查询词典 radio-frequency spectrum

The bias of cyclic periodogram with ssinc window is analyzed in both spectrum frequency direction and cycle frequency direction, and that the TA cyclic spectrum estimation is unbiased is analyzed. The average method of cyclic periodogram is also derived in terms of STFT.

论文中通过分析加ssinc窗的循环周期图在谱频率方向和循环频率方向的偏差，表明TA循环谱估计是无偏估计，并根据STFT方法，推导了使方差得以减小的平均循环周期图方法。

By projecting signals with different frequencies into the subspace I, the signal with the supply frequency has the maximum value. Consequently, in the spectrum of the reciprocal of the projecting value, the supply frequency component is cut off and the fault feature component emerges in the spectrum.

把不同频率的信号投影到子空间I，基频信号在该空间的投影将远大于其他的频率分量，因此在投影的倒数谱中，基频分量被抑制，凸显出了故障频率分量。

The frequency spectrum of noise is very wide, and will superpose with useful signal that has the notable influence to digital measurement and frequency spectrum analysis. Base on it, the method of solving zero floating problem of Waveform digital reconstruction process is proposed.

噪声的频谱噪声频谱很宽，将与有用信号的频谱重叠，对数字测量、信号处理和谱分析有显著的影响，并提出了解决波形数字重构中数字示波器零漂影响的方法。

modulation is the transmission of information to be loaded onto a high-frequency signal in the process.amplitude modulation using signal to control the rate of carrier,with its linear modulation signal changes,and maintain the same carrier frequency.in the amplitude modulation,in accordance with the strength of signals in the spectrum of different components,it is divided into ordinary am (amplitude modulation standard am),with inhibition of bilateral carrier am,the carrier single sideband suppression am.the main difference is the different methods and structure of the spectrum.

摘 要：调制是将要传送的信息装载到某一高频信号上去的过程。振幅调制是用调制信号去控制载波的幅度，使其随调制信号线性变化，而保持载波的频率不变。在幅度调制中，根据已调信号的频谱分量不同，分为普通调幅、抑制载波的双边带调幅、抑制载波的单边带调幅。它们的主要区别是产生的方法和频谱结构不同。

Then based on CWMS, we propose a new method to enhance the resolution of seismic traces. Firstly, we divide the seismic signal into proper segments by Gabor molecule-windows adaptive to the signal, where each segment is regarded stationary, and then transform it into the Gabor domain. Secondly, we deal with the amplitude spectrum for each segment to expand the frequency band of the spectrum in the Gabor domain. Finally, taking inverse Gabor transform on modified time-frequency coefficients, we get the high-resolution signal.

然后基于变子波模型，提出了一种新的提高地震记录分辨率的方法：第一步，用自适应于地震记录的Gabor分子窗把地震记录恰当地划分成若干片断，每段内信号近似平稳，然后将地震记录变换到时间-频率域；第二步，在变换域对每个分子窗内信号的振幅谱进行处理以拓宽频带；最后把处理后的时间-频率域函数反变换回时间域得到提高分辨率后的结果。

By simulating the absorption spectrum of molecule iodine absorption filter ranges from 470nm~550nm, this paper selects the absorption spectrum of molecule iodine absorption filter that satisfies the requirement of frequency discriminator in detecting system and ascertains the center emission frequency of laser emitter.

以基于边缘探测技术的激光雷达监测大气信道和海洋水下信道环境参数为例，通过仿真出碘分子吸收滤波器在470nm～550nm区间范围内的吸收光谱谱线，选择出合适的吸收谱线并确定发射激光信号的中心频率，并在此基础上，给出了满足探测要求的激光发射信号单稳频指标，为实际探测系统的设计奠定基础。

In the last new years , as the demands of wireless communication system grows rapidly , the bands of microwave frequency had been saturated with various communication applications . To achieve wider spectrum for high-speed and high-capacity transmission , bands of millimeter-wave frequency are the solution of this problem . The advantage of MMW wireless communication systems is wider bandwidth comparing with microwave communication systems . To utilize the spectrum efficiently , many methods of complexly digital modulation is proposed . The more complex modulation , the higher linearity is required , and more various phase of signals are required to accomplish process of modulation . Therefore high-linearity and quadrature-phase modulator and demodulator are the emphasis of this thesis . For high level of integration , high performance and low cost , this chip is fabricated by the complementary oxide semi-conductor 0.13um process . A compact size of direct down-conversion and direct up conversion circuits will be presented in this thesis .

近年来随著无线通讯产业的蓬勃发展，微波频带已经趋近於饱和，为了追求更宽的频谱来达到更快传输速率及高资料容量的传输，宽频的毫米波频段提供了解决此问题的途径，毫米波无线通讯系统提供了相对於微波通讯系统宽频的优点，且为了更有效的使用频谱，各种不同且复杂的数位调变方式及方法被发表出来，越复杂的调变方式其所需的线性度越高，且需要更多不同的相位讯号来完成调变的过程，因此高线性度及四相位的调变及解调器将是此篇论文的研究重点，为了达到高整合性，高效能，及低成本的电路设计，我门利用互补式金氧半导体制程来完成此电路设计，因此一小面积的直接降频(Direct down-conversion)及直接升频(direct up-conversion)电路将在文中介绍。

EPL only monopole radio frequency produces controllable depth monopole radio frequency by the electromagnetic field vicinity in skin fibre may tighten up the dermis and the hypoderm room tier, the maximum temperature is located in skin underneath under making monopole irradiate several millimeters, the cuticle is not good in by the comfort scalding , curing safety.

EPL独有的单极射频通过电磁场在皮肤的周围产生深度可控的单极射频场，可收紧真皮和皮下组织间的纤维层，使单极照射下最高温度位于皮肤下面几毫米，表皮不会被烫伤，治疗安全舒适。

6800G Blu-ray version of the wireless kit is a colorful Technology recently recommended a new suite of wireless power, using zero-latency 2.4GHZ radio frequency technology, can receive information from up to 10 meters; 16 radio channels, can be automatically frequency-hopping; keyboard with full - The new ultra-thin keycap, laser character, mute better effect, and the permanent lossless.

多彩科技是国内著名的外设厂商，商品性价比非常高。6800G蓝光版无线套件是多彩科技近期全新推荐的一款无线省电套件，采用零延迟2.4GHZ无线射频科技，接收距离可达10米；16个无线频道，可自动跳频；键盘采用全新超薄键帽，镭射字符，静音效果更佳，且永久不掉字。

After analyzed RFID and NFC technology, they are considered as radio frequency communication and listed up some examples of other radio frequency.

本文在分析射频识别和近场通信的基础上，指出它们同属射频通信，而且列举了射频通信的其他技术。

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。