S波段宽带低交叉极化印刷偶极子阵列天线的设计

设计出一种新型宽带低交叉极化印刷偶极子天线,该天线采用双层平面Balun 偶极子结构,不仅具有平面Balun偶极子的宽频带特性,同时也降低了天线交叉极化电平.使用该天线单元设计制作S波段16元线阵.测试结果表明,阵列天线工作带宽达到50%,交叉极化电平小于-43 dB.实验结果验证了该天线阵的宽带低交叉极化特性.     

宽带单脊波导缝隙天线阵设计

给出了一种新型脊波导宽边缝隙天线阵设计,天线阵被分成几个子阵形式,通过膜片的激励方式,由一个半高波导功分器馈电.设计、加工了一根16元波导天线阵,测试得到11.3%的阻抗带宽(VSWR＜1.5),天线辐射方向图最大副瓣电平低于-12 dB,具有低于-40 dB的交叉极化特性.     

一种S波段宽带微带贴片天线阵列的设计

介绍了一种宽带微带贴片天线单元及2元阵列的设计方法,天线工作的中心频率为rl_5OHz（S波段）。天线单元设计中采用口径耦合理论和层叠贴片天线结构,有效增大了天线的阻抗带宽。仿真结果表明该天线阵列实际增益达到11．9dB;在2．27～2．78GHz频率范围内端口驻波比小于2,相对带宽为20．4％;交叉极化电平为-31dB,证明该天线阵具有宽频带、低交叉极化等优良性能。     

高隔离度低交叉极化DRA单元设计

主要阐述了一种高隔离度低交叉极化双极化介质谐振器天线的设计方法,通过采用Ｕ形和Ｈ形混合缝隙馈电,该天线实测隔离度优于46.8dB,两个极化的实测带宽大于12.5％(V端口S11小于-10dB的实测阻抗带宽是5.36～6.08GHz,相对带宽约为12.8%;而H端口的为5.47～6.2GHz,相对带宽约为12.5%),交叉极化电平分别低于-21.4 dB 和 -18.1dB。     

共面波导馈电的多模天线设计

设计了一种可工作在共面波导和耦合槽线两种模式下的耦合渐变槽线天线,该天线采用双端口共面波导馈电.仿真和测试结果显示:"和"端口馈电时,5.8～7.7 GHz的S11均小于-10 dB,波束在最大辐射上均具有较好的极化纯度,交叉极化电平小于-25 dB;"差"端口馈电时,S11在5 GHz后,除个别频点外均小于-10 dB,差波束在天线辐射方向上具有-20 dB的零深,并随着工作频率增加,两个波瓣逐渐靠近,旁瓣电平逐渐降低,方向性更加明显.     

S／X双波段双极化共口径天线阵的设计

提出一种S/X双波段双极化共口径天线阵的新设计,以紧凑的三层结构实现了1:3的频率比.X波段采用双层贴片,并在下层贴片上开缝以提高其极化端口间的隔离度.S波段采用缝隙,刻蚀在X波段贴片的地板上,从而减少了阵列层数,简化了天线结构.仿真结果验证了本设计的有效性.X波段的相对阻抗带宽(S11≤-10dB)达15.5%(中心频率为9.6GHz),频带内隔离度大于25dB的带宽为1.2GHz,隔离度最大值达40dB.S波段为单层结构,相对阻抗带宽为5.5%(中心频率为3.3GHz).频带内隔离度优于27dB.试验阵列双波段交叉极化电平均低于-30dB.     

宽带超低副瓣天线阵设计

描述了由16元线阵组成的L频段宽带超低副瓣天线阵的设计,给出了设计过程中所解决的各项关键技术及所采用的技术途径,以及一些设计数据和测试结果。天线近场测试表明,所研制的天线在优于25%频带内天线峰值副瓣电平低于-38 dB,垂直面扫描±30°时,天线峰值副瓣电平低于-35 dB。     

共用口径S／X双波段双极化微带天线阵

介绍了一种新的应用于合成口径雷达的双波段双极化(DBDP)共用口径微带天线阵,工作于S波段和X波段.为了实现S/X波段的奇数频率比(1∶3),在S波段采用正交的微带振子天线,在X波段采用双极化方形微带贴片天线;为获得较宽的带宽,该二天线均采用双层结构.在馈电方式上,S波段采用邻近耦合馈电,X波段采用同轴探针和口径耦合馈电.对天线进行了仿真,设计、加工和测试,仿真结果与实测结果吻合良好.实测的S波段和X波段阻抗带宽分别达8.9%和17%,实测的极化隔离度在两个波段内均优于20 dB,实测的S波段和X波段交叉极化电平分别在-26 dB和-31 dB以下.本研究验证了这种具有奇数频率比的共用口径DBDP微带天线阵的可行性,对这种DBDP微带天线阵在SAR系统中的应用具有重要的参考意义.     

S波段矢量阵列天线单元的设计

设计了一个工作在S波段矢量阵列的天线单元,利用HFSS软件进行优化和仿真。实测结果表明,该天线在E面和H面的交叉极化电平分别小于-26 dB和-23 dB,两个端口之间的隔离度大于32 dB。该数据满足组成矢量阵列的要求。     

基于超材料馈电网络的全向双极化天线阵设计

为了减小对天线阵辐射特性的影响,提出并设计了一种平行平板传输线结构的超材料串联馈电网络,基于超材料传输线设计了零相移传输线,利用零相移传输线设计了串联馈电网络。基于该馈电网络设计了一种全向水平/垂直双极化4元天线阵。天线阵由4个全向双极化天线单元和2个超材料串联馈电网络组成。全向双极化天线单元由折顶偶极子天线和缝隙电容加载的零相移圆环天线构成。利用HFSS仿真软件对该天馈系统进行了仿真,结果表明,该天线阵的中心工作频率为3.5 GHz,最大增益为7 dB,交叉极化电平小于-35 dB,隔离度大于40 dB,不圆度小于±1.2 dB,满足5G通信对基站天线和多入多出天线的要求。     

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.