W波段交错双栅返波振荡器高频系统

将矩形交错双栅结构作为慢波电路并提出与之配套的过渡结构和输出耦合器,设计了利用带状电子注工作在W波段的返波振荡器。提出的过渡结构和耦合器解决了该类直波导型器件的信号传输衰减大、反射强等难题。相对于传统圆形电子注器件,该器件得到了较大的功率提升。利用三维粒子模拟计算的方法,在电流12 mA时通过调节工作电压,在92~98 GHz频带内得到了数W的稳定平均功率输出,信号中心频率非常接近设计频率,且单色性好,谐波分量小。     

级联亚波长平面介质栅偏振分束器研究

提出了一种纳米厚度金属层连接的级联亚波长平面介质光栅三明治结构,利用该结构中纳米金属连接层上下界面处的表面等离子共振的互作用形成多波长共振的特点设计了适用于光通信波段（1 300～1 600nm）高性能的宽带偏振器和宽带偏振分束器。利用严格耦合波理论分析发现偏振分束器带宽主要由金属连接层厚度控制,光栅厚度基本不影响偏振分束器带宽,只影响共振深度和共振波长。该结论为后续的制备提供了理论指导和借鉴作用。     

动静叶栅优化改型及其性能分析

本文对动静叶栅分别进行优化改型,并对改型前后叶栅的气动性能进行数值分析。动静叶栅的优化改型基于正反问题相结合的流函数方法,性能分析一方面基于单排叶栅定常粘性流动的数值计算,另一方面基于动静叶栅相互干扰非定常粘性流动的数值计算。算例结果表明,经过优化改型后的动静叶栅的气动性能,无论在定常流动条件下还是在非定常流动条件下,相比改型前均有较大幅度的改善。     

叶片弯、掠对压气机端壁流动的影响

通过壁面静压测量、流场显示及气动探针测量研究了不同掠型叶片组成的平面扩压叶栅特性。结果表明,前掠 叶栅流道中横向压力梯度减弱,型面压力沿叶展呈反“C”型,有利于减弱角区低能流体堆积,但中径处损失有所增加; 弯掠叶片强化了上述趋势,其降低端部损失和延缓角区分离的能力更强,应从优化设计角度对其进行深入研究。     

Large stereoscopic LED display by use of parallax barrier of aperture grille type (Invited Paper)

We propose a large parallax barrier by use of aperture grille. Main advantages of using aperture grille include no reflection and no absorption in apertures, as well as wide viewing angle. These advantages are investigated with theoretical calculations and experiments by use of several kinds of LED panels, such as a fine-pitch LED panel and a 140-inch large LED panel. Limitations of viewing angle by parallax barrier are analyzed in conventional black stripes on a transparent substrate type and in aperture grille type. Experimental results straw use of aperture grille increases contrast and reduce reflection on the aperture surface.     

Effects of Annealing on Schottky Characteristics in A1GaN/GaN HEMT with Transparent Gate Electrode

A1GaN/GaN heterostructure transistors are promising for power and switching applications. In addition, the transparent wide band-gap A1GaN/GaN heterostructure systems have received considerable attention to transparent electronics. Nowdays, Al-doped ZnO （AZO） thin film plays an increas- ingly important role in various fields of transparent electronics.The AZO-gated A1GaN/GaN HEMT with good dc characteristics and frequency character- istics has been reported. Annealing is widely used to improve the electri- cal characteristics of A1GaN/GaN HEMTs. It is re- ported that the Schottky leakage current can be re- duced by over four orders of magnitude by annealing in an A1GaN/GaN heterostructure with ITO/Ni/Au electrode. Pei et al. reported that the transparency of Ni/ITO gates of A1GaN/GaN HEMTs has been sig- nificantly improved after annealing. However, the evaluation of Schottky C V characteristics was ab- sent. Up to now, few results are reported on the Schot- tky annealing characteristics of AZO in A1GaN/GaN HEMT. Thus the effects of annealing on the leakage current, transparency and interface states character- istics need further study.     

具有poly-Si_(1-x)Ge_x栅的应变SiGe p型金属氧化物半导体场效应晶体管阈值电压漂移模型研究

针对具有poly-Si1-x Ge x栅的应变Si Ge p型金属氧化物半导体场效应晶体管(PMOSFET),研究了其垂直电势与电场分布,建立了考虑栅耗尽的poly-Si1-x Ge x栅情况下该器件的等效栅氧化层厚度模型,并利用该模型分析了poly-Si1-x Ge x栅及应变Si Ge层中Ge组分对等效氧化层厚度的影响.研究了应变Si Ge PMOSFET热载流子产生的机理及其对器件性能的影响,以及引起应变Si Ge PMOSFET阈值电压漂移的机理,并建立了该器件阈值电压漂移模型,揭示了器件阈值电压漂移随电应力施加时间、栅极电压、polySi1-x Ge x栅及应变Si Ge层中Ge组分的变化关系.并在此基础上进行了实验验证,在电应力施加10000 s时,阈值电压漂移0.032 V,与模拟结果基本一致,为应变Si Ge PMOSFET及相关电路的设计与制造提供了重要的理论与实践基础.