查询词典 single side band

This paper discussed the double sideband noise figures and single side band noise figures of the superheterodyne receivers in a ideal hypothesis and the practical case respectively.

分别讨论了在理想假设和实际情况下超外差接收机的双边带噪声系数和单边带噪声系数，给出了单边带接收机的某些设计方案。

One end of the band spins 120 degrees, takes three turns and connects with the other end, which forms a model of a single side curve of a trefoil knot.

由原来相互独立的三个面变为一个连通的闭和曲面。

With the support of a major research grant of Zhejiang Province (No. 001101027) and the Plan of Promoting Education of Excellence of Zhejiang University in the 21st Century, this dissertation is devoted to address the above problems and fabricate an L-band EDFA with low cost, high performance and technological innovation.First the mechanism of an erbium doped fiber amplifier is introduced. Various theoretical models based on classical rate propagation equations are summarized and compared for their applications. We use a modified numerical model based on the Giles model, which agrees with the experimental results well. This serves as the theoretical base for the whole thesis and will be used to optimize the characteristics of EDFAs. A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for EDFAs on the EDF length and the pump power. The characteristics of various EDFAs are studied and compared.Secondly, some important parameters are introduced to describe the characteristics of EDFAs. The methods and the experimental setups for measuring the gain and noise figure of an EDFA are emphasized. We introduce how to measure the characteristics of each component of an EDFA, especially the gain and absorption coefficient of an erbium doped fiber.Thirdly, four types of simple and novel L-band EDFA structures with low noise, high gain and low gain ripple are proposed to satisfy the requirement of a DWDM system. They can be classified into two categories. In the first category, a single ASE pumping is served asa secondary pump. This category includes the following three types. Type: a new construction using a fiber Bragg grating in an unpumped EDF section at the input side. Type: a new structure of L-Band EDFA with two-stage pumps, which utilizes the forward ASE as a second pump.

本论文本着科技创新、服务于生产实践的精神，以设计价格低廉，性能优越、结构合理简单的L-band EDFA为目标，依托浙江省科技厅重大科学基金资助项目(001101027)和浙江大学振兴教育计划资助的全光网络的搭建—《光通信技术》课程实验建设项目，展开了如下工作：首先，介绍了掺铒光纤放大器的工作原理，归纳总结了基于速率方程基础的EDFA的各种理论模型，分析比较了各个模型的特点和适用场合，最终选择完善的Giles理论模型作为本论文分析设计EDFA的理论基础；针对实际实验条件提出了修正的EDFA模型的数值计算方法；创新地提出了增益—噪声系数全局分析法，直观有效地分析了EDFA的增益和噪声系数与掺铒光纤长度和泵浦功率的依赖关系，并对各种EDFA的性能作了全面的比较；第二，介绍了掺铒光纤放大器特性参数的定义与测量方法，重点介绍了噪声系数和增益系数的测量方法及实验装置；介绍了组成掺铒光纤放大器各组件的特性测量方法，重点介绍了测量掺铒光纤参数的方法和实验装置；第三，针对WDM系统对L-band EDFA谱平坦、低噪声、高增益的要求，我们创新地提出了四种不同的L-band EDFA结构，按设计思路可以分为两大类：一类是基于单抽运二级泵浦法，这一类包括在未泵浦掺铒光纤的输入端插入一根布拉格光纤光栅的两段L-band的EDFA的新结构；基于前向ASE光作为二级泵浦源推动下一级EDF工作的泵浦分配、两段级联L-band的EDFA的新结构；基于单根光纤光栅、泵浦分配、两段级联的EDFA；另一类则是基于同时应用前后向C-band ASE作二级泵浦源的双抽运法，如基于前后向ASE光作为二级泵浦源的三段级联L-band的EDFA的新结构。

Common transparent quartz tube SiO2 more than 99.9% purity, geometry, chemical stability, thermal stability, resistance to thermal denaturation and anti-crystallization properties of the fine, optical transmittance above 93%; from hydroxyl in hydroxyl tube below 10ppm, after vacuum from hydroxyl, hydroxy-up to 5ppm below apply to high-pressure mercury lamp, sodium lamp, metal halide lamp, such as low-hydroxy products; white pipe, used mainly for heating tube, heating tube, far infrared control the manufacture, milky quartz pearl quartz tube possession of new technology, the management side as if the surface of pearls, all aspects of performance than ordinary white tube better; filter tube to filter out ultraviolet UV band in the harmful wavelengths of 190-320nm ultraviolet light source applied to environmental protection manufacturing; no ozone UV filter tube and pipe the contrary, through the ultraviolet wavelength around 253.7nm, there is no ozone UV lamp main material, widely used in medical equipment, water treatment, food hygiene, such as sterilization; quartz casing diameter 8-120mm in between, has a single opening, double opening round, flat-top shape and widen the mouth of necking, flanging, sanding and other processing, high temperature resistance, corrosion resistance, good light transmission and moisture-proof, explosion-proof characteristics such as widely used in aquarium thermostat, disinfection equipment, heating pipes, water treatment, metal halide lamp, such as product manufacturing and environmental protection, health, chemical and other fields; quartz Clamshell specifications 8-180mm, the shape according to the customer requirements, the bubble shell can take capillary has to carry out the exhaust, high temperature, light transmission is good, mainly for JC, JD, H1-H7, the stage lights and high-pressure mercury lamp, sodium lamp, metal halide lamp, such as product manufacturing; quartz water jacket mainly used in printing and packaging processing industry ---- UV light-curing, UV light curing is a very reliable and can be used to replace hot air dryers and other drying technique of curing technology, which in the printing and packaging of the processing industry has been widely.

普通透明石英管SiO2纯度达99.9%以上，几何尺寸、化学稳定性、热稳定性、抗热变性和抗析晶性能优良，光学透过率达93%以上；脱羟管羟基在10ppm以下，经过真空脱羟，羟基可达5ppm以下，适用于高压汞灯、钠灯、金卤灯等低羟基产品；乳白管，主要用于发热管、加热管、远红外管的制造，珠光石英管乳白石英管之新工艺，管面好象珍珠的表面，各方面性能比普通乳白管更优；滤紫外线管能够滤除紫外光谱波段中对人体有害的190-320nm波长的紫外线，适用于环保光源的制造；无臭氧管与滤紫外线管相反，可透过253.7nm左右波长的紫外线，是无臭氧紫外线杀菌灯的主要材料，广泛用于医疗器械、水处理、食品卫生等杀菌；石英套管直径范围在8-120mm之间，有单开口、双开口、圆头、平头等外形和扩口、缩口、翻边、磨砂等加工，具有耐高温、耐腐蚀、透光性好及防潮、防爆等特点，广泛使用于水族恒温器、消毒设备、加热管、水处理、金卤灯等产品的制造和环保、卫生、化工等领域；石英泡壳规格Φ8-180mm，形状根据客户要求，泡壳上可以接有毛细管，可进行排气，耐高温，透光性好，主要用于JC、JD、H1-H7、舞台灯和高压汞灯、钠灯、金卤灯等产品的制造；石英水套主要用于印刷和包装加工工业---- UV光固化， UV光固化是一种十分可靠的、可取代热空气干燥机和其他干燥技术的固化技术，它在印刷和包装加工工业已经得到广泛应用。

Utilizing an external modulator, we can up-converse vector signals without electrical mixer based on single side band with carrier suppression.

我们提出了一个新颖的全光升频直接侦测多级格式正交多频分工系统。

Double side band and/or single side band amplitude modulated citizens band radio equipment.

双边带和\或单边带调幅民用无线电频带设备。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。