放大器

The MRI system consist of magnetic, spectrometer, RF amplifier, gradient amplifier, computer systems, etc .

磁共振成像系统是由磁体、谱仪、射频放大器、梯度放大器和计算机系统等组成。

This article is intended to discuss the principle and characteristic of a magnetic amplifier ,introduce the action of the magnetic amplifier in the actuator and analyse some troubles of the actuator.

论述了磁放大器的工作原理和特点，介绍了磁放大器在执行器中的应用，对执行器的两种常见故障作了分

According to the characteristic of the wiggler magnetic field in this amplifier, proper magnetic field input method is chosen in the process of PIC simulated research.

针对该放大器中摇摆器磁场的特点，选择了适当的磁场输入形式，顺利实现了对该结构摇摆器自由电子激光放大器的粒子模拟研究。

In the electronic system, a power amplifier which provides magnetic coil with exciting current to produce electromagnetic force is one of the main components. General commercialization of power amplifiers can not meet the application requirements, but should be designed.Power amplifiers are divided into linear amplifier and switching amplifier.

磁悬浮轴承是典型的机电一体化系统，在其电控系统(传感器、控制器和功率放大器)中，功率放大器具有重要的作用，它向电磁铁线圈提供相应的控制电流以产生所需要的电磁力。

Switching power amplifier of magnetic bearing worked in hard switching. To overcome drawbacks of large loss of switching and current harmonic distortion, a parallel resonant DC link soft-switching power amplifier was adopted in this paper.

为克服磁悬浮轴承开关功率放大器工作在硬开关状态时存在的开关损耗和电流纹波干扰严重的缺点，提出一种磁悬浮轴承并联谐振直流环节的软开关功率放大器电路。

Three magnetic amplifier s, such as adjustable-damper controlling, speed-limited protection in deceleration segment, and automatic braking largely used in alternated-elevator system in nation's coal and metallurgy exhibit quickness and firmness.

我国煤炭和冶金矿山大量使用的交流提升机，控制系统采用的可调闸控制、减速段限速保护和减速阶段电气制动三个磁放大器装置，存在快速性、稳定性、对环境参数的依赖性、敏感性均较差等固有弊端，采用现代电子器件和先进的控制技术取代原控制系统中的1CF、2CF、 3CF三个磁放大器及其落后的控制技术，并增加全新的电子速度给定环节，改善提升机性能

Parametric amplifier in a number of microwave devices, widely used, usually in radar, navigation, electronic warfare, radio astronomy microwave systems such as receiver front-end amplifier, greatly increased the sensitivity of the receiver.

参量放大器在许多微波设备中得到广泛的应用，通常在雷达、导航、电子对抗、射电天文等微波系统中作接收机前端放大器，大大提高了接收机的灵敏度。

Especially , with the wide use of the low noise microwave receiver model of "low noise amplifier - mixer - intermediate frequency amplifier", the rejection to image frequency interference has become the last problem how to make the whole receivers noise low and resist interference.

尤其是随着"低噪声放大器——混频器——中频放大器"这种低噪声微波接收机模型的广泛使用，对镜频干扰的抑制已逐渐成为整机低噪声、抗干扰的最后难题。

In the measure amplification circuit, direct-current or low frequency signal come from a common sensor , conveying in only rhyme fashion way after amplification, In typical situation, serviceable signal maximum amplitude probable only have a certain number or amount millivolt, but common mode noise suppression may be up to several volt, as a result it is significant to the factor of the amplification input drift and noise etc for total precision, the amplification in itself common mode restraints features is also equally binding problem.

在测量用的放大电路中，一般传感器送来的直流或低频信号，经放大后用单端方式传输，在典型情况下，有用信号的最大幅度可能仅有若干毫伏，而共模噪音可能高到几伏，故放大器输入漂移和噪声等因素对于总的精度至关重要，放大器本身的共模抑制特性也是同等重要的问题。

In the method of the invention, a baseband signal is pre-processed to realize nonlinearity compensation. The pre-processing method comprises the following steps: the filter coefficient and the multinomial coefficient of the high power amplifier are extracted; corresponding gain is calculated for the amplitude value of each point input into the sequence of the baseband signal, and the phase compensation value is calculated according to the amplitude gain; the phase compensation value and the gain which are corresponding to each point are synthesized into re-gain, a pre-processing value pi is obtained, and pre-processing output sequence is formed; the pre-processing output sequence is output into the high power amplifier directly or through a inverse filter.

本发明方法是将基带信号进行预处理来实现抵偿非线性，预处理方法是：提取出高功率放大器的滤波器系数和多项式系数；对输入基带信号序列中的每一点的幅值计算对应的增益，根据幅度增益计算出相位补偿值；每一个点对应的相位补偿值与增益合成复增益，得到预处理值p i ，构成了预处理输出序列；将预处理输出序列直接或经过反向滤波器后输出到高功率放大器中。

Methods: Five patients with parkinsonism or dystonia were assigned to general anesthesia using an modified endotracheal tube.

本实验依照人体实验之相关规定进行，五位患有帕金森氏症或肌张力异常的病人接受神经立体定位手术。

If you can benefit from this book, it is our honour.

如果您能从本书获益，这将是我们的荣幸。