基于LTCC的微波电容设计与研究

发布时间：2018-05-26 06:06

  本文选题：LTCC工艺 + 微波电容　； 参考：《电子科技大学》2014年硕士论文

【摘要】：电容作为现代无线通信系统中的一类重要的基本元器件,决定着整个系统性能的好坏。在实际电路中电容一般用于旁路和去耦电路。随着通信系统“集成化、高速化”的发展趋势,对电容的“高频化、小型化”有了更高的要求。因此对微波电容的研究势在必行。本文主要分析高频下电容等效电路模型,研究电容器的特征参数(谐振频率、Q值)与物理尺寸、键合方式的关系,进而提取等效电路参数。然后利用低温共烧陶瓷工艺LTCC(Low Temperature Co-fired Ceramic)生产不同尺寸用于高频电路的微波电容,同时对工艺流程中的烧结和镀电极过程出现的不足之处做出改进。最后设计了一款用于测量微波电容测试校准的工具(TRL校准件),提高了微波电容测试的精度。全文主要内容包括:首先介绍微波电容的设计基础,阐述了电容器的品质因数和有效容值等基本概念,为建立等效电路模型奠定理论基础,进而给出了两种不同的等效模型。通过对电容器损耗的分析,可以得出电容器的损耗是随频率的升高而增大的。因此,提高电容器的谐振频率是以损失其品质因数为代价的。其次,以0.5mm×0.5mm×0.2mm电容为例,在HFSS中建立不同连接方式的电容物理模型,通过电容器的电流在同一端比在两端时的谐振频率高。电容器在实际电路中是以金丝键合方式来连接的,因此还分析了金丝线本身的微波性能,同时对使用金丝键合电容用π型等效电路做了拟合。最后,由于微波电容的工作频率较高,此时,接头到电容之间的寄生参量对测量结果影响较大。因此,为了提高测量精度,设计了一款TRL校准工具,它可以扣除从SMA接头到电容处对电容测试结果的影响。同时,还利用LTCC工艺生产出不同尺寸的微波电容,对烧结和镀金属流程出现的问题做出了改进,最后利用所设计的测试工具和校准工具进行准确测试。
[Abstract]:As an important basic component in modern wireless communication system, capacitance determines the performance of the whole system. In practical circuits, capacitors are generally used in bypass and decoupling circuits. With the development trend of "integration and high speed" of communication system, the high frequency and miniaturization of capacitance have higher requirements. Therefore, the study of microwave capacitance is imperative. In this paper, the capacitance equivalent circuit model at high frequency is analyzed, and the relationship between the characteristic parameters (resonant frequency Q value) and physical size and bonding mode is studied, and the equivalent circuit parameters are extracted. Then the microwave capacitors with different sizes for high frequency circuits were produced by using low temperature co-fired ceramic process LTCC(Low Temperature Co-fired Ceramici, and the shortcomings of sintering and electrode plating in the process were improved at the same time. Finally, a calibration tool for measuring microwave capacitance is designed, which improves the accuracy of microwave capacitance measurement. The main contents of this paper are as follows: firstly, the design basis of microwave capacitance is introduced, and the basic concepts such as quality factor and effective capacity of capacitor are expounded, which lays a theoretical foundation for the establishment of equivalent circuit model, and then gives two different equivalent models. By analyzing the loss of the capacitor, it can be concluded that the loss of the capacitor increases with the increase of frequency. Therefore, increasing the resonant frequency of the capacitor is at the expense of its quality factor. Secondly, taking 0.5mm 脳 0.5mm 脳 0.2mm capacitor as an example, the physical model of capacitance with different connection modes is established in HFSS. The resonant frequency of capacitor current at the same end is higher than that at both ends. The capacitor is connected by gold wire bonding in actual circuit. Therefore, the microwave performance of gold wire itself is also analyzed, and the 蟺 type equivalent circuit using gold wire bonding capacitor is fitted. Finally, because of the high frequency of microwave capacitors, the parasitic parameters between the connectors and the capacitors have a great influence on the measurement results. Therefore, in order to improve the measurement accuracy, a TRL calibration tool is designed, which can deduct the influence of the SMA connector to the capacitance test results. At the same time, microwave capacitors of different sizes were produced by LTCC process, and the problems in sintering and metal plating were improved. Finally, the designed test tools and calibration tools were used for accurate testing.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53
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本文编号：1936216