【作者】 马晓亮；

【导师】 罗先刚；

【作者基本信息】 中国科学院研究生院（光电技术研究所） ， 测试计量技术及仪器， 2014， 博士

【摘要】 在现代雷达、无线通信系统中，单纯线极化天线已很难满足需求。高增益、圆极化天线由于具有抗雨雾干扰、抗多径效应等特性受到了广泛的关注。传统圆极化天线由微带、螺旋等结构构成，存在带宽窄、极化方式单一等缺点，而阵列结构虽能提高天线增益，但存在馈电损耗、设计复杂等技术缺陷。近年来出现了一种人工结构材料，它对电磁极化具有优良的调制特性，有望为高性能圆极化天线设计提供全新的技术途径。本文将围绕人工结构材料对电磁波极化的调制机理展开研究，设计出了各向异性结构极化调制材料和手性结构极化调制材料，在此基础上开展了动态极化调制材料的设计，并探讨了相关材料在圆极化天线中的应用研究，主要研究工作包括以下三点：1、针对传统极化调制材料较厚（1/4波片），集成度低等问题，提出利用各向异性结构对电磁波相位的调制机理，设计出厚度仅为λ/20，相对带宽为17%的线极化转换为圆极化的调制材料；针对现有手性人工结构材料工作频段少、损耗大等问题，提出利用平面螺旋结构实现圆极化分离的新原理和方法，材料插损小于0.6dB，此外利用该结构还进一步拓展了手性人工结构材料的工作频段，实现了多频的圆极化分离。2、针对未来无线通信系统对多极化天线的迫切需求，提出在材料单元结构中集成电控元件的设计方法，并分别利用收发贴片结构和手性结构设计出动态调控型极化调制结构材料，实现了线极化、圆极化波的相互切换，极大拓展了人工结构材料的极化操控性能。3、为了满足高增益圆极化天线的应用需求，提出将各向异性结构极化调制材料与传统线极化贴片天线相集成的设计方法，实现了圆极化电磁波的出射，天线增益提高了4dB；此外还提出将低损耗的手性极化结构材料加载于传统喇叭天线口径面，构造出了Ku波段双圆极化的新型天线，能初步满足卫星通信上行链路和下行链路对圆极化天线的技术要求。更多还原

【Abstract】 As the improvement of modern communication technology, the requirement ofcircularly polarized antenna with high gain and multi-polarization character has beenmore and more urgent in satellite communication and inside communication domain.However, traditional circularly polarized antennas, like microstrip antennas, helixantennas et al. can not satisfy this requirement for their low gain and single polarizationstate characters. Metamaterial，which expands rapidly in recent years can greatlymanipulate the polarization states of the incident electromagnetic waves, provides a newapproach to design circularly polarized antennas with high performance. In thisdissertation, we focus on the polarization conversion of metamaterial and designbiaisotropic and chiral metamaterials. Circularly polarized antennas with high gain andmulti-polarization are constructed by integrating the designed metamaterials withtraditional microstrip antenna and horn antennas. The main work of the dissertationincludes:1. The traditional polarizers (λ/4wave plate) are mostly very thick and hard tointegrate. In order to solve this problem, we designed a metamaterial realizes thepolarization conversion in17%relative bandwidth, and has the thickness of less thanone twentieth based on the anistropic structure. In order to improve the performance ofchiral metamaterials, which has the problem of few working frequency bands and highloss, we provide new theory and method to achieve circular splitting based on planarspiral chiral structure. The designed chiral metamaterials with the minimum loss of only0.6dB, and can convert the incident linearly polarized wave into different circularlypolarized waves at different resonances，which increases the working bands of the chiralmetamaterial.2. To satisfy the requirement of multi-polarization in modern communicationsystems, we propose a new method to construct polarization reconfigurablemetamaterial by loading diodes in the unit cells. And two new kinds of metamaterial aredesigned with the transmittarray and chiral structure, which switch the polarizationstates of the outgoing wave between linear polarization and circular polarization.Therefore, this tunable metamaterial greatly broaden the polarization manipulationcharacter of the metamaterial. 3. In order to increase the gain of the antennas, the anisotropic metamaterial isintegrated with a microstrip antenna to convert its radiated field into circularly polarizedfield, and greatly increase its gain level by4dBi. Besides, a dual-band dual-polarizationKu band circularly polarized antenna was constructed by integrating the chiralmetamaterial with a traditional horn antenna, which satisfies the requirement of theoperating bands and polarization states of satellite antennas in up-link and down-link.更多还原