传输损耗

Based on the characteristic equation of THz electromagnetic wave in metallic hollow waveguide, the dependence of the transformation attenuation and phase constant on the frequency of THz wave, inner radius of the waveguide and conductance of the metal material using Newton-Raphson iterative method.

从其传输的特性方程出发，利用Newton-Raphson迭代方法数值模拟了传输损耗和相位常数随太赫兹波频率、波导内径以及波导中金属镀层的电导率变化关系。

They consist of a coplanar wave-guide transmission line periodically loaded with 8 - 32 metal bridges, functioning as capacitive switches. Every switching element consists of a thin metallic membrane actuated by applied bias. Remarkable phase shifter performances were observed. 2 lAl0.96 Si0. 04 bridges MEMS Phase shifter reached to 372/3. 5mm under 20V bias at 35 GHz, the with an insertion loss (S21 of about 4 -7 dB...

该文介绍毫米波MEMS相移器的设计，研究低损耗衬底，Au，AlxSi1-x可动膜对下拉电压和传输损耗的影响，测试表明：21桥相位连续可调的分布式压控开关阵列一毫米波相移器在35GHz时，启动电压5V，20V时相移量达到372°/3.5 mm，并能在不同的控制电压下根据要求改变相移量。

Then the MEMS solenoid type electromagnetic actuating and novel, frictionless and wear-free, and simple structure are designed for fiber-deflecting type MEMS VOA: One of the two coupled single mode fibers is completely fastened in one of the three aligned U-shaped grooves while the deflectable fiber is partially fixed in another groove with a long front section suspending over the wider groove as a cantilever beam. The two fibers, any one for input and the other for output, are well aligned initially so that the insertion loss is very low. Beside the deflectable fiber is a solenoid microactuator with a U-shaped permalloy core attracting a permalloy piece glued on side of the fiber cantilever so that the fiber is deflected and the optical power coupled between the fibers decreased continuously. Using MEMS solenoid as a continuous actuator and the novel structure of VOA are not seen in literature.

为光纤偏移型MEMS可变光衰减器设计了MEMS螺线管电磁驱动方式以及新颖的避免了静摩擦、磨损而且简单的整体结构形式：在硅基片的三段V形槽结构中，将两个对接单模光纤之一完全固定在基片上，只将另一根光纤的稍后部位固定于基片上而使其前端的一定长度悬空，形成一个悬臂梁结构；初始对准后两根光纤之间的光传输损耗很小；通过U型铁芯MEMS螺线管吸引固定于光纤悬臂梁上的坡莫合金片，驱动光纤悬臂梁连续偏移以使两根光纤之间功率传输系数连续变化，从而达到光功率连续衰减的目的。

In guide switch of the present invention, the rotor and the stator are made to have conic frustums to constitute close contact for close fit, rather than loose fit, and this can eliminate spark during high-power microwave transmission, reduce the transmission loss caused by heating and reflection in the switch , and improve greatly the microwave transmission performance.

本发明通过把波导开关的转子和定子做成同锥度的锥形圆台面，使它们之间构成紧密接触，改动配合为紧配合，从而消除高功率微波传输时的打火现象，同时减小开关的传输损耗，减小开关的发热现象，降低反射，使微波传输性能大为改善，从而使这种开关能在高功率甚至超高功率微波系统中应用。

The characteristics of this copolyimide in chemistry and photics were determined.High quality copolyimide film could be obtained by casting the copolyimide solution on glass plate.Then the copolyimide was made into waveguide by using advanced processing techniques.Test results at optical co...

共聚物材料在溶液状态下用旋涂法获得了较高质量的共聚物薄膜，并在此基础上采用先进的光波导工艺技术将该材料制备成条波导，测试结果表明该波导在光通信波段1550nm处的平均传输损耗小于0.66dB/cm，局部损耗在0.2dB/cm，进一步改进后有望获得性能优异的光电子器件。

Based on the channel transmission theory,a complete and concise procedure for calculating the HF skywave's transmission loss is proposed in this paper by using and optimizing the available independent and disperse models reasonably.

根据信道传输理论，在合理选用和优化各种现有的独力分散数学模型的基础上，设计了一种完整而简洁的短波天波传输损耗计算流程，并针对流程中的每一步给出了详尽的数学模型。

The authors give the definition of insertion loss of electric locomotive in inductive communication through trolley wire in a mine tunnel and compute insertion loss and transmission loss. After contrasting the two losses, we know that the insertion loss is very large and it is necessary to use dedicated induction line.

给出了在矿井中利用电机车架空线进行感应通信时，架空线负载引起的插入损耗的定义，计算了插入损耗和无负载时的电磁波传输损耗并对比了这两种损耗，可知插入损耗是非常大的，这说明了使用专用感应线的必要性。

Based on the design of key aspects, the particle swarm optimization algorithm is used to design a flattened broadband transmission spectrum with transmission loss of nearly 50%.

根据设计中的关键技术，利用粒子群优化算法设计了长周期光纤光栅传输损耗为50％的平坦传输损耗谱。

The results of the simulation analysis and experiments indicate that the loss of ultraviolet scattering transmission in atmosphere is high because of the particle scattering and absorbing in solar-blind zone; that is, the received power can descend 20 dB with the distance increasing 10 times. Therefore, the ultraviolet scattering is fit for short range communication. In short range, the pulse extension due to scattering is at microsecond order and its influence for low and moderate bit rate communication systems is weak. Since the light output power of a single ultraviolet LED is low, a multi-LED array can be used to increase the transmit power and extend the communication range.

仿真分析与实验结果显示：日盲区紫外光在大气中散射传输时由于大气粒子的强烈散射与吸收，传输损耗较大，距离每增加10倍，接收功率下降20dB，因此日盲区紫外光大气散射通信适用于近距离通信场合；近距离传输时散射造成的光脉冲多径展宽为微秒量级，对中低速通信系统影响较小；单个紫外LED发光功率较低，可通过多个LED阵列来提高发射功率，增大通信距离。

The spectral characteristics of the device were measured by an optical spectrum analyzer in a set-up with fiber coupling. A periodically vibrated resonance spectrum was observed with 10 dB contrast and 0.182 nm period. According to the experimental data and the theoretical formula of the ring resonator, transmission loss of 1.7 dB/cm in the ring resonator was obtained.

利用光谱仪对器件的传输特性进行了测量，观测到具有10 dB对比度，自由光谱范围0.182 nm周期性谐振现象，结合环形谐振腔的传输特性，得到环形腔具有较低的传输损耗1.7 dB/cm。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了