by atomic force microscopy（AFM） and Raman scattering spectroscopy.The electrical properties of the films were characterized by their room temperature electrical conductivity（σ） and the activation energy（Ea）.The results show that with an increasing gaseous doping ratio,the silicon films transfer from a microcrystalline to an amorphous phase,and corresponding changes in the electrical properties were observed.The thin boron-doped silicon layers were fabricated as recombination layers in tunnel junctions.The measurements of the I-V characteristics and the transparency spectra of the junctions indicate that the best gaseous doping ratio of the recombination layer is 0.04,and the film deposited under that condition is amorphous silicon with a small amount of crystallites embedded in it.The junction with such a recombination layer has a small resistance,a nearly ohmic contact,and a negligible optical absorption.     

Effect of different processing methods for the hole transporting layer on the performance of double layer organic light-emitting devices

The hole transporting layer （HTL） of organic light-emitting device （OLED） was processed by vacuum deposition and spin coating method, respectively, where N,N＇-biphenyl-N, N＇-bis（3-methylphenyl）- 1, l＇-biphenyl-4,4＇ -diamine （TPD） and poly （vinylcarbazole） （PVK） acted as the hole-transport materials. Tris-（8-hydroxyquinoline）- aluminum （Alq3） was utilized as both the light-emitting layer and the electron transporting layer. The basic structure of the device cell was： indium-tin-oxide （1TO）/PVK ： TPD/Alq3/Mg：Ag. The electroluminescent （EL） characteristics of devices were characterized. The results showed that the peak of EL spectra was located at 530 nm, which conformed to the characterizing spectrum of Alq3. Compared with using vacuum deposition method, the green emission with a maximum luminance up to 26135 cd/m2 could be achieved at a drive voltage of 15 V by selecting proper solvent using spin-coating technique, and its maximum lumi nance efficiency was 2.56 lm/W at a drive voltage of 5.5 V.     

He—Ne激光穿透动物组织深度的实验

For more efficient use of low power He.Ne laser in clinical truatme.at the dbpth of its peuolration in animal and human tisue was measured by both photo-electric（reported cleswhere）and photogrephic record.It was found that photographic effect could ba obtninod in the human tissue through the skin to a depth of aroun 27 mm within 10-15 minutes radia tion.The ponetrance of pork fat was the highest（117mm）followed by rabbit muscle（100mm）and lean pork（84mm）/The dog and humsn muscle tissues werc more resistant to penetrate being 20mm for dog meat 15mm for dog skin and 34mm for human tissue through the skin,Since higher expo;sure effect was obtained by prologning the time of exposure the time of radiation is an important factor in clinical treatment with He-Ne laser.     

高调光比发光二极管驱动控制器的设计与实现

This paper presents a high dimming ratio light emitting diode （LED） drive controller chip with digital mode dimming （DMD）. The chip is composed of a boost power converter and a dimming control block. A novel constant on time （COT） control strategy is proposed for boost converter to achieve high dimming ratio. In addition, a fast enough load transient response of the converter power stage ensures its high dimming ratio. The COT control circuit operates mainly based on two current-capacitor timers and a finite state machine （FSM）. The LED drive controller chip is designed and fabricated in 1.5μm bipolar CMOS-DMOS （BCD） process with a die area of 1.31 x 1.43 mm^2. Experimental results show that the proposed LED drive system works well. And, as expected, the minimum LED dimming on time of 1.0μs and the corresponding dimming ratio of 1000 ： 1 at 1 kHz dimming frequency are successfully achieved.     

Design and implementation of Single-Buffered routers

A Single-Buffered （SB） router is a router where only one stage of shared buffering is sandwiched between two interconnects in comparison of a Combined Input and Output Queued （CIOQ） router where a central switch fabric is sandwiched between two stages of buffering. The notion of SB routers was firstly proposed by the High-Performance Networking Group （HPNG） of Stanford University, along with two promising designs of SB routers： one of which was Parallel Shared Memory （PSM） router and the other was Distributed Shared Memory （DSM） router. Admittedly, the work of HPNG deserved full credit, but all results presented by them appeared to relay on a Centralized Memory Management Algorithm （CMMA） which was essentially impractical because of the high processing and communication complexity. This paper attempts to make a scalable high-speed SB router completely practical by introducing a fully distributed architecture for managing the shared memory of SB routers. The resulting SB router is called as a Virtual Output and Input Queued （VOIQ） router. Furthermore, the scheme of VOIQ routers can not only eliminate the need for the CMMA scheduler, thus allowing a fully distributed implementation with low processing and commu- nication complexity, but also provide QoS guarantees and efficiently support variable-length packets in this paper. In particular, the results of performance testing and the hardware implementation of our VOIQ-based router （NDSC~ SR1880-TTM series） are illustrated at the end of this paper. The proposal of this paper is the first distributed scheme of how to design and implement SB routers publicized till now.     

