基于光环形器的高增益L波段EDFA设计

设计了一种基于光环形器的双通结构L波段EDFA,并与单通结构的L波段EDFA做了比较,结果表明其增益较传统L波段EDFA提高了7dB,功率转换效率提高到27.29%。分析了接收端的噪声特性,并在原有结构基础上对放大器做了改进,使得信号增益提高了0.6dB,噪声系数至少降低了0.3dB。     

C波段GaAs单片低噪声放大器

本文介绍了C波段GaAs微波单片集成低噪声放大器的设计,给出了电路拓扑与版图设计.在3.7～4.2GHz下,研制成的两级放大器噪声系数为1～3.5dB,增益为20dB左右;三级放大器噪声系数为1.6～3.5dB,增益大于30dB.     

Ka波段低噪声放大器的设计

利用pHEMT工艺设计了一个Ka波段微波单片低噪声放大器电路。电路采用四级放大的结构形式。利用微带电路实现射频输入、输出和级间匹配。采用多目标优化方法对电路增益、噪声系数、驻波比、稳定系数和输出1dB压缩点等特性进行了研究。设计出一个增益大于20dB,噪声系数小于1．0dB,1dB压缩点的输出功率在10dBm以上,性能优异的LNA。     

L波段载板式双平衡限幅低噪声放大器北大核心CSCD

设计了L波段PIN限幅器芯片和低噪声放大器芯片,并将这两种芯片集成在载板上,组成小尺寸双平衡限幅低噪声放大器。低噪声放大器采用负反馈结构,降低噪声系数和改善增益平坦度。采用双平衡式结构,提高限幅器的功率容量,提高了1dB增益压缩点输出功率。对传统兰格桥结构作了改进,缩小了电路面积。该限幅低噪声放大器工作电压5V,电流40mA。测试结果显示,在频带1.2~1.4GHz内,噪声系数小于1.2dB,增益大于28dB,P1dB大于6dBm,能够承受脉冲功率150 W(脉宽200μs和占空比为20%)。体积为7.5mm×5.0mm×0.9mm。     

高增益低噪声L波段掺铒光纤放大器实验研究

针对L波段掺铒光纤放大器(EDFA)增益低、噪声大的缺点,提出了L 波段双级级联双程放大的放大器结构,并对优化设计结果进行了实验验证。实验中前级和后级所用的铒纤长度分别为6.5m 和32.5m,泵浦功率分别为130mW 和119mW。在小信号功率(-30dBm)输入条件下、1568～1602nm 波长范围内,放大器输出增益都大于38.84dB 同时增益平坦度优于2.04dB。其噪声指数在整个L 波段都小于5.29dB(1590nm 处噪声指数仅为3.95dB)。实验结果表明此放大器不仅完全满足预放级放大器高增益、低噪声的要求,而且具有成本低、泵浦效率高的优点。     

级连L波段EDFA优化的数值模拟与实验

对级连结构的L波段EDFA进行了优化设计.首先用加拿大Optiwave的OptiAmplifier4.0数值模拟了在其他条件确定情况下两级光纤长度比例变化对放大器性能的影响,在优化光纤长度比例的基础上,为了得到更宽的L-EDFA的本征平坦增益谱,进一步优化了前后级泵浦功率.在上述条件下利用42 m的铒纤得到实验结果为:ASE谱3 dB带宽1566.84～1606.80 nm(40 nm).在L波段(1570～1605 nm),小信号平均增益约为25 dB,增益不平坦度为±1 dB,噪声指数约为5 dB.     

铋镓铝共掺的高浓度掺铒光纤及放大器

研制出了铋镓铝共掺的高浓度掺铒光纤,这种掺铒光纤在1 530 nm处的吸收系数达到了28.5 dB/m.利用这种铋镓铝共掺的高浓度掺铒光纤制成了C波段和L波段的掺铒光纤放大器(EDFA),测试这两种放大器的荧光谱和增益谱线.利用2.5 m的高浓度掺铒光纤制作的C波段EDFA就实现了高增益.利用10 m这种掺铒光纤制作的L波段放大器实现了有效的I波段放大.     

