查询词典 frequency modulation

Pulse, Amplitude and Frequency modulation are all available.

脉冲，幅度和频率调制都可用。

The frequency of the amplitude modulation signal is adjusted until a maximum lamp voltage is detected.

调节调幅信号的频率，直至检测到最大的灯电压为止。

Not only it is expediently to realize frequency, phase and amplitude modulation, but also it has well practicability.

采用FPGA设计的信号发生器，不仅可方便地实现各种比较复杂的调频、调相和调幅功能，而且具有良好的实用性。

Reflection wave have the action of amplitude and frequency modulation.

反射波具有振幅调谐和频率调谐作用。

Spectrum control technology and its application researchBasic theory of smoothing by spectral dispersion in high-power laser system was studied. Periodical frequency modulation was obtained by chirped pulse stacking, and novel special gratings were proposed here to obtain angular spectral dispersion and temporal smoothing of focal spot.

并在国际上首次成功地应用于激光聚变高功率激光系统中。3、激光脉冲光谱控制技术及应用研究研究了高功率激光光谱色散平滑的基本理论，提出利用堆积啁啾脉冲的周期性光谱调制特性和新颖特殊光栅实现光谱角色散和激光束远场焦斑的时间平滑。

Based on the theory of phrase staying and the autocorrelation function, we design better performance nonlinear frequency modulation pulse compression radar.

基于逗留相位原理以及信号的自相关函数，设计了一种性能十分优越的非线性调频脉冲压缩雷达体制。

Based on the beat signal modelling, the frequency modulation soure nonlinearities affecting the radar range resolution are also discussed.

本文的主要创新之处在于：（1）总结了三毫米线性调频连续波雷达的关键技术，提出了实现这些技术的有效方法。

The impact of the thickness of volume H-PDLC grating on the wavelength selectivity of Bragg diffraction are simulated numerically, as well as the theoretic relationships among the refractive index modulation, spatial frequency and the H-PDLC diffraction efficiency.

计算机模拟了体光栅厚度对于布拉格衍射波长选择性的影响，以及折射率调制深度、空间频率和H-PDLC光栅衍射效率的关系。

In communications, the frequency range of the information bearing signals prior to combination with carrier wave by modulation.

在通信技术中，未经调制使之和载波结合之前，携带信息的信号所占有的频率范围。

Later, it makes some comparison with four kinds of modulation technique, and finally, it implements the three-level PWM switching power amplifier with the PWM technique. The power of the amplifier is 2kVA, and the frequency bandwidth is 10～3kHz. In the thesis, the author designs and makes the hardwares of the switching power amplifier. The hardwares contain power inverter rank circuit, control system circuit based on DSP, drive and isolation circuit, and protective circuit. The thesis also analyses the potential safety problems and put forward some solutions for the problems. Furthermore, the thesis accomplishes the software design of the control system, and successfully debugs it. The methods of designing higher power ampilfier are also discussed in the thesis. It analyses the feasibility of the methods, outlines the way of how to design higher power switching power amplifier, and does some experiments with the method of switches-parallelling.

根据电动振动试验系统对开关功放的要求，提出了以电感电流瞬时值控制技术为基础的三电平脉宽调制开关功放的设计方案，并通过系统仿真进行了原理性论证；然后设计并制作了开关功放的硬件，包括功率转换电路，基于DSP的控制电路，驱动、隔离电路以及保护电路；针对开关功放数学模型不易得出的特点，细致分析了模糊自适应PID控制方法，在此基础上编写了控制程序；研制出一台功率为2kVA，通频带为10～3kHz的三电平脉宽调制开关功放；论文中还探讨了实现大功率开关功放的方法，分析了各种方法的可行性，给出了实现大功率开关功放的思路，并进行了并联开关管实现大功率开关功放的实验。

I can not negligent, he should do what?

我不能不在意了，他要做什么呢？

It is very dangerous to swim in the river alone.

一个人到河里游泳是很危险的。