共查询到20条相似文献,搜索用时 23 毫秒
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本文提出了掺饵光纤放大器(EDFA)增益的精确模型,并对EDFA的增益进行了计算,其结果与实验相当符合。并在此基础上,结合光子数的Master方程和Personick关于接收机的理论,详细地分析了当EDFA为前放、中断时,其增益与接收机的噪声以及灵敏度在一定误码率下的关系。 相似文献
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Erbium-doped fiber amplifiers (EDFAs) with high gain generally degrade the signal-to-noise ratio by at least 3 dB. In the conventional wavelength band, noise figures close to the so-called quantum limit can be obtained by strong pumping. Due to their lower average population in the metastable level, this limit is not reached by amplifiers designed for the long-wavelength band (L-band). In this paper, the lower noise figure limit is determined for such amplifiers. It has been found that the noise figure for typical gain values of about 30 dB can be very close to the quantum limit, whereas significantly larger noise figure values result for small amplifier gains. The lower limit decreases with increasing gain if the gain values are beyond 5 dB. In addition, the results reveal that low temperatures yield better noise figure. 相似文献
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主要介绍了C波段高增益低噪声单片放大器的设计方法和电路研制结果。电路设计基于Agilent ADS微波设计环境,采用GaAs PHEMT工艺技术实现。为了消除C波段低噪声放大器设计中在低频端产生的振荡,提出了在第三级PHEMT管的栅极和地之间放置RLC并联再串联电阻吸收网络的方法,降低了带外低频端的高增益,从而消除了多级级联低噪声放大器电路中由于低频端增益过高产生的振荡。通过电路设计与版图电磁验证相结合的方法,使本产品一次设计成功。本单片采用三级放大,工作频率为5~6GHz,噪声系数小于1.15dB,增益大于40dB,输入输出驻波比小于1.4∶1,增益平坦度ΔGp≤±0.2dB,1dB压缩点P-1≥10dBm,直流电流小于90mA。 相似文献
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Belloui Bouzid 《中国电子科技》2010,8(1):74-77
A comprehensive behavioral investigation of gain and noise figure(NF) at different erbium doped fiber amplifier(EDFA) configurations is proposed.Configurations such as single pass(SP),single pass with filter(SPF),double pass(DP) and double pass with filter(DPF) are designed,investigated and compared.A continuous increasing of gain value is recorded by changing the configuration from SP to SPF to DP then to DPF.The NF value shows different behaviors at different configurations. 相似文献
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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。 相似文献
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Numerical Analysis of Gain Saturation, Noise Figure, and Carrier Distribution for Quantum-Dot Semiconductor-Optical Amplifiers 总被引:1,自引:0,他引:1
Jin-Long Xiao Yong-Zhen Huang 《Quantum Electronics, IEEE Journal of》2008,44(5):448-455
The gain saturation behaviors and noise figure are numerically analyzed for quantum-dot semiconductor optical amplifiers (QD-SOAs). The carrier and photon distributions in the longitudinal direction as well as the photon energy dependent facet reflectivity are accounted in the rate equations, which are solved with output amplified spontaneous emission spectrum as iterative variables. The longitudinal distributions of the occupation probabilities and spectral-hole burning are presented for electrons in the excited and ground states of quantum dots. The saturation output power 19.7 dBm and device gain 20.6 dB are obtained for a QD-SOA with the cavity length of 6 mm at the bias current of 500 mA. The influences of the electron intradot relaxation time and the QD capture time on the gain spectrum are simulated with the relaxation time of 1, 30, and 60 ps and capture time of 1, 5, and 10 ps. The noise figure as low as 3.5 dB is expected due to the strong polarization sensitive spontaneous emission. The characteristics of gain saturation and noise figure versus input signal power for QD-SOAs are similar to that of semiconductor linear optical amplifiers with gain clamping by vertical laser fields. 相似文献
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In this paper, we investigate the effects of complex energy transfer dynamics and Gaussian profiles on the gain and noise figure performance of erbium-doped fiber amplifiers (EDFAs) with high doping concentration. We use a two-level system to study the complex energy transfer dynamics that comes from the homogeneous up-conversion (HUC) and the pair-induced quenching (PIQ). In our model, the system is stimulated by a pump source at the wavelength of 1480 nm and operated with a signal source at the wavelength of 1560 nm. Assuming a uniform distribution of erbium ions in the fiber core, we approximate the fundamental mode distributions by Gaussian profiles which are commonly used to calculate the mode radius or spot size. Using the numerical calculations and analysis of the rate and power propagation equations for a two-level model under consideration, the most advantageous Gaussian profile is determined as the Whitley mode radius to obtain a high-gain and a low-noise figure per unit length of silica-based fiber amplifiers. The effects of the number of ions per cluster and the percentage of ions in clusters on the calculated gain and noise figure are compared for several pump powers. Results are discussed to achieve a desired gain and noise figure performance, and compared with the available experimental data to verify the feasibility of the model. 相似文献
