The Design And Research Of Miniaturization Planar UWB Antenna

Ultra wideband communication technology can merely be utilized in the areas ofmilitary security such as radar positioning, electronic countermeasures, while the cilivianuses are not allowed before2002. Nevertheless, the UWB communication still has greatpotential and attracts widespread attentions since its high efficiency, low capacity, low errorrate and so on. Either the traditional communications industry or the novel ultra widebandcommunication system which ueses electromagnetic waves to transmit information,depends on the antenna to move on usally. Even in the systems of radiation energy,antennaalso plays an improtant role. Moreover, the development of ultra widebandcommunications further promote the emergence and application of ultra-wideband in theantenna field. The research and design of antennas which are applied in the field of ultrawideband communication, are focused on miniaturization, large-bandwidth, multiple trap,low cost and directionality. The frequency of ultra-wideband contains plenty of narrowcommunication bands such as WLAN band (5.15GHz-5.825GHz) and X band (7.2GHz-8.6GHz). Aming at restrain the interference signals beween the ultra widebandcommunication system and the narrowband system, the ultra wideband antenna ought topossess the properity of trapping waves. Therefore,the ultra-wideband antenna which cantrap waves become popular in recent years and are also the emphasis of this paper. On theother hand, With the further pursues for the quality of images and videos and theinsufficiency of limited spectrum resources, multiple input multiple output (MIMO)antenna can effectively slove these problems,which is another focus of the paper.Firstly, we simply introduced the definition and development history of ultra-wideband,and summarized the research status and relevant theoretical knowledge of the band-notchedultra-wideband microstrip antenna. Secondly, we designed a novel ultra-wideband antennaon the basis of basic rectangular microstrip. Through the method of current cutting, therectangular microstrip antenna bandwidth characteristics was improved. And a newpentagon ultra-wideband microstrip antenna was prepared at the frequency of3.1GHz-10.6GHz. On this basis, we successfully designed a single band-notched UWB microstrip antenna to effectively shield the WLAN band(5.2GHz-5.8GHz) by adding the C type slot.After obtaining the analysis and simulation results, we processed and then tested of thespecific antenna. Thirdly, on the foundation of the single band-notched antenna, werealized the effective separation of X-band (7.2GHz-8.6GHz) and retained the notch forthe WLAN band by adding a pair of broken line gaps extended to the patch on the antennafeeder. Then, a double band-notched antenna was fabricated and measured, and themeasured results are in good agreement with the simulated results. Finally, based on otherprevious works, we put forward a novel ultra-wideband microstrip antenna with thefanshaped slot structure of multiple input multiple output. As a result, the size of antennawas smaller, and antenna isolation degree increased to more than22dB. The test results ofthe fabricated antenna were consistent with the simulation’s, which proved the validity ofour proposed design methodology.