C波段小型化低相噪全相参频率综合器

提出了一种小型低相噪、低杂散的C波段全相参频率综合器设计方案。基带信号由DDS芯片产生,通过对环路滤波器和电路印制板的优化设计改善相噪和杂散性能,并与PLL输出的C波段点频信号进行上变频,得到所需信号。介绍了实现原理、相位噪声模型及设计方法。测试结果表明,在7.8GHz处,频综相位噪声≤-103dBc/Hz@100kHz,杂波抑制≤-61dBc。     

低相噪全相参毫米波频率合成源研究

研制出一种小步进全相参毫米波频率合成源.本振部分,对直接数字式合成频率、参考分频比和环路分频比进行三重调节,抑制了直接数字频率合成的杂散,提高了频率分辨率;发射部分,采用二次混频电路,避免了调谐电压预置,简化了电路,并保证了发射信号和本振信号相参.该系统输出在Ka频段,带宽400MHz,步进<1MHz.测试相噪<-90dBc/Hz@10kHz、-97dBc/Hz@100kHz,杂散为-60dBc,跳频时间<15us.     

L波段小步进频率合成器的设计

采用了锁相环(PLL)结合直接数字频率合成(DDS)的方法实现L波段小步进频率合成器,分析了此种频率合成器的相位噪声和杂散指标。介绍了具体的电路设计过程。实验测试表明,实现的L波段频率合成器结合了锁相环式和直接数字式频率合成的优点,步进间隔1 kHz,相位噪声在10 kHz处可达-98 dBc/Hz,杂散抑制-70 dBc,具有相噪低、杂散抑制好、步进小等特点。     

一种Ku波段小型化多通道微波模块设计

本文提出了一种Ku波段微波模块的设计方法,该方法对频率综合器与接收机进行一体化设计,用直接数字频率合成(DDS)技术产生一路中频复杂波形信号,锁相环产生的本振信号上变频得到发射激励信号;采用滤波放大合成方式合成相参时钟信号。实现了微波模块的低相噪,低杂散,小型化。该模块相噪优于-95 dBc/Hz@1 kHz,杂散优于-70 dBc,跳频时间小于100 ns。     

高频谱纯度小步进频率合成器的设计与实现

讨论了一种杂散抑制高,频率步进小及相位噪声低的频率合成器的设计方法。设计采用混合式频率合成技术,研制实现了S波段频率合成器,实验结果表明,该频率合成器输出信号频率步进100 Hz,相位噪声优于-115dBc/Hz@10kHz,杂散抑制大于80dBc,跳频时间140μs。     

C波段宽带低噪声频率源的研制

介绍了利用锁相环和混频技术,实现C波段低相噪跳频源的方案,该方案通过两个环路同时实现跳频及混频,步进36MHz,输出频率4428~5220MHz,具有低相位噪声,低杂散等特点。和以往锁相频率合成的不同之处在于:以往混频时采用主环信号4428~5220MHz作为混频器的RF端,而本方案为可以充分抑制辅环杂散,通过放大器将主环信号放大作为混频器的本振LO端。测试结果表明达到系统对项目的指标要求,该频率合成方案是可行的。     

一种应用于全相参雷达的毫米波频综设计

结合DDS、PLL、倍频及混频技术,研制了一种低相噪和低杂散的毫米波全相参雷达频综. 主要包括一个毫米波源、一个线性调频信号发生器以及为接收机提供第二本振的微波源,整个源的相参时钟采用外接的一个100 MHz恒温晶振提供. 分析和估算了毫米波信号的相位噪声和杂散. 测试结果表明信号输出频率范围为34.855~34.865 GHz,步进100 KHz,输出功率高于16 dBm, 相位噪声大约为-92 dBc/Hz@10 KHz.     

小型化脉冲雷达快速频综

提出了一种新颖的应用于频率步进脉冲雷达的快速频率合成器.采用乒乓切换的方式实现频率步进雷达要求的快速切换时间,采用分频加混频的方式,将乒乓切换后的信号进行分频以提升杂散及相位噪声并扩展频率步进,利用低频段的小步进信号与高频段的低相噪点频进行混频实现X波段信号杂散、相噪及频率步进的兼顾并满足小型化的要求.对传统实现小步进...     

PLL驱动DDS的低相噪小步进LFM信号源设计

介绍了一种低相噪线性调频(LFM)雷达信号源的产生和实现方案。通过分析DDS输出信号频谱和杂散,采用HMC704控制VCO的方法设计了1 GHz的锁相环路(PLL)作为DDS的时钟驱动电路,并对环路滤波器和AD9910硬件电路优化设计改善杂散和相噪性能。通过计算寄存器参数和分析SPI总线时序,利用FPGA对DDS和PLL高速配置。最后给出了系统实物图和测试方法,实测结果表明:该线性调频源输出幅度大于-3dBm,频率步进为1kHz,相位噪声优于-103dBc/Hz@1kHz,各项指标满足实际工程要求。     

高性能X波段直接式频综的设计

介绍一种X波段直接式频综的设计方案,对其输出杂散进行分析,并给出研制结果,在10GHz的输出频率上,偏离载频1kHz处的相噪为－108dBc/Hz,杂散优于－70dBc,跳频时间小于0．7μs,可捷变40个点。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.