衰减器

Based on fluid network theory ,the mathematical model of fluid pulsation attenuator was established.

采用流体网络理论方法对流体网络的特点和基本参数法进行分析，研究并建立一种流体脉动衰减器的数学模型，并通过脉动衰减器的阻抗及系统插入损失，对其性能进行研究。

They require well collimated light beam. For this, we introduced collimator. The collimator is used for collimating emanative Gaussian beam to obtain almost parallel beam with small emanative angle, or focusing parallel beam into fiber.

在光隔离器、光环形器、光开关、光衰减器、光波分复用器等光器件的工作过程中，对高斯光束的准直性要求非常高，这样就引入了光纤准直器。

An array of permalloy core solenoids is micromachined as microactuators on (100) silicon wafer. Then anisotropic etching of silicon in KOH solution forms the U-grooves beside the microactuators. The micromachining difficulties from the coexistence of 3-D MEMS devices and deep grooves on chip are overcome successfully. Then two fibers and permalloy piece are assembled onto the wafer together with the microstructures finishing the prototype of the new type MEMS VOA. Third, the inductance, resistance and Q value of the microfabricated solenoids are measured in the frequency range of 1-40 MHz.

第二，新开发了使用SU-85的正胶、负胶复合微加工工艺，在（100）硅片上加工了新型可变光衰减器的铁芯MEMS螺线管型电磁微执行器阵列；用KOH水溶液对（100）硅片进行湿法刻蚀，在电磁微执行器旁边微加工了V形槽结构组合，开发了单片集成三维MEMS器件和深槽的微加工关键技术；然后经过微装配制作出了电磁驱动的光纤偏移型MEMS可变光衰减器的样机。

7 To 3.3 V operating supply voltage 44.1 kHz sampling frequency 16.9344 MHz (384fs) system clock Built-in crystal oscillator circuit 16-bit, MSB rst, rear-packed serial data input format ( 64 fs bit clock) 8-times oversampling digital lter · 32 dB stopband attenuation ·+0.05 to -0.05 dB passband ripple Deemphasis lter operation · 36 dB stopband attenuation ·-0.09 to +0.23 dB deviation from ideal deem- phasis lter characteristics Attenuator · 7-bit attenuator (128 steps) set by microcontrol- ler Soft mute function set by parallel setting ·(approximately 1024/fs total muting time) Mono setting · Left or right channel mono selectable by micro- controller Built-in innity-zero detection circuit , two-channel D/A converter · 3rd-order noise shaper · 32fs oversampling Built-in 3rd-order post-converter low-pass lters 24-pin VSOP package Molybdenum-gate CMOS process

2.7至3.3 V工作电源电压为44.1千赫的采样频率16.9344兆赫（384fs）系统时钟内置晶体振荡器电路的16位，MSB在前，后包装的串行数据输入格式（64飞秒位时钟）8倍超采样数字滤波器·32分贝的阻带衰减·+0.05至-0.05分贝通带纹波去加重滤波器的运作·36 dB抑制频宽衰减·-0.09到0.23 dB的偏差认为不理想，症状困扰评估滤波特性衰减器·7位衰减器（128级）集由单片机在-莱尔软静音功能的平行设置·（共约1024/fs静音时间）单声道设置·左或右声道单声道微控制器可选的内置的无限零检测电路Δ，两通道的D / A转换器·第三阶噪声整形·32fs过采样内置三阶后转换器的低通滤波器24引脚VSOP封装钼栅CMOS工艺

In the dissertation, we presented a method to calculate the start oscillation length and real starting asynchronous velocity parameter. In the meantime, when the effect of two or more azimuthally asymmetric space harmonics in the high power broadband helix TWT on the start oscillation length and real starting asynchronous velocity parameter were also analyzed.

数值计算表明：增大渐变的强度，就可以增加起振长度，而且当渐变的强度增大到一定值时就不会产生返波振荡；当衰减器靠近输入段时，起振长度就随之减小；当增大衰减器的长度或减小衰减量时，相对起振电流随之减小，可见衰减器对起振条件确实有明显的影响。

Based on the theory of heat conduction, the heater thermal field was calculated to determine the most efficient position of heater. And the parameters of heater and asymmetric Y branch were decided using FD-BPM method. After the design and optimization, the polarization dependence and wavelength dependence of the attenuator were researched.

先根据前文介绍的热传导理论模拟了用于可调衰减器的电极的热场分布，设计了电极的最优位置，然后利用马卡蒂里近似解法求解掩埋条形波导的单模条件，并计算了波导的宽度和厚度，设计了非对称Y分支型的光衰减器的Y分支结构，电极参数，完成整个设计过程，最后，模拟了光衰减器的偏振相关性和波长相关性，从而也得到了一个聚合物可调光衰减器的设计优化方法。

The theories of cuneiform prism and series neutral glass slices used as laser attenuator are analyzed in this paper. An aberration-free laser quantitative attenuator made of cuneiform prism is adopted and a series of neutral attenuated slices are used for adjusting laser-beam enegy at the same time.

分析了楔形镜和中性玻璃衰减片组对光束的衰减原理，采用反射式楔形镜作为无像差定量衰减器，并同时使用中性玻璃衰减片组微调光束能量。

After theoretical analysis and magnetic architecture simulation, we designed external magnetic control units, while were assembled with optical isolators, to achieve the variable optical attenuators through electric control.

在衰减原理分析及磁力模拟后，设计出外置式磁力控制单元装设在光隔离器，以达成电控可调光衰减器的功能。

This paper introduces the method of eliminating noise with attenuator. Each end of the specimen is covered with a metal cap and attenuators are inserted between metal caps and load platens. so noise is reliably eliminated, true AE signals of rock are detected and the reliablity and the precision of the data are improved.

本文介绍的衰减器排噪法，采用试件两端粘接金属端帽，加载压板与端帽之间安装衰减器，从而可靠地排除了噪音，检测到了岩石试件真实的声发射信号，提高了检测数据的可靠性和精度。

The results show that this attenuator, which is 12mm×8mm×0.5mm and works at low temperature, can be used alone or integrated into HTS system to decrease system volume and weight. Insertion loss of this attenuator is about 0.2dB, whose magnitude is one order lower than that of a conventional attenuator. Attenuation step about 0.01dB can be achieved, which is 1~2 orders lower in magnitude than conventional attenuators.

主要结论如下：光控高温超导微波可变衰减器在液氮温区工作，电路尺寸为12mm×8mm×0.5mm，可单独使用也可集成于高温超导系统中，可大幅减小系统的体积与质量；高温超导衰减器的插损小于0.2dB，比常规衰减器低1个量级；高温超导衰减器的可变衰减步进值小于0.01dB，比常规衰减器低1~2个量级。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。