HgCdTe红外焦平面用锥形节流致冷杜瓦组件

介绍了一种用于HgCdTe红外焦平面的致冷器杜瓦组件的设计和试验情况.该组件通过采用锥形结构,包括锥形杜瓦和锥形节流致冷器两部分,提高了降温速度,有效地缩短了组件的轴向尺寸,结构更加紧凑,尤其适用于轴向尺寸受到限制的红外导引头.     

电潜泵测试仪的电流信号发生器设计

根据电潜泵测试仪的需要,提出一种基于TLV5637数模转换器的电流信号发生器电路设计方法。采用AT89C51模拟SPI通信访问TLV5637,将仪器采集到的数字信号转换为模拟电压信号,再通过电流环电路把模拟电压信号转化成电流信号。详细描述了硬件和软件的具体实现方案,其中包括微控制器与D/A转换器的接口连接与通信,电流环电路和软件基本代码。经过多次实验,结果表明该电流信号发生器能够准确产生所需的电流信号,完全满足仪器的要求并具有很高的精度和通用性。     

Facile Two‐Step Synthesis of All‐Inorganic Perovskite CsPbX3 (X = Cl,Br, and I) Zeolite‐Y Composite Phosphors for Potential Backlight Display Application

Recently developed CsPbX₃ (X = Cl, Br, and I) perovskite quantum dots (QDs) hold great potential for various applications owing to their superior optical properties, such as tunable emissions, high quantum efficiency, and narrow linewidths. However, poor stability under ambient conditions and spontaneous ion exchange among QDs hinder their application, for example, as phosphors in white‐light‐emitting diodes (WLEDs). Here, a facile two‐step synthesis procedure is reported for luminescent and color‐tunable CsPbX₃–zeolite‐Y composite phosphors, where perovskite QDs are encapsulated in the porous zeolite matrix. First zeolite‐Y is infused with Cs⁺ ions by ion exchange from an aqueous solution and then forms CsPbX₃ QDs by diffusion and reaction with an organic solution of PbX₂. The zeolite encapsulation reduces degradation and improves the stability of the QDs under strong illumination. A WLED is fabricated using the resulting microscale composites, with Commission Internationale de I'Eclairage (CIE) color coordinates (0.38, 0.37) and achieving 114% of National Television Standards Committee (NTSC) and 85% of the ITU‐R Recommendation BT.2020 (Rec.2020) coverage.     

64dB二进制增益控制带有DCOC和AB类buffer的可编程增益放大器

本文设计了一款二进制增益控制,带有直流失调消除（DCOC）电路以及AB类输出buffer的可编程增益放大器。该放大器采用二极管连接负载的差分放大器结构,电路性能对温度变化及工艺偏差不敏感。根据测试,通过6位数字信号控制,电路可以实现-2dB ~ 61dB的增益动态范围,增益步长1dB,步长误差在 0.38dB以内,最小3dB带宽为92MHz,在低增益模式下,IIP3可达17dBm,1dB压缩点可达5.7dBm。DCOC电路可使该放大器应用于直接变频接收机中,而AB类输出buffer则降低了电路的静态功耗。     

Effects of Sn-doping on morphology and optical properties of CdTe polycrystalline films

Sn-doped CdTe polycrystalline films were successfully deposited on ITO glass substrates by close space sublimation. The effects of Sn-doping on the microstructure, surface morphology, and optical properties of polycrystalline films were studied using X-ray diffraction, scanning electron microscopy, and ultraviolet-visible spectrophotometry, respectively. The results show that the lower molar ratio of Sn and CdTe conduces to a strongly preferential orientation of (111) in films and a larger grain size, which indicates that the crystallinity of films can be improved by appropriate Sn-doping. As the molar ratio of Sn and CdTe increases, the preferential orientation of (111) in films becomes weaker, the grain size becomes smaller, and the crystal boundary becomes indistinct, which indicates that the crystallization growth of films is incomplete. However, as the Sn content increases, optical absorption becomes stronger in the visible region. In summary, a strongly preferential orientation of (111) in films and a larger grain size can be obtained by appropriate Sn-doping (molar ratio of Sn : CdTe = 0.06 : 1), while the film retains a relatively high optical absorption in the visible region. However, Sn-doping has no obvious influence on the energy gap of CdTe films.     

