| The ultra-wideband technology (UWB Technology) is a new rapidly rises wirelesscommunication technology recently, with the top-speed development in science andtechnology, the appearance of UWB antenna solved a lot of problems in traditionalwireless communication technology field which bothered for so long, that is why UWBantenna is no doubt the focus of UWB technology. As the core component, theperformance of UWB antenna plays a vital role in the whole ultra wideband (UWB)system. Merits of UWB antenna are as follow, compact structure, low sensitivity ofchannel fading, low power consumption, low probability of interception, the accuracyof positioning and ease of fabrication etc. Combined with radio frequency technology, itcan replace the traditional wire communication. Ultra wideband (UWB) system alreadycovers several other wireless standards already，such as Wi-Fi and WiMAX whichcenter frequency is around2.4GHz and3.5GHz and WLAN in the frequency band of5.15~5.35GHz and5.725~5.825GHz. How to reject the interference and realize thecompatibility between these systems, are the problems which scientific researchpersonnel dedicated to. This thesis start from the UWB antenna theory, introduces thesystem requirements for ultra-wideband antenna, band broadening method andband-notched characteristics realization method.This thesis started from a survey on the UWB antenna and its analysis methods，then discussed the major parameters, structures and feed methods, at last designed twokinds of UWB antennas with different feeding modes and structures，using coplanarwaveguide and micro strip feedback, by adjusting the size of pitches to realize theoptimization of the antenna performance. The proposed antennas provide an ultra widebandwidth of2.0GHz~10.6GHz with four and three band-notched characteristics,whose VSWR is less than2，reached the design requirements.At the very last，summarized the whole thesis，and put forward the prospects forfuture work. |
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