53-GHz平衡式考毕兹振荡器的设计与测试

A 53 GHz Colpitts oscillator implemented in a SiGe：C BiCMOS technology is presented. Limited by a 26.5 GHz frequency analyzer, the oscillator was measured indirectly through an on-chip mixer. The mixer downconverted the oscillating frequency to an intermediate frequency （IF） below 26.5 GHz. By adjusting the local oscillating （LO） frequency and recording the changes of IF frequency, the oscillator＇s output frequency （RF） was determined. Additionally, using phase noise theory of mixers, the oscillator＇s phase noise was estimated as -58 dBc/Hz at 1 MHz offset and the output power was about -21 dBm. The chip is 270 ×480μm in size.     

十六氯酞菁锌有机半导体材料的合成及其气敏性研究

Due to the difficulty in synthesizing perhalogenated metallophthalocyanine, the method of ammonium molybdate solid phase catalysis was introduced, and by using tetrachlorophthalic anhydride and urea as the raw materials, hexadecachloro zinc phthalocyanine （ZnPcCl16） was synthesized. Components of the composite were analyzed by energy spectrum, and its functional group structures and absorption peaks were characterized by IR and UV-vis spectroscopy. The thin films of gas sensors were prepared in a vacuum evaporation system and evaporated onto SiO2 substrates, where sensing electrodes were made by MEMS micromachining. The optimal conditions for the films are： substrate temperature of 150 ℃ evaporation current of 95 A and film thickness of 50 nm. The result showed that the sensors were ideally sensitive to Cl2 gas and could detect the minimum concentration of 0.3 ppm.     

大面积非光刻纳米电极间隙的制备

A lithography-independent and wafer scale method to fabricate a metal nanogap structure is demonstrated. Polysilicon was first dry etched using photoresist （PR） as the etch mask patterned by photolithography. Then, by depositing conformal SiO2 on the polysilicon pattern, etching back SiO2 anisotropically in the perpendicular direction and removing the polysilicon with KOH, a sacrificial SiO2 spacer was obtained. Finally, after metal evaporation and lifting-off of the SiO2 spacer, an 82 nm metal-gap structure was achieved. The size of the nanogap is not determined by the photolithography, but by the thickness of the SiO2. The method reported in this paper is compatible with modern semiconductor technology and can be used in mass production.     

Software Radio——Software Radio： A Review of Design Considerations and Digital Hardware Choices

This paper reviews the requirements for Software Defined Radio （SDR） systems for high-speed wireless applications and compares how well the different technology choices available- from ASICs, FPGAs to digital signal processors （DSPs） and general purpose processors （GPPs） - meet them.     

具有频率调谐的GNSS接收机双模复数滤波器

A fifth/seventh order dual-mode OTA-C complex filter for global navigation satellite system receivers is implemented in a 0.18μm CMOS process.This filter can be configured as the narrow mode of a 4.4 MHz bandwidth center at 4.1 MHz or the wide mode of a 22 MHz bandwidth center at 15.42 MHz.A fully differential OTA with source degeneration is used to provide sufficient linearity.Furthermore,a ring CCO based frequency tuning scheme is proposed to reduce frequency variation.The measured results show that in narrow-band mode the image rejection ratio（IMRR）is 35 dB,the filter dissipates 0.8 mA from the 1.8 V power supply,and the out-of-band rejection is 50 dB at 6 MHz offset.In wide-band mode,IMRR is 28 dB and the filter dissipates 3.2 mA.The frequency tuning error is less than±2%.     

集成片上天线的低成本低功耗超高频射频识别标签

This paper presents an EPC Class 1 Generation 2 compatible tag with on-chip antenna implemented in the SMIC 0.18 μm standard CMOS process.The UHF tag chip includes an RF/analog front-end, a digital baseband, and a 640-bit EEPROM memory.The on-chip antenna is optimized based on a novel parasitic-aware model.The rectifier is optimized to achieve a power conversion efficiency up to 40% by applying a self-bias feedback and threshold compensation techniques.A good match between the tag circuits and the on-chip antenna is realized by adjusting the rectifier input impedance.Measurements show that the presented tag can achieve a communication range of 1 cm with 1 W reader output power using a 1 × 1 cm2 single-turn loop reader antenna.     

应用于低中频和零中频DVB调谐器中8阶信道滤波器设计

An eighth order active-RC filter for low-IF and zero-IF DVB tuner applications is presented, which is implemented in Butterworth biquad structure. An automatic frequency tuning circuit is introduced to compensate the cut-off frequency variation using a 6-bit switched-capacitor array. Switched-resistor arrays are adopted to cover different cut-off frequencies in low-IF and zero-IF modes. Measurement results show that precise cut-off frequencies at 2.5, 3, 3.5 and 4 MHz in zero-IF mode, 5, 6, 7 and 8 MHz in low-IF mode can be achieved, 60 dB frequency attenuation can be obtained at 20 MHz, and the in-band group delay agrees well with the simulation. Two-tone testing shows the in-band IM3 achieves -52 dB and the out-band IM3 achieves -55 dB with -11 dBm input power. This proposed filter circuit, fabricated in a SMIC 0.18μm CMOS process, consumes 4 mA current with 1.8 V power supply.     

