宽频带

Planar Archimedean antenna has some advantages as wideband,small volume and good performance in circularly polarizing ,so it has broad appliance prosperity.

平面螺旋宽带天线具有频带较宽、体积较小、圆极化性能较好等特点，应用范围很广。

The dual-band differential LNA use Inductive source degeneration structure, a matching network is used for the LNA to develop dual-band. The micro-mixer use a matching network shunt and parallel LC elements to develop wide-band matching. The biasing method reduces the"voltage headroom" difficulties inherent to the Gilbert cell, and the mixer linearity can be improved using this biasing method "Charge -Injection"by accurate adjustment of the input MOSFET operating point. The complementary VCO based on 2.5GHz, and tuning output buffer to approach 2GHz/5GHz dual-band for dual-band down-converter with MMIC technology.

其中双频差动低杂讯放大器，本电路用Inductive Source Degeneration 架构，在匹配网上设计，使低杂讯放大器工作在个频带上达成双频带的效果；CMOS 微混频器上采用LC串联、并联电路做匹配，达到宽频匹配的效果，并加入了"Charge-Injection"的方法来改善"voltage headroom"的问题，并同时提高线性度的表现；互补式压控振荡器以2.5GHz为基频的振荡器为出发点，透过电路的调整，以期达成2.5/5GHz的双频带需求，能够完整达成双频带接收机系统。

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。

The new antenna has the advantages of sim ple structure, easy feeding and a wide frequency range, and circular polarized wave. The characteristics are m uch better than a bifilarbackfire helicalantenna, a shortbackfire antenna and a backfire...

它具有结构简单、馈电方便、遮挡小、频带宽、增益高且易于产生圆极化波等优点，性能远优于带相同接地板的螺旋天线、普通短背射天线以及单线背射螺旋作馈源的短背射天线。

These antennas can cover GSM900/DCS/PCS/UMTS operation. In the chapter 2, the antenna is designed based on the concept of monopole antenna. Furthermore, the antenna structure have two radiant paths and coupled each other at tail end to do impedance matching. In addition, to raise distance between radiation plane and ground will avoid capacitative effect effectually. In the chapter 3, the antenna is designed based on the concept of planar inverted-F antenna. Furthermore, that the antenna structure have two radiant paths and coupled each other at tail end to do impedance matching is similar to chapter 2. But there is a difference in them. We can choose the short position to change input impedance at this structure. In the chapter 4, the antenna is designed based on the concept of planar inverted-F antenna which takes coupled-fed. It will produce the first mode and high-order mode near the frequency, 900MHz. The feature of this type is to reduce the volume effectually. This antenna can not only cover GSM900/DCS/PCS/UMTS operation but maintain good radiation efficiency. Finally, we will compare three antennas, and develop procedure with industrial view, and propose the prospect of the GSM/GPRS antenna in PND, as a conclusion.

在第二章中，我们使用单极天线设计概念，使用双路径架构并於末端耦合来对天线阻抗做匹配，产生涵盖GSM900/DCS/PCS/UMTS四频操作频带，并提高与接地面的辐射高度，以避免电容效应，使天线具有良好的辐射特性；在第三章中，使用倒F形天线设计概念，使用双路径架构於末端耦合，并於辐射臂上采取适当接地点电感效应作输入阻抗匹配，达成涵盖GSM900/DCS/PCS/UMTS系统的四个操作频带；在第四章中，采用倒F形架构并使用耦合馈入方式，使得长辐射金属臂在低频900 MHz附近产生共振，产生低频基频模态及高阶模态，以达成宽频及频宽涵盖GSM900/DCS/PCS/UMTS频带操作，并有效缩减使用体积；最后，分别比较此三种架构的优缺点，再加以业界角度来思考，研发产品天线的流程及思考方向，以及天线应用於可携式导航装置中未来的展望作为本论文的总结。

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。

We also discuss observations of infragravity waves on broadband ocean bottom seismometers located off-shore California, and their relationship to wind waves and seismic noise, showing that the ocean/solid earth coupling occurs near the coast.

我们也讨论了在加州近海布设的宽频带海底地震仪观测到的重力波以及它们与风波和地震噪音的关系，发现海洋/陆地的耦合发生在近海。

There is a spectral band with the same center-frequency as that of the incidence pulse and two wider sidebands.

对聚合后光脉冲的频谱进行了分析，除了观察到与入射脉冲相同的中心频带外，还存在两个频带较宽的边带。

A broadband circular polarization antenna is then presented. Besides, we discuss how the different size of ground plane affect the antenna's performance.

其次，本文设计了一个宽频带的圆极化天线，并在此基础上讨论了不同大小的地板对圆极化天线性能的影响。

Pn wave velocity structure and anisotropy in the central Tien Shan are investigated by using seismic arrival data from the temporary broadband network and the Kyrgyzstan seismic network.

利用宽频带流动地震台阵GHENGIS和吉尔吉斯地震台网KNET记录的地震波走时数据，反演了中天山地区的Pn波速度结构和各向异性。

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。