SiGe的BiCOMS技术的S波段低噪声放大器的设计

文中介绍了一种基于锗硅BICMOS的宽带低噪声放大器的设计。此放大器工作在2.7 GHz～3.5 GHz的频带,采用0.18μm的锗硅工艺和cascode结构来增加其反向隔离度,并且使用了射极电阻负反馈和电阻并联反馈改善其带宽和线性度。仿真结果展示了其在通带范围内16.3 dB的增益和小于-10 dB的端口反射。此放大器噪声系数为2.8 dB左右,并使用5 V电源电压。     

A theoretical study of double-pass thulium-doped fiber amplifiers

An efficient fluoride-based thulium-doped fiber amplifier (TDFA) is theoretically demonstrated using a double-pass scheme. A reflector is incorporated in the double-pass TDFA to allow double propagation of the test signal in the gain medium and thus improve the gain of the TDFA. The small signal gain improvement of more than 15 dB is obtained in the 1465 nm region. A gain as high as 42 dB is obtained in this region with 300 mW of 1050 nm pump using 20 m of thulium-doped fiber. However, a noise figure penalty of approximately 1 dB is also obtained in this wavelength region. Differential equations are solved using the Runge-Kutta method in the theoretical analysis. The theoretical result is in agreement with the experimental result.     

Multiwavelength fiber laser using S-band erbium-doped fiber amplifier and semiconductor optical amplifier

A multiwavelength fiber ring laser that is based on an S-band erbium-doped fiber amplifier (EDFA) and a semiconductor optical amplifier (SOA) is developed. An optical switch is used to switch the multiwavelength fiber laser between S-band and L-band. This fiber laser can stably lase seven wavelengths in the S-band or 28 wavelengths in the L-band. Additionally, the lasing wavelengths with a signal-to-noise ratio of over 33 dB and a wavelength spacing of 100 GHz are demonstrated experimentally. The average powers of the lasing wavelength in the S-band and the L-band are −7.53 and −12.15 dBm, respectively.     

用于S波段放大器的掺铥重金属氧化物玻璃发光性质研究

制备了不同Tm³⁺离子浓度的PbO-Bi₂O₃-Ga₂O₃-GeO₂重金属氧化物玻璃，根据吸收光谱计算了JO强度参量以及Tm³⁺离子在玻璃中的自发辐射概率、荧光分支比及荧光辐射寿命等光谱参数.通过测量1470nm波段发射光谱，计算表明该玻璃系统在S波段有较宽的荧光半高宽和较大的峰值受激发射截面，但玻璃中荧光寿命随稀土离子浓度增加呈线性下降，而交叉弛豫速率随浓度的平方迅速增加.研究结果仍可表明掺铥重金属氧化物玻璃是一种理想的S波段宽带光纤放大器用基质材料. 关键词： 重金属氧化物玻璃 3+离子')" href="#">Tm³⁺离子 S波段光纤放大器 光谱性质     

S频段测控系统频率配置优化设计

阐述了What if软件与传统软件相比做频率规划的优点;以S频段测控系统下行链路为例给出了频率规划的方法和步骤;在此基础上给出了可变中频配置方案解决多目标同时测控中可能产生的交调干扰,最后指出了合理的频率规划对提高群时延指标的重要性。     

航天测控网测量体制的改进探讨

从航天测量系统和数据处理技术着手，探讨了对我国S频段航天测控网的外测系统进行改进的技术途径，提出了在测量体制上的几种改进措施，给出了相应的观测方程，并分析了它们的优越性。     

S-band multiwavelength Brillouin Raman Fiber Laser

In this paper we propose and demonstrate an S-band Brillouin-Raman Fiber Laser (BRFL). The S-band BRFL utilizes a Dispersion Compensating Fiber (DCF) as the non-linear gain medium in a linear cavity configuration and amplified by two 1425 nm, 380 mW pumped Raman Fiber Amplifiers (RFAs). A Brillouin Pump (BP) signal of 1515 nm at 12 dBm in power is injected into the setup to generate Stokes lines via the Stimulated Brillouin Scattering (SBS) process. The S-band BRFL is able of generating a Brillouin comb with 32 Stokes lines with a flat peak output power of − 18 dBm. The best BP to Stokes power ratio of the system is determined to be 50:50, while a ratio of 70:30 is observed to generate Stokes with a higher peak power, but at the expense of the number of wavelengths. The S-band BRFL has many potential applications as multiwavelength sources for communications and sensors.     

S波段系列SiC MESFET器件研制

SiC材料具有宽禁带、高电子饱和漂移速度、高击穿电压、高热导率和相对低的介电常数等优点,使SiC MESFET在微波功率等方面的应用得到了快速发展。采用国产SiC外延片,解决了欧姆接触、干法刻蚀及损伤修复等一系列工艺难题;针对不同应用背景,研制出总栅宽分别为1、5、15、20mm系列SiC MESFET样管。在2GHz脉冲状态下,300μs脉宽、10%占空比、20mm栅宽器件单胞输出功率超过80W,功率密度大于4W/mm;15mm栅宽器件在3.1~3.4GHz频带脉冲功率输出超过30W。该研究结果为SiC器件的实用化奠定了基础。     

宽带宽与新波段光纤放大器进展

宽带、高速、长距离和智能化是目前光纤通信系统发展的趋势所在。迅速膨胀的信息服务量使宽带成为最迫切的需求,新波段与长增益带宽光纤放大器的研究炙手可热。本文阐述了近期各波段光纤放大器以及拉曼放大器的进展,并揭示了光纤放大器向短波段和混合型发展的趋势。     

圆波导TM01-TE11模式变换器

提出了一种在圆波导中添加金属分割片及半边金属管壳的结构以实现圆波导TM01-TE11模式转换。通过金属分割片将圆波导分成两个半圆区域：其中一个半圆区域为空波导,另一半圆区域为填充一定厚度金属管壳的空波导。在S波段对设计的中心频率为2.8 GHz的物理模型进行数值模拟与实验研究,模拟结果表明：在中心频率2.8 GHz转换效率为99.56%,反射率低于0.01;在2.716~2.946 GHz频带内转换效率大于90%,S11小于-10 dB。实验中测试到的S11参数与模拟结果基本一致,证明了该变换器技术方案的可行性和模拟结果的正确性