查询词典 radio-frequency spectrum

The inention relates to a radio wave absorber which can achieve low cost, a small transportation volume, an excellent radio wave absorbing characteristic from a low frequency to a high frequency with a short length, a small or no difference in the characteristic of a polarization plane, and can be easily fabricated and worked.

本发明涉及一种电波吸收件、电波吸收体及其制造方法、以及电波暗室，用于实现下述的电波吸收体，其成本低、输送体积小、长度短、从低频到高频能获得良好的电波吸收特性，没有极化面特性差或该极化面特性差较小、重量轻、结构强度高、制造和施工容易。

It is made up of a guide needle (11) which houses two or more active radio-frequency wires (14, 15) connected at their proximal end to a radio-frequency generator and each one having a spiraled, helicoidal or spiral, distal segment 14'.

其由引导针(11)构成，该引导针藏有两根或更多活动射频导线(14、15)，该导线在其近端连接到射频发生器，并且每根导线具有绕成螺旋的、漩涡状的或螺旋状的远端段(14′、15′)。

In wireless broadband digital communication, Inter-Symbol Interference caused by time disperse of radio channel is one of main factors that limit bandwidth of communicated information and system performance of communication. In receiver, Orthogonal Frequency Division Multiplexing system can easily cancel ISI and equalize frequency-selective fadings that are both caused by time disperse of radio channel.

在这一系统中，无线信道时延扩展引起的符号间干扰是限制传输性能和信息速率的主要因素之一；而在消除符号间干扰和均衡由无线信道时延扩展引起的频率选择性衰落方面，正交频分复用(Orthogonal Frequency Division Multiplexing，OFDM)技术具有明显优势。

Japan and Korea of the respondents unequivocal inventory management will be a radio frequency identification technology's biggest gainers in two countries accounted for 88% and 92% of the respondents will inventory management as the implementation of radio frequency identification technology.

日本及韩国的被访者明确认为库存管理将是无线射频识别技术的最大获益者，两国中分别有88%和92%的被调查者将库存管理作为实施无线射频识别技术的首选。

Communication ; data ; radio frequency system/radio frequency identification ; reader ; electronic tag ; binary search algorithm

通信； 数据；射频系统/射频识别；读写器；电子标签；二进制搜索算法

Aiming at the project request, the paper firstly introduces the theory of Frequency Hopping Communication, the theory of sampling and the principle of spectrum analysis using discrete Fourier transform, then combined with the characteristic and superiority of FPGA designs a channelizing detection method for the carrier frequency in Ultrashort Frequency Hopping signal based on FPGA.

然后结合现代可编程器件FPGA的特点与优势，设计了一种基于FPGA技术的信道化电子侦察方案。

The results of the study are as follows: 1 Wigner′s time-frequency analysis of the geoacoustic signal is of a clear physical meaning, which can be described as the energy distribution in time and frequency domain, and can reveal the frequency spectrum essential features of non-stationary geoacoustic signal.

研究表明：1。地声信号的Wigner时-频分析具有明确的物理意义，它可表述为信号在时间和频率域上的能量分布，揭示了非稳态地声信号频谱的本质特征。

On the basis of analysis and comparison of conventional and some modern dielectric loss measurement methods in this paper, considering the difficulty consist in the dielectric loss measurement, such as the problem of the locale measurement of dielectric loss the suffering the interference of the electric field in the electrified wire net, the influence of harmonics and the leakiness of frequency spectrum due to the change of the frequency in power supply etc. a new measurement method which the frequency conversion anti-jamming technology combines the fundamental waves phase detachment method is presented.

论文在分析了传统介质损耗测量方法和现代介质损耗测量方法的基础上，针对介质损耗检测中存在的技术问题，如现场测量时工频电网强电场干扰问题、高次谐波影响问题、供电电源频率改变所引起的频谱泄漏和栅栏效应等问题，提出了采用变频抗干扰技术和基波相位分离法相结合的新型测量方法。

The working load of engin e in plowing can be taken for stable and normal random load whose power spectrum peak value is below 2 Hz. The working load of engine in rototilling contains bo th periodic element whose fundamental frequency is rotating speed of the blade s haft and normal random load of which the parts of energy centers in fundamental frequency and others are distributed over wider frequency band.

证实了犁耕作业发动机的载荷可以认为是平稳的正态分布的随机载荷，其功率谱曲线的谱峰在低于2 Hz处；旋耕作业发动机的载荷是兼有随机成分和周期成分的动态载荷，其中周期谐波的基频为刀轴转速，随机成分一部分能量集中于基频以内，部分分布于较宽频率范围。

A silent communications system in which nonaural carriers, in the very low or very high audio-frequency range or in the adjacent ultrasonic frequency spectrum are amplitude- or frequency-modulated with the desired intelligence and propagated acoustically or vibrationally, for inducement into the brain, typically through the use of loudspeakers, earphones, or piezoelectric transducers.

一个沉默的联系是不承载听觉，在非常低或非常高音频范围里，或在邻近的超音速的频谱中，这是广阔的-或带有期望的智能并且传播声学的频率调节或振动，为了刺激大脑内部，典型的是通过利用扬声器，耳机，或压电式换能器。

The use of the web to spread fears that flicking the switch on the LHC could create a Black Hole that could swallow up the Earth particularly concerned him, he said.

他说，使用互联网散布恐慌说启动LHC会生成一个可能吞噬地球的黑洞的做法让他感到忧虑。

Not a single word have I written down.

我一个字也没有写下来。