【作者】 王磊；

【导师】 于军；

【作者基本信息】 华中科技大学 ， 集成电路工程， 2011， 硕士

【摘要】 铁电薄膜介质移相器相比较其它类型的移相器具有成本低、体积小、抗辐射、驱动功率低、可靠性强等优点而备受人们青睐,是军用雷达领域的热点研究对象。本文主要对叉指电容加载共面波导移相器结构做了简要的理论研究和实验制备,给出了共面波导与外接电路匹配的结构(CPW-MS)结构设计,重点讨论了双周期结构对器件性能的改进作用,最后通过半导体工艺成功地制备出了双周期、单周期移相器单元结构,并给出了器件的测试方案。利用HFSS软件对叉指电容的结构参数进行了模拟仿真,研究了叉指电极宽度、叉指电极间隙、叉指电极长度对器件性能的影响,结果发现大的移相量和小的损耗很难同时满足,需要根据具体情况对参数进行折中选择。对具有CPW-MS转换结构的移相器模型也做了HFSS仿真,结果发现在微带线(MS)宽度为一定值时,转换结构的角度越大,即转换结构的长度越小,器件的损耗越小,然而器件的移相量只在长度较大时有明显的变化。对双周期结构相邻叉指电容之间的不同距离进行了研究,最终得出可以在更宽的频段内阻抗匹配的一组L1和L2的值,并且这种相邻叉指电容位置的变化还可以降低某单个频率点的损耗,优化了移相器的性能。结合实际制备工艺以及本论文和本实验小组的相关结论给出了移相器的最终设计参数:信号线宽度为40μm~60μm,缝隙宽度在没有叉指电极存在时为10μm~20μm,有叉指电容时我们取为70μm,叉指长度40μm~60μm,叉指宽度4μm~8μm,叉指间距8μm~12μm;衬底主要有Sapphire、Si,电极材料主要有Al、Cu、Pt;BST薄膜厚度为0.3μm~0.8μm,Al电极厚度在1.152μm以上,Cu电极厚度0.934μm以上。利用剥离工艺成功的制备了单周期和双周期两种移相器单元结构,图形完整清晰,制备效果良好。最后提出可用在片测试技术对器件性能进行测试分析。更多还原

【Abstract】 Compared with others, the ferroelectric films based phase shifter has many better advantages, such as low cost, small valume, anti-radiation, small drive power, high reliability and so on, and it has attracted much more attention especially in military radar field in recent years. In this dissertation, we have done some theoretical research and experimental fabrication of interdigital capacitor loading on the CPW, designed CPW-MS transition structure which makes CPW matching with external microstrip circuit, and discussed the improvement of double periodic structure. At last, the unit structure of single periodic and double periodic phase shifter is fabricated successfully using semiconductor technology, introduced testing solution of the phase shifter.The effection to device performence of interdigital capacitor structure parameters including the width and length of interdigital electrode, the width between interdigital electrode is analyzed using HFSS software. According to result analyzed, it is difficult to obtain large phase shift and small loss simultaneously, and the parameters chosen need to compromise according to actual situation.The phase shifter model with CPW-MS transformation structure is simulated by using HFSS software and when the width of microstrip is a fixed value, the larger the angle of CPW-MS, namely the smaller the length of CPW-MS, the smaller the loss, but the phase shift of device can not change significantly unless the length of CPW-MS is large enough. The different distances of adjacent interdigital capacitor of double periodic structure are discussed, and got the optimal length of the L1 and L2 that lead to impedance matching in wider band; moreover as a result, the loss of some single frequency point can be reduced, optimize the performance of device.The final design parameters is derived by relevant conclusions of this paper and experimental group as width of signal line is 40μm to 60μm, the width of slot is 10μm to 20μm without interdigital electrodes, otherwise is 70μm, the length of interdigital electrode is 40μm to 60μm, the width of interdigital electrode is 4μm to 8μm, the width between interdigital electrode is 8μm to 12μm; the substrate can be Sapphire or Si; electrode materials can be Al、Cu and Pt; The thickness of BST thin films is 0.3μm to 0.8μm, the thickness of Al and Cu is over 1.152μm and 0.934μm respectively.The unit structures of single and double periodic phase shifter are fabricated successfully using lift-off technology, the graphics are complete and clear and the fabrication effect is good. At last, on-chip test technology which can be used for analysis of device performence is proposed.更多还原