【作者】 伍双杰；

【导师】 胡作启；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 随着通信器件的高频化、高速化发展,微波电介质材料在通信领域已经得到了广泛的应用,对高介电常数电介质材料微波性能的准确测量从而使其更好的应用于器件设计越来越受到关注。本论文对高介电常数电介质材料钛酸锶钡（BaxSr1-xTiO₃,BST）微波频率（X波段8¹2GHz,中心频率10GHz）介电性能与调谐性能的测试方法进行了设计、分析与改进,并应用改进设计后的方法对BST陶瓷与薄膜样品进行了测试,最终基于测试的参数对微波移相器件进行了设计与制作,并对其性能进行了测试。首先,选择微波谐振法与非谐振法组合测试的方法,主要包括谐振腔微扰法、矩形波导传输法与共面波导法。通过对传统的X波段谐振腔微扰测试法进行了改进,使其适合对高介电常数样品进行介电常数与损耗角的测量;应用矩形波导设计了移相器测试器件,并对其进行了4段1/4波长匹配以减小测试过程中的回波损耗,使测试结果更为准确,且该方法便于施加外压,适合对陶瓷样品进行实介电常数与调谐率进行测量;对共面波导法TRL测试器件进行设计及改进,使得该方法适合对薄膜样品介电性能与调谐率进行测试,并克服了薄膜厚度测量的误差对测试准确性的影响,对溅射电极的薄膜样品进行了光刻,制作出共面波导测试器件并进行了测试。应用上述测试方法组建成高介电常数陶瓷与薄膜样品的微波介电性能与调谐性能的测试方法系统。然后,应用微波网络分析仪组合射频探针平台及相关测试装置对设计制件出的BST基测试器件的微波性能进行测试,从器件的测试结果中推导出BST材料的性能参数,同时进行测试方法的误差分析,确定上述方案的测试误差。最后,基于BST的测试结果,应用ADS软件设计了共面波导加载叉指电容结构的BST薄膜微波移相器,并对其进行了器件制作与性能测试,得出器件移相度为25°/cm,最终总结出了器件对材料的要求及器件的设计改进方向。更多还原

【Abstract】 With the development of high-frequency and high-speed of the communications device, microwave dielectric materials have been widely used. At the same time, more and more attentions have been paid to the accurate measurement of the microwave performance of the high-k dielectric materials so that it can be applied for the design of the device.In this paper , the improved methods for microwave performance measurement of the dielectric permittivity and tuning properties of BaxSr1-xTiO3 (BST) were investigated and established at the microwave frequencies of X-band(especially at the main frequency of 10GHz). The microwave properties of BST ceramic and film were measured by the methods. The microwave phase shifting devices were designed and fabricated basing on the measurement results and their performances were also tested.First, the microwave resonance method combined with the non-resonance method is used for the measurement. They include cavity perturbation method, rectangular phase shifter method and coplanar waveguide method. The traditional cavity perturbation method was improved for the high permittivity and loss tangent measurement of the dielectric materials at X-band. The rectangular waveguide phase shifter was designed especially for the tuning properties measurement of the dielectric ceramic for the voltage can be easily put on. The 1/4 wavelength matching was designed to reduce the return loss during the testing process. The coplanar waveguide for TRL test method were improved for the use of BST film permittivity and tuning property measurement. The CPW devices were fabricated on the sputtered thin-film electrodes by lithography and they are tested at the same time. All the above methods constitute the test system for the dielectric and tuning properties measurement of the dielectric ceramic and film.Then, the combination of microwave network analyzer and the RF probe station were used for the measurement of the devices basing on the BST ceramic or film. And the material properties of BST were derived from the results of the devices performance. The analysis of the test errors caused by the test system, the devices and so on were taken into consideration to make the results more accuracy. The errors of the results were determined.Finally, the software of ADS was used for the simulation and design of BST coplanar waveguide phase shifter loading with inter-digital capacitor. The phase shift of 25 degrees per centimeter was got. And this finally determined the device requirement of the BST material and the how can the device can be improved.更多还原