57nm的低噪声宽带掺铒光纤放大器

采用双级级联单程放大实现高增益、低噪声的C波段掺铒光纤放大器(EDFA)；采用双级级联双程放大实现高增益、超平坦的L波段EDFA。在此基础上，采用并联结构实现了30dB以上的高增益、3dB带宽为57nm的低噪声宽带EDFA。     

C+L波段宽带增益平坦铋基掺铒光纤放大器的设计

基于光纤放大器增益谱的宽带平坦化发展需要,设计了一个两段铋基掺铒光纤(Bi-EDF)级联并携带一个C波段(1 530~1 565 nm)宽带光纤布拉格光栅(FBG)的双通结构型铋基掺铒光纤放大器(Bi-EDFA),从理论上研究了其对输入信号的放大特性。研究表明:FBG的引入可以使C和L波段(1 570~1 620 nm)信号分别经历不同长度Bi-EDF的双向传输,各自获得高增益放大,实现增益谱的宽带平坦化。在200 mW的1 480 nm双向对称泵浦下,第一级和第二级Bi-EDF长度分别为50 cm和170 cm时,对于波长间隔为2 nm、每路功率为-30 dBm的56路C+L波段信号的输入,Bi-EDFA高于30 dB的增益带宽达到了90 nm(1 530~1 620 nm),平均增益为35.7 dB,增益起伏仅为2.3 dB。同时,噪声系数得到明显改善。研究结果对于研制具有宽带、增益平坦的C+L波段Bi-EDFA具有实际指导意义。     

S波段低噪声放大器仿真设计

介绍了S波段低噪声放大器(LNA)的设计原理,分析了影响放大器稳定性、噪声系数、功率传输的主要因素,运用Agilent公司的EDA软件ADS仿真设计了两级级联结构的放大器。仿真结果表明放大器在2150～2 400MHz的频率范围内,噪声系数<0.5dB,输入驻波比<1.4,输出驻波比<1.14,增益为(26.2±0.5)dB,并且在全频带内无条件稳定。     

Improvement of gain and noise figure in double-pass L-band EDFA by incorporating a fiber Bragg grating

An obvious improvement on both the gain and noise figure (NF) is demonstrated in the new double-pass L-band erbium-doped fiber amplifier (EDFA) with incorporating a fiber Bragg grating (FBG). Compared with the conventional L-band EDFAs, the gain is improved by about 6 dB in the new configuration for a 1580-nm signal with an input power of -30 dBm at 60 mW of 980-nm pump power. It is important that the NF is greatly reduced in the new configuration, as the FBG greatly compresses the backward amplified spontaneous emission. For the economical utility of pump power and erbium-doped fiber length, such a configuration may be a very competitive candidate in the practical applications of L-band EDFAs.     

Gain clamping in two-stage L-band EDFA using a broadband FBG

A gain-clamped long wavelength band erbium-doped fiber amplifier (L-band EDFA) with an improved gain characteristic is demonstrated by simply adding a broadband conventional band (C-band) fiber Bragg grating (FBG) in a two-stage amplifier system. The FBG reflects backward C-band amplified spontaneous emission (ASE) from the second stage back into the system to clamp the gain. The gain is clamped at about 22.4 dB with a gain variation below 0.4 dB for input signal powers of -40 to -15 dBm. Compared with an unclamped amplifier of similar noise figure values, the small signal gain has improved by 2.4 dB due to the FBG which blocks the backward propagating ASE. At wavelengths from 1570 to 1600 nm, gain of the clamped amplifier varies from 19.4 to 26.7 dB. The corresponding noise figure varies by /spl plusmn/0.35 dB around 5 dB, which is not much different compared to that of the unclamped amplifier.     

Optimum pumping configuration for L-band EDFA incorporating ASE pump source

L-band gain improvement through usage of secondary pumping sources in the form of amplified spontaneous emission (ASE) was conducted. A simulation of the three-level rate equation that precedes the experimental approach provides a limited overview of the behavior of various inputs into the active medium-the erbium-doped fiber. Gain improvement as high as 6 dB was attained while incurring minimal noise figure penalty; in this case as low as 1 dB. For an L-band amplifier system employing ASE to improve gain, pumping the system counterdirectionally with ASE while the 980- or 1480-nm pumps are being used in a copropagating configuration would yield the best overall performance in terms of gain.     