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《Microwave Theory and Techniques》1985,33(3):233-242
The upconversion of Iow-frequency noise in microwave FET oscillators is investigated. The theoretical analysis is presented in two forms, a general and a simplified one. The latter version yields closed-form expressions for amplitude and phase noise, which are discussed wfth regard to the physics of the upconversion process. Application of the method is demonstrated with an example. 相似文献
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报道了一种基于商用0.15um赝配高电子迁移率晶体管工艺的单片低噪声放大器,工作频率范围为23~36GHz.它采用自偏置结构.对晶体管栅宽进行了优化设计减小栅极电阻,以得到低的噪声系数.采用吸收回路和加电阻电容网络的直流偏置结构提高电路稳定性,用多谐振点方法和负反馈技术扩展带宽.测试结果表明,其噪声系数低于2.0dB,在31GHz处,噪声系数仅为1.6dB.在整个工作频带范崮内,增益大于26dB,输入回波损耗大于11dB,输出回波损耗大于13dB.36GHz处的ldB压缩点输出功率为14dBm.芯片尺寸为2.4mm×1mm. 相似文献
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2dB噪声系数的Ka波段宽带高增益单片低噪声放大器 总被引:1,自引:1,他引:0
报道了一种基于商用0.15um赝配高电子迁移率晶体管工艺的单片低噪声放大器,工作频率范围为23~36GHz.它采用自偏置结构.对晶体管栅宽进行了优化设计减小栅极电阻,以得到低的噪声系数.采用吸收回路和加电阻电容网络的直流偏置结构提高电路稳定性,用多谐振点方法和负反馈技术扩展带宽.测试结果表明,其噪声系数低于2.0dB,在31GHz处,噪声系数仅为1.6dB.在整个工作频带范崮内,增益大于26dB,输入回波损耗大于11dB,输出回波损耗大于13dB.36GHz处的ldB压缩点输出功率为14dBm.芯片尺寸为2.4mm×1mm. 相似文献
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两路合成式LNA的噪声系数分析与设计 总被引:1,自引:0,他引:1
两路合成式接收系统的噪声系数对各路增益的一致性要求很高.为保证测试和实际使用中噪声系数误差控制在合理范围内,结合理论计算和ADS软件仿真,得出两路增益差控制在±5%左右,噪声系数误差在±0.1dB左右.将此结论应用于工程设计中,取得了较好的效果. 相似文献
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A 3.1-10.6 GHz ultra-wideband two-stage pseudomorphit high electron mobility transistor low noise amplifier is presented. The first stage of the amplifier employs a resistive shunt feedback topology and two T-network sections to provide wideband input matching to a 50-Omega antenna. The current-sharing dc bias topology is used to ensure the low power consumption under fixed 3-V battery operation. The amplifier exhibits state of the art performance consuming only 12.9mW of dc power with a power gain of 12.5dB, plusmn0.5dB gain flatness, and 3.4-4.0dB noise figure. Input match is better than -12.0dB, output match is better than -15dB, and group delay is 184pSplusmn28pS 相似文献
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微波光链路的噪声系数分析 总被引:1,自引:0,他引:1
微波光链路(MPL)是利用光纤传输微波信号,与传统的射频链路相比具有带宽大、损耗小、质量轻、抗电磁干扰等优势,但也存在噪声系数较大的问题,从而影响链路的动态范围.建立了直接调制的微波光链路模型,在不考虑频响的情况下推导出链路固有增益和噪声系数的表达式,研究了激光器的转换效率、光纤的损耗和相对强度噪声(RIN)对链路噪声系数的影响.还建立了链路频响的模型,推导出固有增益与频率关系的表达式,分析仿真了频率对链路固有增益和噪声系数的影响,并与实验结果进行了比较. 相似文献
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Jehyung Yoon Huijung Kim Changjoon Park Jinho Yang Hyejeong Song Sekyeong Lee Bumman Kim 《Microwave Theory and Techniques》2008,56(3):626-631
The noise figure of an RF CMOS mixer is strongly affected by flicker noise. The noise figure can be improved using pMOS switch circuits, which insert current at the on/off crossing instants of the local oscillator switch stage because the circuits reduce the flicker noise injection. When it is applied to a conventional Gilbert mixer, the injection efficiency and linearity are degraded by the nonlinear parasitic capacitances of the pMOS switch circuits and the leakage through the parasitic path. We propose the pMOS switch circuits with an inductor, which tunes out the parasitic components at 2fo and closes out the leakage path. The mixer fabricated in 0.13-mum CMOS at 2.4-GHz center frequency has provided improved characteristics for linearity and noise figure. 相似文献
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噪声系数测量中误差分析和不确定度的评定 总被引:1,自引:0,他引:1
噪声系数是评估电子装备的关键参数之一,噪声系数的高低决定着接收机的性能.介绍了噪声系数的测量方法,分析了在实际测试过程中所有可能的测量误差来源以及可以避免或减小的方法.由于不可避免的测量误差引入了测量不确定度,因此给出了噪声系数测量结果的不确定度的评定方法.噪声系数测量的不确定度与被测件的噪声系数及增益关系密切,针对本测试系统,计算出测试结果不确定度的范围为0.41~0.63 dB.本研究对提高任何频段噪声系数测试结果的准确度具有参考意义. 相似文献
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Transmitting optical bursts through a chain of erbium-doped fiber amplifiers (EDFAs) results in dynamic gain changes, which in turn lead to possibly large variations in output power of the data channels. There are many proposals how to control these optical amplifiers in order to minimize or eliminate the power variations. In this paper, we investigate the gain dynamics in a burst switching environment experimentally and numerically. With a categorization of gain control schemes we review the state of the art and discuss advantages and disadvantages of the different approaches particularly with regard to burst switching networks. A comparison of the performance of these methods is given. In our opinion there are two preferences, one for the scheme using electronic feedback on the EDFA's pump power, because of good performance, and another for schemes controlling whole links of EDFA cascades by an extra control channel, because of lower costs. 相似文献