激光对光电探测器的损伤阈值研究

本文研究了1.06μm和0.53μm激光对硅pin光电二极管以及硅雪崩光电管的永久性损伤效应,测出了损伤阈值。实验发现,光电探测器的PN结受到激光热烧伤是造成其永久性损伤的重要因素,损伤阈值的大小与激光波长、脉冲宽度以及光电探测器结构有关。     

SDH/SONET支路时钟抖动衰减数字锁相环设计

提出了一种新的光纤通信网络中SDH/SONET支路时钟抖动衰减设计方法.采用全数字锁相环技术和可编程的方法,根据不同类型的PDH信号,配置相应的增益和衰减因子,使得时钟的抖动衰减收敛速度可调节,能快速的达到国际电信联盟ITU-T标准规定的抖动范围.对于E3信号,滤波组合为100 Hz～800 kHz时,最大峰峰抖动为0.05 UI,滤波组合为10～800 kHz时,最大峰峰抖动小于10-3 UI.该方法电路实现结构简单,可广泛应用于光纤通信领域.     

A 3D Hybrid of Chemically Coupled Nickel Sulfide and Hollow Carbon Spheres for High Performance Lithium–Sulfur Batteries

Lithium–sulfur batteries are a promising next‐generation energy storage device owing to their high theoretical capacity and the low cost and abundance of sulfur. However, the low conductivity and loss of active sulfur material during operation greatly limit the rating capabilities and cycling stability of lithium–sulfur batteries. In this work, a unique sulfur host hybrid material comprising nanosized nickel sulfide (NiS) uniformly distributed on 3D carbon hollow spheres (C‐HS) is fabricated using an in situ thermal reduction and sulfidation method. In the hybrid material, the nanosized NiS provides a high adsorption capability for polysulfides and the C‐HS serves as a physical confinement for polysulfides and also a 3D electron transfer pathway. Moreover, NiS has strong chemical coupling with the C‐HS, favoring fast charge transfer and redox kinetics of the sulfur electrode. With a sulfur loading of up to 2.3 mg cm^?2, the hybrid material‐based lithium–sulfur batteries offer a capacity decay as low as 0.013% per cycle and a capacity of 695 mA h g^?1 at 0.5 C after 300 cycles. This unique 3D hybrid material with strong chemical coupling provides a promising sulfur host for high performance lithium–sulfur batteries.     

基于RF MEMS开关的新型双频带功率放大器

RF MEMS开关具有低损耗、低功耗、尺寸小和易于集成等优点而被广泛应用于各种可重构射频电路及系统中。通过分析比较电容并联式和串联式RF MEMS开关两种电路结构的射频性能,设计了一种基于RF MEMS开关的新型功率放大器,使用RF MEMS开关控制匹配网络来实现双工作频带的转换。结果表明,设计的功率放大器在2.35GHz和1.25GHz两个工作频带下,功率附加效率(PAE)和输出功率(Pout)可分别达到72%、67%及40.8、42.7dBm。该功率放大器具有较高的功率附加效率和输出功率,适用于多频带的射频系统,对RF MEMS器件在可重构系统中的应用具有一定参考价值。     

特柔软型钢丝铠装复合电缆设计探讨

本文主要探讨特柔软型钢丝铠装复合电缆的设计,根据特殊用户实际应用情况,设计出大拉力、超柔软钢丝铠装电缆,设计过程中不仅考虑电缆所应有的电性能,同时还要考虑电缆高强度抗张情况和应用中处于反复收放状态,而且所设计的电缆还要满足恶劣环境.