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传统的球形共形天线阵列馈电网络复杂,每个天线单元需要单独馈电和控制相位,导致天线阵列效
率较低。文中提出了一种采用口径耦合馈电的单馈球面共形全向天线阵。为球形天线阵列设计了一个1 分30 的馈
电网络且直接集成在了阵列内部。这样可以通过一个端口给所有的天线单元馈电,从而降低了馈电的复杂度,提高
了天线效率。阵列的方向图在x-y 平面上是全向的。x-y 平面的增益变化小于1 dB,x-z 平面的半功率波瓣宽度约为
120°,实现了比传统全向更大的空间覆盖范围。天线的方向图最大增益为1 dBi。 相似文献
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提出一种新型宽带、结构紧凑的基片集成波导(SIW)背腔阵列天线的设计方法。所设计的SIW 阵列由紧密相连的背腔构成馈电网络,每个背腔上开宽缝作为辐射单元。SIW 背腔天线单元紧密排列,主要通过单元间感性耦合窗耦合馈电。SIW 背腔既是辐射单元又能实现能量分配,不需加载额外的馈电网络,因此该阵列结构十分紧凑。工作在20 GHz 频段的2×2 SIW 耦合馈电阵和4×4 SIW 耦合馈电阵已加工实现,仿真和测试结果表明所提出的SIW阵列设计方法简单、阵列结构紧凑、天线辐射性能良好。另外,本文研究了高增益大规模阵列天线的组阵方法。在2×2 SIW 耦合馈电阵的基础上,采用8×8 SIW 并联馈电网络加载天线子阵的方法设计了16×16 宽带高增益SIW 阵列天线并进行了加工测试。结果表明,采用这种组阵方法,天线阵阵元排布紧密,天线具有带宽宽、增益高、损耗低等优点。 相似文献
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超宽带平面天线阵列的微带馈电 总被引:1,自引:0,他引:1
设计、分析、制作了3种类型的4单元平面超宽带天线阵列,采用宽度按指数渐变的微带线网络馈电,馈电网络和天线单元设计在同一介质基板上,易于加工和集成.给出了天线单元、馈电网络各自的输入特性,并将其与整个阵列输入特性进行了比较.仿真和测量结果表明:这3种类型的天线阵在3.1~10.6 GHz绝大部分频段内的回波损耗小于-10 dB,最大不超过-8 dB,天线阵的增益在8~12 dB之间,远大于单元的增益. 相似文献
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针对阵列天线馈电网络比较复杂的问题,设计了一款24 GHz新型串并馈结合的微带天线阵,并进行了理论研究和仿真测试。该天线阵采用了串并联混合馈电网络,天线子阵和馈电网络的电流分布均采用了切比雪夫分布,有效抑制了旁瓣电平。同时将馈电网络与串馈天线子阵直接连接在一起,达到了小型化的目的,并减小了馈电网络的损耗。仿真结果表明:天线阵的增益可达到21.7 dBi,在中心频率24.1 GHz附近,E面和H面的副瓣电平分别为-20.3 dB 和-26.2 dB。该天线阵体积小,性能可靠,可用于24 GHz汽车防撞雷达。 相似文献
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为解决X波段机载雷达变极化速度较慢的问题,设计了一种可实现脉间变极化的偶极子天线阵.该天线阵采用正交排列薄片电偶极子阵元,并加装垂直贴片和反射板,通过同轴线耦合巴伦进行馈电.利用改造后的阵元组成了一个4×4的16元矩形栅格、矩形边界均匀平面正交极化天线阵,利用射频开关控制馈电线路实现快速变极化,通过高频结构仿真(HFSS)软件对其进行参数优化和建模仿真,结果显示,该天线阵具有较低的驻波比和副瓣电平以及较高的天线增益,可以作为机载正交极化相控阵雷达天线的参考设计,或用作正交极化阵列天线的子阵. 相似文献
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本文为工作于K波段的车载防撞雷达收发前端设计并制作了一款高增益低副瓣易集成的微带贴片阵列天线。该天线采用串并结合馈电形式,在满足各阵元激励同相不等幅的基础上,既有效减小了馈电网络的损耗,又实现了天线小型化。测试结果表明,该8×6元微带天线阵带宽为24.2~24.8GHz(VSWR1.5),最大增益可达20.2d B,第一副瓣电平-20d B,E面、H面的半功率波瓣宽度为16.7°和11.8°,其尺寸仅60mm×45mm。该阵列天线凭借其高增益、低副瓣、、结构紧凑体积小及性能稳定等优点,经验证实用性强,在汽车防撞雷达系统中有广阔的应用前景。 相似文献
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设计了一种基于FSS 覆层的高增益EBG 谐振天线。设计了一种在预定频段内谐振的FSS 单元,作为覆层加载到微带贴片天线上方。仿真结果显示,在5GHz 频点,加载覆层的天线增益为11.43dB。接着,还研究了FSS 覆层在稀疏阵列中的应用,在这个结构中,采用一个2×2 的阵元间距较大的天线阵作为馈源。对该结构进行加工和测试,结果显示天线阵增益为18. 54dB。同时,阵列在E 面和H 面的副瓣分别为-9.17dB 和-12.04dB,避免了栅瓣的产生。 相似文献
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Meihua Shen Wilfred Pau Nicolas Gani Jianping Wen Shashank Deshmukh Thorsten Lill Jian Zhang Hanming Wu Guqing Xing 《半导体技术》2004,29(8)
This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration. 相似文献
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White organic light-emitting devices based on fac tris(2- phenylpyridine) iridium sensitized 5,6,11,12-tetraphenylnap -hthacene 总被引:1,自引:0,他引:1
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V. 相似文献
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Complete approach to automatic identification and subpixel center location for ellipse feature 总被引:1,自引:0,他引:1
XUE Ting WU Bin SUN Mei YE Sheng-hua 《光电子快报》2008,4(1):51-54
To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction. 相似文献
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In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy. 相似文献
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High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center. 相似文献
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This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors. 相似文献
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Credence Systems Corporation 《半导体技术》2004,29(9)
Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V. 相似文献
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YUXiao-hua XIANGYu-qun 《半导体技术》2005,30(2):30-32,37
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB. 相似文献
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It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer (LDV). 相似文献