A low-noise L-band EDFA with a 1500-nm Raman-pumped dispersion-compensating fiber section

This report presents a low-noise L-band erbium-doped fiber amplifier (EDFA) with a dispersion-compensating Raman amplifier. With an optimized prestage and 1500-nm Raman-pump laser diodes, the proposed EDFA achieved an internal noise figure of less than 4.5 dB over a 33-nm flat gain bandwidth within 0.5 dB at -2 dBm of large signal input power.     

Low-noise intelligent cladding-pumped L-band EDFA

We present results on a low-cost cladding-pumped L-band amplifier based on side pumping (GTWave) fiber technology and pumped by a single 980-nm multimode diode. We show that simultaneous noise reduction and transient suppression can be achieved by using gain clamping by a seed signal (/spl lambda/=1564 nm). In the gain-clamping regime, the amplifier exhibits 30-dB gain over 1570-1605-nm spectral band with noise figure below 7 dB. The noise figure can be further reduced to below 5 dB by utilizing a low power single-mode pump at 980 nm. The erbium-doped fiber amplifier is relatively insensitive to input signal variations with power excursions below 0.15 dB for a 10-dB channel add-drop.     

Coupled structure for wide-band EDFA with gain and noise figureimprovements from C to L-band ASE injection

We propose a novel structure for C plus L-band silica based wide-band erbium-doped fiber amplifiers (W-EDFA's), which use backward amplified spontaneous emission from the C-band EDFA as the pump-mediating injection source for the L-band amplifier unit. Experimental results show gain and noise figure improvements of over 2.6 dB and 0.6 dB, respectively, at -3.5 dBm of L-band input signal power. Spatially resolved numerical analysis confirms the pump-mediating effect of C-band backward ASE in the L-band EDFA for the gain and noise figure improvement, which also provides better understanding on the dynamics of C-band injection seed methods     

Broad-band erbium-doped fiber amplifier with double-passconfiguration

We demonstrate a broad-band silica-based erbium-doped fiber amplifier (EDFA) with double-pass configuration. The signal gain and noise figure are obtained more than 24 dB and less than 6 dB, respectively, for 1526-1562 nm and 1569-1605 nm. The same signal gain can be achieved with 53% less pump power and 45% shorter erbium-doped fiber length, compared to a conventional parallel type EDFA. Furthermore, the noise figure and power conversion efficiency are improved for the wavelength range     

Low-power-consumption and high-gain CMOS distributed amplifiers using cascade of inductively coupled common-source gain cells for UWB systems

A distributed amplifier with new cascade inductively coupled common-source gain-cell configuration is presented. Compared with other existing gain-cell configurations, the proposed cascade common-source gain cell can provide much higher transconductance and, hence, gain. The new distributed amplifier using the proposed gain-cell configuration, fabricated via a TSMC 0.18-/spl mu/m CMOS process, achieves an average power gain of around 10 dB, input match of less than -20 dB, and noise figure of 3.3-6.1 dB with a power consumption of only 19.6 mW over the entire ultra-wideband (UWB) band of 3.1-10.6 GHz. This is the lowest power consumption ever reported for fabricated CMOS distributed amplifiers operating over the whole UWB band. In the high-gain operating mode that consumes 100 mW, the new CMOS distributed amplifier provides an unprecedented power gain of 16 dB with 3.2-6-dB noise figure over the UWB range.     

L波段砷化镓单片低噪声放大器

设计、研制了一种工作在Ｌ波段的ＧａＡｓ单片低噪声放大器。该放大器在ＨＰ－８５１０Ｂ网络分析仪和ＨＰ－８９７０Ｂ自动噪声仪上的测试结果为：１．１～１．５ＧＨＺ频段，ＮＦ≤２．０ｄＢ，Ｇ≥１８ｄＢ，ＶＳＷＲ（ｉｎ，ｏｕｔ）≤２：１，增益起伏≤０．５ｄＢ；在１．５～２．０ＧＨＺ频段ＮＦ≤２．５ｄＢ，Ｇ≥１８ｄＢ，ＶＳＷＲ（ｉｎ，ｏｕｔ）≤２：１，增益起伏≤±０．５ｄＢ。