一种测量差分片上螺旋电感类器件的简便方法

This paper proposes a simple method of measuring differentially-excited on-wafer RF CMOS spiral inductor-like components.This method requires only two common ‘G-S-G＇ probes and an ordinary two-port VNA.Using a network instead of a detailed equivalent circuit, this method completes the de-embedding with only one ‘Through＇ dummy, and thus the measurements are greatly simplified.By designing the ports ‘Open＇ or ‘Shortcircuited＇ deliberately, a multi-port transformer can be transformed into three two-port networks with different terminators.Then, couplings between the two coils can be solved, and the differentially-excited scattering parameters（S-parameters） can be constructed.Also, a group of differential inductors and transformers were designed and measured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.     

EEFA： Energy Efficiency Frame Aggregation Scheduling Algorithm for IEEE 802.11n Wireless Network

Packet size is restricted due to the error-prone wireless channel which drops the network energy utilization. Furthermore, the frequent packet retransmissions also lead to energy waste. In order to improve the energy efficiency of wireless networks and save the energy of wireless devices, EEFA （Energy Efficiency Frame Aggregation）, a frame aggregation based energy-efficient scheduling algorithm for IEEE 802.11n wireless network, is proposed. EEFA changes the size of aggregated frame dynamically according to the frame error rate, so as to ensure the data transmission and retransmissions completed during the TXOP and reduce energy consumption of channel contention. NS2 simulation results show that EEFA algorithm achieves better performance than the original frame-aggregation algorithm.     

The Data Age of Mobile Cellular Network in Germany and China： Policies,Technologies and Markets （Part I）

The UMTS auction in 2000 brought approximately 100 billion DM （Deutsche Mark） for the German National Treasury. T-Mobile （D1-Netz）, Vodafone （D2-Netz）, E-Plus （E1-Netz） and 02 （E2-Netz） have gradually evolved from GSM to full-fledged UMTS operators over the past years. The conglomerate of China Telecom was split twice. China acceded to WTO and promulgated the FITE Provisions. MIIT （Ministry of Industry and Information Technology） became the regulator and China Netcom was incorporated into China Unicorn in 2008. Most recently the layout of 3G future has been reconfirmed by MIIT. Voice service has remained the main source of income in both countries and operators have continued to focus on voice quality and network availability in their respective 2G networks. Because value-added and higher-speed data applications have been gaining market attention, 2.5G and 3G infrastructure has increasingly become the focal network strategy for the operators since the beginning of the new century. Germany has rolled out WCDMA/UMTS services on a large scale in the consumer market, while China has adopted all three 3G standards （TD-SCDMA, WCDMA/UMTS, CDMA2000）, which shall gradually capture a wider 3G subscriber base. The summary shows that the development of the cellular technology and market in Germany and China can be discussed in three distinct historical periods. The conclusion suggests that the case of the cellular technology appears to be consistent with and applicable to a number of arguments widely disputed in economics and management related to technology and innovation, such as dominant design, technology waves/ S-Curve, disruptive technologies, Technology Adoption Life Cycle.     

Survivable Virtual Network Mapping Using Optimal Backup Topology in Virtualized SDN

Software-Defined Network architecture offers network virtualization through a hypervisor plane to share the same physical substrate among multiple virtual networks. However, for this hypervisor plane, how to map a virtual network to the physical substrate while guaranteeing the survivability in the event of failures, is extremely important. In this paper, we present an efficient virtual network mapping approach using optimal backup topology to survive a single link failure with less resource consumption. Firstly, according to whether the path splitting is supported by virtual networks, we propose the OBT-I and OBT-II algorithms respectively to generate an optimal backup topology which minimizes the total amount of bandwidth constraints. Secondly, we propose a Virtual Network Mapping algorithm with coordinated Primary and Backup Topology （VNM-PBT） to make the best of the substrate network resource. The simulation experiments show that our proposed approach can reduce the average resource consumption and execution time cost, while improving the request acceptance ratio of VNs.     

A 10-20 Gb/s PAM2-4 transceiver in 65 nm CMOS

This paper presents the design of a 10 Gb/s PAM2, 20 Gb/s PAM4 high speed low power wire-line transceiver equalizer in a 65 nm CMOS process with 1 V supply voltage. The transmitter occupies 430 × 240 μm2 and consumes 50.56 mW power. With the programmable 5-order pre-emphasis equalizer, the transmitter can compensate for a wide range of channel loss and send a signal with adjustable voltage swing. The receiver equalizer occupies 146 × 186μm^2 and consumes 5.3 mW power.     

一种用于中枢神经信号再生的四通道微电子系统

This paper presents a microelectronic system which is capable of making a signal record and functional electric stimulation of an injured spinal cord. As a requirement of implantable engineering for the regeneration microelectronic system, the system is of low noise, low power, small size and high performance. A front-end circuit and two high performance OPAs （operational amplifiers） have been designed for the system with different functions, and the two OPAs are a low-noise low-power two-stage OPA and a constant-gm RTR input and output OPA. The system has been realized in CSMC 0.5-μm CMOS technology. The test results show that the system satisfies the demands of neuron signal regeneration.