共查询到20条相似文献,搜索用时 15 毫秒
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在相同条件下(如抽运光功率、信号光功率等),与单抽运相比,双抽运光参量放大(OPA)的增益大,增益带宽宽.由于信号光的增益特性与参量增益系数直接相关,因此,在建立高非线性光纤(HNLF)光参量放大的理论模型的基础上,对相位匹配条件、参量增益以及信号光饱和增益的特性进行了分析讨论,采用有限差分法,对增益饱和的特性进行了模拟.结果表明,参量增益和光纤参数、输入抽运光以及信号光的波长、功率有关,而信号光的饱和增益和输入抽运功率有关. 相似文献
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《Circuits and Systems Magazine, IEEE》2008,8(1):55-71
Introductory treatments of feedback amplifiers commonly contain inconsistencies, or present results as universal when in fact they need qualification. Loop gain, overall gain, input impedance and output impedance are instances. A case can therefore be made for rigorous development, even in a first course, provided mathematical rigor can be combined with physical insight. A feedback factor H is first defined for ideal circumstances. The corresponding forward-path gain G has an obvious physical interpretation: the amplifier without feedback, the external source and load impedances, and the feedback network are all involved, and the form of G is such as to suggest best practice for the various feedback configurations. Stability considerations, and precise values for overall gain, sensitivity, input impedance and output impedance follow directly from GH. 相似文献
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We describe a general offset-canceling architecture for analog multiplication using chopper stabilization. Chopping is used to modulate the offset away from the output signal where it can be easily filtered out, providing continuous offset reduction which is insensitive to drift. Both square wave chopping and chopping with orthogonal spreading codes are tested and shown to reduce the offset down to the microvolt level. In addition, we apply the nested chopping technique to an analog multiplier which employs two levels of chopping to reduce the offset even further. We discuss the limits on the performance of the various chopping methods in detail, and present a detailed analysis of the residual offset due to charge injection spikes. An illustrative CMOS prototype in a 0.18 mum process is presented which achieves a worst-case offset of 1.5 muV. This is the lowest measured offset reported in the DC analog multiplier literature by a margin of two orders of magnitude. The prototype multiplier is also tested with AC inputs as a squarer, variable gain amplifier, and direct-conversion mixer, demonstrating that chopper stabilization is effective for both DC and AC multiplication. The AC measurements show that chopping removes not only offset, but also 1/f noise and second-order harmonic distortion. 相似文献
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研究输入信号功率对掺铒光纤放大器(EDFA)增益斜率的影响,可为EDFA的优化设计提供理论参考.采用了实验分析和数值模拟两种方法,在EDF长度为14 m,输入波长为1530~1562 nm,泵浦光功率为400mW时,对输入信号功率为-5~5 dBm的EDFA增益斜率进行了对比,发现随着输入信号功率的增大,增益斜率也逐渐... 相似文献
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《Microwave Theory and Techniques》1977,25(7):621-622
lnterdependence of gain and idler conversion has been experimentally investigated in parametric amplifiers having, single diode circuit configuration. The results indicate that for high gain amplifiers, the inherent idler rejection is inadequate, and larger lengths of pump waveguide, designed to be below cutoff at idler frequency, are to be used for reducing the effect of pump sideband noise on the noise temperature of the parametric amplifiers. 相似文献
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Iboun Taimiya Sylla Mustapha Slamani Bozena Kaminska 《Journal of Electronic Testing》2001,17(1):53-61
The availability of faster electronic components allows the design of more effective and efficient test equipments. However in high-speed applications, the effect of interconnects between the tester and the device under test DUT introduces ringing, overshoot and timing delay problems. In this paper we present an output high speed buffer which helps to cancel the overshoot, undershoot, and ringing. The buffer which has a unity gain, presents a high output current and introduces small delay. It is able to drive the comparator of the tester through the transmission line with minimum distortion of the signal. Compared with other approaches, the use of this output buffer provides good improvement of the signal. This output buffer which is designed for the interface between tester and DUT can be considered for communication between high speed devices in printed circuits boards. The calibration procedure is explained in order to determine the delay introduced by the buffer and to measure low and high voltage levels of the digital output signal of the buffer. 相似文献
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神光Ⅱ装置精密化功率平衡要求8路子光束的输出能量平衡和脉冲波形一致,即每条放大链的增益和透过率相同。但装置因日常打靶工作需要,8路子光束放大链中同级放大器的增益能力差异较大。针对该问题,利用一种精度优于1%的小能量测量系统,对神光Ⅱ装置8路四级放大器的小信号增益进行在线测量,分别得到了40,70棒状放大器,100片状放大器和200双层片状放大器在正常工作电压下的小信号增益值,掌握了每路各级放大器的增益特性,精确量化了各路同级放大器的差异,为神光Ⅱ精密化功率平衡调试提供了宝贵的实验数据。 相似文献
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正确使用集成运算放大器必须了解影响其工作性能的主要,其中输入误差信号是影响运放工作性能的重要参数之一。本文主要研究引起集成运放输入误差信号的主要参数及减小其影响的方法。 相似文献
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为了深入研究量子点半导体光放大器(QD-SOA)的特性,建立了量子点半导体光放大器子带导带的三能级系统模型.把系统载流子的速率方程与其他文献采用的速率方程进行了对比优化.通过数值计算得到了瞬态解,并得到载流子在放大器各能级态的浓度分布,验证了量子点中能级分立特性.利用电子和空穴各自的占有几率在基态成一定的线性关系,在稳态下对速率方程求解,得出了量子点半导体光放大器相关的增益特性,以及增益特性与基态电子的占有几率之间的关系.结果表明量子点半导体光放大器具有很高的饱和增益和微分增益,较低的阈值电流等特性.说明量子点半导体光放大器具有比其他体材料和量子阱光放大器更加优异的特性.为光放大器的设计提供了有力的理论指导. 相似文献
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利用自由电子激光中电子与辐射波多次相互作用原理,获得了大信号情况下自由电子激光增益表达式。结果表明,大信号增益公式可圆满地解释自由电子激光器实验中激光输出饱和现象。 相似文献
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