基于慢波结构的微波电路小型化研究

发布时间：2018-03-06 06:29

本文选题：小型化　切入点：谐波抑制　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着现代通信技术的快速发展,设备的小型化成为一个重要的发展趋势。在射频前端系统中,诸多的微波无源器件如耦合器、Butler矩阵等的小型化设计变得尤其关键。其次,高次谐波会严重影响系统的质量,干扰系统的正常工作。因此,如何在实现系统小型化的同时,抑制高次谐波也成为了一个亟待解决的问题。针对小型化问题,本文提出了一种具有高慢波因子的慢波结构,并将其应用到分支线耦合器和Butler矩阵的小型化设计中;其次,针对高次谐波问题,通过在慢波结缺陷地结构来抑制二次谐波,另外,调节慢波结构的尺寸参数,使其中的LC谐振器谐振在三次谐波频率上,从而实现了具有谐波抑制特性的慢波结构,并借助环形耦合器来验证该慢波结构的设计。本文的主要研究内容和创新如下:1、介绍了慢波结构的工作原理,并分析了其特性,给出了慢波结构的一些设计准则。同时分析了由慢波结构S参矩阵反演其特征阻抗和相位的计算方法。2、以蛇形线结构和交指结构为基础,结合其等效电路和慢波结构工作原理,利用两层PCB板的层压工艺,设计和加工了一个高慢波因子的慢波结构,电磁仿真和等效电路计算与测试结果基本吻合。利用该慢波结构,本文设计和制作了小型化的分支线耦合器和4 x 4 Butler矩阵。基于慢波结构的分支线耦合器尺寸为14 x 20 mm2,仅为传统结构大小的9%;基于慢波结构的4 x 4 Butler矩阵尺寸为76 x 39 mm2,仅为传统结构的5.8%。同时,分支线耦合器和4 x 4 Butler矩阵均具有良好的带宽、插损和相位特性。3、在高慢波因子慢波结构的基础上,在保证慢波结构小尺寸、带宽和损耗的前提下,通过慢波结构内部LC谐振器和螺旋型缺陷地结构引入传输零点,设计了具有二次、三系谐波抑制特性的慢波结构。将此慢波结构应用到环形耦合器,设计和加工的环形耦合器的尺寸为43x7 mm2,仅为传统结构的6%。同时,二次和三次谐波也被抑制到-25dB以下。4、为了控制成本和降低设计复杂度,设计了一个具有谐波抑制特性的单层慢波结构,并基于该单层慢波结构实现了小型化的环形耦合器,其尺寸为44.5 x 15.5 mm2,仅为传统结构的13.89%。测试结果表明,环形耦合器具有良好的回波、插损和相位特性,二次和三次谐波也均被抑制到-25dB以下。
[Abstract]:With the rapid development of modern communication technology, the miniaturization of devices becomes an important trend. In RF front-end systems, the miniaturization design of many microwave passive devices such as coupler and Butler matrix becomes particularly critical. High-order harmonics will seriously affect the quality of the system and interfere with the normal operation of the system. Therefore, how to reduce the high-order harmonics while realizing the miniaturization of the system has become a problem to be solved urgently. In this paper, a kind of slow wave structure with high slow wave factor is proposed and applied to the miniaturization design of branch line coupler and Butler matrix. In addition, by adjusting the dimension parameters of the slow wave structure, the LC resonator resonates on the third harmonic frequency, so that the slow wave structure with harmonic suppression characteristics is realized. The main contents and innovations of this paper are as follows: 1. The working principle of the slow wave structure is introduced, and its characteristics are analyzed. Some design criteria of slow wave structure are given. The calculation method of inversion of characteristic impedance and phase from S-parameter matrix of slow wave structure is analyzed. Based on the snake-like structure and intersecting structure, the equivalent circuit and the working principle of slow wave structure are combined. A slow wave structure with high slow-wave factor is designed and fabricated by using the laminating technology of two-layer PCB plate. The calculation results of electromagnetic simulation and equivalent circuit are in good agreement with the test results. In this paper, the miniaturized branch line coupler and 4 x 4 Butler matrix are designed and fabricated. The size of the branch line coupler based on slow wave structure is 14 x 20 mm 2, which is only 9 parts of the traditional structure, and the 4 x 4 Butler matrix ruler based on slow wave structure. An inch of 76 x 39 mm 2, which is only 5.8 of the traditional structure. At the same time, Both the branch line coupler and the 4 x 4 Butler matrix have good bandwidth, insertion loss and phase characteristics. On the basis of the slow wave structure with high slow wave factor, the small size, bandwidth and loss of the slow wave structure are guaranteed. A slow wave structure with the characteristics of second and third harmonic suppression is designed by introducing the LC resonator inside the slow wave structure and the helical defect ground structure at 00:00. The slow wave structure is applied to the ring coupler. The size of the designed and fabricated ring coupler is 43 x 7 mm 2, which is only 6 parts of the traditional structure. At the same time, the second and third harmonics are also suppressed below -25 dB .4. in order to control the cost and reduce the design complexity, A single-layer slow-wave structure with harmonic suppression characteristics is designed. Based on the single-layer slow-wave structure, a miniaturized ring coupler is realized. The size of the coupler is 44.5 x 15.5mm ~ 2, which is only 13.89 of the traditional structure. The ring coupler has good echo, insertion loss and phase characteristics, and the second and third harmonics are also suppressed below -25 dB.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN454

【参考文献】