【作者】 汤小蓉；

【导师】 钟顺时；

【作者基本信息】 上海大学 ， 电磁场与微波技术， 2009， 博士

【摘要】 根据我国《国家中长期科学和技术发展规划纲要(2006-2020)》,地球观测技术已被列为“十一五”期间十项需超前部署的重点前沿技术之一。作为一种重要的微波遥感技术,合成孔径雷达(SAR)技术凭借其全天候、全天时的工作特点和高分辨率的成像质量,已在军事和民用领域取得了广泛的应用。本论文主要对应用于双波段双极化天线阵的介质谐振器天线(Dielectric resonator antenna简称DRA)作了一些较为深入的研究工作,在此基础上提出共用口径双波段双极化阵列的新方案。同时,本文还对RFID读卡器天线(Radio Frequency Identification,简称RFID)做了一些研究。本文的主要内容包括以下几方面:第一,综述了近年来双极化DRA的各种实现方法,讨论各种方法的优点和不足,并作了比较与总结。阐述了近十多年来用于SAR的共用口径DBDP阵列的发展,着重于结合具体的技术指标考察各种设计方案,总结出设计思路和设计中需要考虑的问题。此外,又综述了RFID读卡器天线技术。第二,文章详细介绍了双极化DRA的设计,探讨了DRA形状、大小等参数对天线性能的影响,考察了平衡馈电激励方式在改善天线交叉极化指标方面的作用,并分别对平衡探针和平衡缝隙馈电进行了参数研究。加工了实验天线,其实测的水平和垂直极化阻抗带宽(S11≤-10dB)分别达7.9%和11.8%,而实测隔离度在5.46~5.9GHz带宽上大于35.9dB,居当前国际先进水平。第三,提出共用口径S/X双波段双极化DRA阵列的新方案:将S波段振子和X波段DRA交错排列,在共口径结构下实现1:3的频率比,X波段DRA通过平衡缝隙馈电技术来提高端口隔离度和降低交叉极化电平,S和X波段仿真的交叉极化电平分别为-32.9d和-47.5dB,天线的水平极化具有一维的±24°相位扫描性能。第四,研制了用于RFID读卡器的低旁瓣、圆极化微带天线阵。一副实验天线的实测与仿真结果吻合得很好,水平面2.56GHz的实测旁瓣电平低至-21dB,实测极化轴比为1.1dB。更多还原

【Abstract】 The earth observation technology has been listed as one of the top ten leading techniques that were planned in advance in the 11th Five-year Plan by the“National Scientific and Technical Plan Outline in the Long and Medium Term (2006-2020)”of China. As an important remote sensing technique, the SAR (Synthetic Aperture Radar) system is featured by all-time and all-weather capability and high-quality image, which has found wide applications in both military and civilian systems. This dissertation is dedicated to the detailed study on the dielectric resonator antenna for dual-band dual-polarized (DBDP) array applications. Under this background, a novel design for DBDP arrays is proposed. On the other hand, low-sidelobe circularly-polarized microstrip arrays for RFID applications are studied. The main contents are outlined as follows:Firstly, this dissertation makes an overview on various techniques of dual-polarized dielectric resonator antenna (DRA) in the recent years, discusses the advantages and disadvantages of these techniques, then presents a comparision and the conclusion. It also makes an overview on shared-aperture DBDP arrays for SAR applications in the recent decade. The overview highlights the evaluation of different designs associated with their technical specifications and leads to conclusions on the design approaches and considerations. In addition, this dissertation introduces an overview on antenna techniques for RFID Readers.Secondly, the dissertation provides a detailed coverage on the design of dual-polarized DRA, the influence of shape, size and other parameters of DRA on the antenna performance, and the improvement of cross-polarization performance through a balanced excitation method. Parametric studies of balance-probe-feeding and balanced-slot-feeding are presented. The experimental antenna was fabricated. The measured impedance of 7.9% and 11.8% (S11≤-10dB) are achieved at horizontal and vertical polarization, respectively. The isolation is larger than 35.9dB from 5.46GHz to 5.9GHz, which reaches the international advanced level.Thirdly, a novel design for shared-aperture S/X DBDP DRA arrays is proposed which combines S-band microstrip dipoles and X-band DRAs in an interleaved manner to achieve the frequency ratio of 1:3 in a shared-aperture configuration. In the design of X-band DRA, the balanced-slot-feeding technique is applied to improve the port isolation and reduce the cross-polarization level. The simulated cross polarization levels are -32dB and -47.5dB at S and X band, And the±24°phase scanning performance is achieved for one dimension with the horizontal polarization.Finally, the low-sidelobe circularly-polarized microstrip array for RFID application is developed. The simulated results of a experimental antenna are in good agreement with the measured ones. The measured sidelobe level of -21 dB in the horizontal plane was measured at the frequency of 2.56 GHz with the measured axial ratio of 1.1 dB.更多还原