【作者】 刘文坚；

【导师】 褚庆昕；

【作者基本信息】 华南理工大学 ， 通信与信息系统， 2010， 博士

【摘要】 2002年FCC 02-48号报告公布了与超宽带(UWB)相关的多项技术标准,将3.1-10.6 GHz频段划归民用频段,使得UWB技术在无线通信方面的应用得到了进一步关注和更为深入的研究,也使UWB天线成为近年来天线领域研究的热点。UWB天线的设计和研究重点集中在体积小、带宽大、一定的辐射效率、全向覆盖特性、良好的脉冲波形保真度、较简单的制作工艺、成本低、易与有源器件和电路集成为单一模块等要求。此外,該报告将准毫米波段22-29 GHz的7 GHz规定为超宽带高清晰度车载雷达系统工作的频率范围。本论文在共面波导馈电圆单极子UWB天线的基础上,通过双C型槽的引入,调整和改变天线表面电流分布,分别从高频段和低频段改善的天线阻抗特性,扩展了天线的工作带宽,实现超级宽带特性和阻抗匹配,设计并制作了两个阻抗带宽频率比大于10 : 1的SWB天线。这两个天线不仅满足UWB带宽要求,其阻抗带宽还覆盖了包括FCC超宽带高清晰度车载雷达系统工作的频率范围在内的整个厘米波段,能满足日后更宽频的应用。本论文提出了一种对共面波导馈电平面天线进行切半,实现小型化的新结构,利用渐变微波带线馈电,解决由单纯半切引起的阻抗失配问题,使得上述小型化简单而有效。本文提出了两种宽度尺寸尺寸仅为11 mm的无线UWB天线,其宽度比USB设备的A型公口的宽度更窄的无线UWB天线,有助于UWB技术和WUSB标准相结合,在工程应用上有广阔的前景。为了解决大多数超宽带天线增益相对较小的情况,本文利用带拐角的并联渐变共面波导功分器和带C型槽的共面波导圆天线以及渐变MCS四边形天线,分别设计了二单元直线阵列和四单元直线阵列,提供了更高的增益和更灵活的方向性。对于短距离、高速、低耗的超宽带通信而言,除了频域特性,时域特性也是评价超宽带天线特性的重要标准。本文使用相关系数和脉冲宽度拉伸这两个重要的参数对超宽带天线及天线阵列进行了时域特性评估。更多还原

【Abstract】 Since the Federal Communications Commission (FCC) declaration of the frequency band 3.1 to 10.6 GHz for commercial application in 2002, inexpensive realization of ultra-wideband (UWB) systems have become one of the key topics in the industry worldwide. Challenges of the feasible UWB antenna design include the Ultra-wideband performances of the impedance matching, stable gain and omni-directional radiation character, Furthermore, as a key component of the UWB communication system for short-range high-speed and low power application, it is important to maintain the fidelity of pulse signal, more compact size, low manufacturing cost, and easily integrated with monolithic microwave integrated circuits (MMIC). Moreover, the report of FCC 02-48 provides for the operation of vehicular radar in the 22-29 GHz band using directional antennas on terrestrial transportation vehicles.In this thesis, two novel CPW-fed disc antennas etched with C-like slots are proposed with the impedance bandwidths ratio more than 10 : 1, the surface current distributes of the radiator was adjusted by C-like slots, thus, the impedance bandwidths characteristics were improved both in high end and low end frequency, the results shown that the advantages of super wide band (SWB), stable gain and omni-directional radiation patterns. The impedance bandwidths not only cover the bandwidth of 3.1 to 10.6 GHz, moreover, they cover the whole centimeter wave band which including the vehicular radar systems application.For more compact size, to half cut the CPW-fed UWB antenna was an effective method. 2 tapered micro-coplanar strip (MCS) fed UWB antenna were presented. The edge-fed tapered MCS structure including tapered strip and gradient slot is applied to reduce the dimensions and improve the impedance matching in the whole UWB band. The return loss is greater than 10 dB within UWB bandwidth. The results shown that return loss were greater than 10 dB within UWB bandwidth. On the other hand, the width dimension is only 11 mm, so that it can be easily integrated with the wireless USB equipments and suitable for various wideband applications.In order to improve the UWB antenna gain character, 2 units and 4 units UWB antenna array with gradient parallel CPW splitter were designed and study, which obtain the high gain and Flexible orientation.For short-range high-speed low power UWB communication, The time domain characteristics are significant criteria to estimate the performance of UWB antenna as well as traditional frequency domain parameters. The time domain characteristics were studied both the UWB antennas and array proposed in this thesis with correlation factor and the pulse width stretch ratio (SR).更多还原