某机载抗振捷变频频综器设计

设计了1种用于某机载电子设备上的捷变频频率综合器。该合成器采用快捕、隔振技术以及数字锁相和谐波混频技术,在很小的体积内实现了合成器的低相噪、捷变频和抗振等性能指标。测试结果为:输出频率Ku波段,带宽480 MHz,跳频点数49点,相噪优于-96dBc/Hz/1kHz,杂波抑制优于-70 dBc,捷变频时间小于50μs。     

混合电路形式的Ku 波段低噪声放大器的设计

采用低噪声HEMT 场效应管和低噪声放大器单片的混合电路形式开展Ku 波段低噪声放大器的设计。设计出的低噪声放大器产品取得了很低的噪声(噪声系数≤1. 29 dB)、较大的线性动态范围、较小的增益带内起伏和尺寸等优越性能,且在40 GHz 频率范围内无条件稳定。该产品成功应用于某型号装备中,很好地提高了该装备的信号接收能力。它也可应用于相应频段的卫星通讯、空间遥感及雷达等的接收系统中。     

Cellular dynamics of Ku: characterization and purification of Ku-eGFP

Ku is a predominantly nuclear protein that functions as a DNA double-strand-break (DSB) binding protein and regulatory subunit of the DNA-dependent protein kinase (DNA-PK). DNA-PK is involved in synapsis and remodeling of broken DNA ends during nonhomologous end-joining (NHEJ) of DNA DSBs. It has also recently been demonstrated that Ku plays roles in cytoplasmic and membrane processes, namely: interaction with matrix metalloproteinase 9, acting as a co-receptor for parvoviral infection, and also interacting with cell polarity protein, Par3. We present a method for creating stable expression of Ku-eGFP in CHO cells and extend the procedure to purify Ku-eGFP for in vitro assaying. We demonstrated that Ku-eGFP localizes to the nucleus of HeLa cells upon microinjection into the cytoplasm as well as localizing to laser induced DNA damage. We also characterized the diffusional dynamics of Ku in the nucleus and in the cytoplasm using fluorescence correlation spectroscopy (FCS). The FCS data suggest that whereas the majority of Ku (70%) in the nucleus is mobile and freely diffusing, in a cellular context, there also exists a significant slow process fraction (30%). Strikingly, in the cytoplasm, this immobile/slow moving fraction is even more pronounced (45%).     

A KU KLUX KLAN CIPHER

Discussion of a cipher system used by the Ku Klux Klan during the 1920's     

Ku/Ka双频段防弹天线罩复合材料性能

为解决Ku/Ka双频段天线罩的防弹和透波问题,本文通过波导法研究材料的介电性能,并利用HFSS软件对双频工作的复合材料进行透波性能仿真设计,并采用试验与理论计算验证了超高分子量聚乙烯（UHMWPE）防弹和透波性能。研究表明：UHMWPE的介电性能优异,适用于Ku/Ka双频段天线罩。HFSS仿真设计表明,7 mm UHMWPE的Ku频段损耗为0.2 dB,Ka频段损耗为0.6 dB,仿真结果与实际测试结果吻合。防弹打靶试验表明,面密度为5.6 kg/m²的UHMWPE防弹等级优于1级,实测V₅₀值为546 m/s。     

Left‐handed meta‐surface loaded with ring resonator modelling for satellite application

A new geometry of compact meta‐surface, loaded with the ring resonator for satellite application (Ku‐band), is presented in this paper. The diamond‐shaped meta‐surface is designed by the metallic ring resonator with metallic ground plane separated by a dielectric substrate layer, while epoxy resin fibre is utilized as a dielectric substrate layer. The proposed meta‐surface structure is successfully simulated, fabricated, and measured. Effects of the design specifications on the surface current and field distribution are also investigated elaborately. Theoretical and simulated results show that the diamond‐shape structure resonance is at 15.84 GHz, whereas the measured results are slightly shifted around at 15.87 GHz. The designed meta‐surface structure also exhibits the left‐handed characteristics at 15.88 GHz, where the estimations of permittivity is ?4 + 0.28j, permeability is ?19.2 ? 134.6j, and negative index is ?5.51 ? 3.86j. Further, the lumped element equivalent circuit model of the proposed meta‐surface unit cell is explained. Moreover, the 10 × 10 mm² meta‐surface single‐unit‐cell prototype is compact in size and the impact on the performance by modifying the meta‐surface structure is investigated. Therefore, the meta‐surface integrated antenna shows resonance frequency bands from 14.0 to 14.50 GHz, which is used as INSAT‐4A communication satellite uplink frequency.     

Highly c-axis oriented W-type hexaferrites SrNi2ScxFe16-xO27 (x = 0.70, 0.75, 0.80 and 0.85) for the design of self-biased circulator at Ku band

Highly oriented W-type hexaferrites SrNi₂Sc_xFe_16-xO₂₇ (SrW, x = 0.70, 0.75, 0.80 and 0.85) are fabricated via ceramic process and magnetic orientation to meet design requirements of self-biased circulators. The orientation degree reaches 0.81 when Sc³⁺ substitution content x is 0.75. The XRD refinement results in consideration of orientation illustrate the strong c-axis anisotropy texture of SrW. SEM images show significant uniformity in grain growth with c-axis stays vertical to sample plane. Consequently, the corresponding remanence ratio M_r/M_s reaches as high as 0.92, which is indispensable to reduce low field loss (LFL) as much as possible in the design of self-biased circulators. According to simulation results, the self-biased microstrip circulator based on this SrW material (x = 0.75) realizes ideal functions in circular transmission operating at Ku band.     

基于APT控制技术的Ku/Ka双频机载动中通系统设计

随着航空用户对上网需求的逐步增加,结合航天制造、卫星通信及惯性稳定平台技术,设计了一种基于APT控制技术的Ku/Ka双频机载动中通系统。该系统具有较高的高动态响应及精准卫星捕获、跟踪能力；APT控制技术融合陀螺稳定、漂移补偿、多数据融合及精准伺服控制关键技术,系统采用程序跟踪、动态跟踪控制策略,可根据ModMan控制指令在不同载体扰动情况下迅速完成Ku、Ka天线切换及对星,保障链路通信正常,以最佳带宽服务理念为航空用户提供多层次通信服务保障。目前已完成样机研制和地面跑车模拟、摇摆台试验,技术指标符合总体设计要求具有良好的应用前景。     

Ku70对辐射诱导的BRCA1表达的影响

为探讨核蛋白Ku70对经γ射线照射后乳腺癌易感基因BRCA1表达的影响,本研究通过靶向升高或降低Ku70,观察了Ku70基因对BRCA1蛋白和mRNA表达水平的影响,以及Ku70对照射后SGC7901、EC109、H460 3种肿瘤细胞BRCA1表达的影响.结果表明:经siKu70处理的3种肿瘤细胞BRCA1的蛋白和m...