频带

Along with the development of the modern and high technique war, put forward the new needs to the big power microwave vacuum tube, and provided the good environment for its development.

随着现代高技术战争的发展，对大功率微波电子管提出了新的需求，并为其发展提供了良好的环境，促使真空电子器件向更大功率、更宽频带、高效率和高可靠性方向快速发展。

Primary analysis and discussion on some typical earthquake precursor anomalies which appear in the range of 500 km are done according to the data recorded by the RZb-1 type digital strain gauge with high precision and broad channel.

就库尔勒台用高精度RZB-1型宽频带数字应变仪先后在500 km范围内记录到的几次较典型的MS5.5左右地震的前兆异常作了初步分析与探讨。

With the recent appearance of broadband OBS, the background noise in the extended frequency range is even more significant.

现在广泛使用的宽频带洋底地震计在扩展频段内记录到的背景噪声更强。

Sound installations and working bands need powerful wireless tools that can be set up quickly and used confidently.

合理有效的配置和工作频带需要功能强大的无线设备才能实现，用户可以快速地安装这些设备并安心地使用。

It possesses the advantages such as small volume , wide transmission belt of frequency , no saturation problem and without harmonic vibration point etc.

采用电阻分压器来替代电磁式电压互感器，可将初级电压直接转化为10 V 以内的微信号，具有体积小、传输频带宽、不存在饱和问题、无谐振点等优点。

Being characteristics of the broad transmission bands an...

由于传输线变压器具有通频带宽、易于制作的特点，在功率超声领域将有可能得到广泛的应用。

This paper presented the main functions and characteristics of Multisim8.0, and the main qualities of high frequency tunable amplifier such as voltage gain, transmission bands and selectivity were studied using simulation analysis and testing technologies of Multisim 8.0. The results are visual and precise, and prove the theory very well. This software has powerful simulation and analysis function, by which the analysis and design of high frequency circuit are not only more precise and credible, but also more closed to the real circuit running status.

本文介绍了Multisim8.0仿真软件的主要功能及特点，并结合该软件对高频单调谐放大电路的电压增益、通频带、选择性等主要质量指标进行了测试与仿真分析，结果直观、精确，很好地验证了理论，表明该软件有强大的仿真和分析功能，在实现高频电路分析和设计方面不仅高效、可靠，而且具有逼近真实电路的效果。

Transmission bands; ultimate gain; output-power; output voltage RMS

通频带；最大增益；功率输出；输出电压有效值

The paper extended researches the microstrip six-port net project deeply, ADS tools are adopted to model and simulate this project, and then the paper analyses the characteristic of radio channel both transmitter and receiver, analyses the extended transmission bands and simulates the adaptability, then designs lumped-distributed microstrip filter.

文中对微带六端口射频通道方案进行深入的扩展分析，采用ADS建模及仿真研究，分析了发射通道和接收通道的特性，通过对通频带扩展及适应性仿真的分析，设计了集总—分布式微带滤波器，最后也与零中频混频方案比较了各自的差异性。

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。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。