小型化双频定向耦合器的研究

发布时间：2018-05-25 10:52

本文选题：分支线耦合器 + 环形耦合器　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：随着无线通信技术的迅速发展,尤其是WLAN技术的发展,单频段通信已经不能满足系统要求,系统内的微波器件需要能够同时在两个甚至多个频段内工作。因此,为了与现代通信系统的发展相适应,小型化、宽带、多频带无源器件的设计成为必需。定向耦合器作为微波、毫米波系统中的关键器件,直接制约着整个系统的性能,因而小型化、多频带微带定向耦合器的研究也越来越受到重视。本文围绕双频定向耦合器的小型化开展研究工作,主要设计了两种常用的定向耦合器:分支线耦合器和环形耦合器。论文首先提出了一种新的小型化双频分支线耦合器。通过在传统分支线中间加载半椭圆环阻抗短截线实现了分支线耦合器的双频工作。半椭圆环阻抗短截线的引入增加了设计自由度,通过改变半椭圆环阻抗短截线的阻抗和长短轴比,有效地减小了半椭圆环阻抗短截线的纵向尺寸,因而可以把半椭圆环阻抗短截线折叠在耦合器的内部,实现了耦合器的小型化。基于半椭圆环阻抗短截线,本文设计了一个单节双频分支线耦合器,其工作频率为2.4/5.8GHz,具有良好的隔离度、耦合度。基于半椭圆环阻抗短截线,本文还设计了一个工作频率为2.2/5.4GHz的双节分支线耦合器,其在实现小型化的同时,还增加了分支线耦合器的工作带宽。与基于阶梯阻抗变换短截线的分支线耦合器相比,本文设计的耦合器尺寸分别减小了43%和30%,对这两个分支线耦合器进行实物加工,测量和仿真结果吻合良好,证明了设计的有效性。其次,对双频环形耦合器进行了设计。基于上面提到的半椭圆环阻抗短截线,采用与分支线耦合器相同的分析方法,通过在分支线上加载六个半椭圆环阻抗短截线,设计了一个环形耦合器,其工作频率为2.4/5.8GHz。为了进一步减小尺寸,本文提出了一种新的环形耦合器结构,即在分支线上加载两个半椭圆环阻抗短截线。此新型环形耦合器的工作频率为2.4/5.2GHz,且其性能良好。与加载六个半椭圆环阻抗短截线的环形耦合器相比,此环形耦合器的尺寸减小了66%。最后对新型环形耦合器进行了实物加工并测量,其实测结果与仿真结果基本吻合。
[Abstract]:With the rapid development of wireless communication technology, especially the development of WLAN technology, single-band communication can no longer meet the requirements of the system. Microwave devices in the system need to be able to work in two or more frequency bands at the same time. Therefore, in order to adapt to the development of modern communication system, miniaturization, broadband, multi-band passive device design is necessary. As a key device in microwave and millimeter-wave system, directional coupler is a direct constraint to the performance of the whole system, so miniaturization has been paid more and more attention to the research of multi-band microstrip directional coupler. This paper focuses on the miniaturization of dual-frequency directional couplers. Two kinds of directional couplers are designed: branched couplers and circular couplers. In this paper, a new miniaturized dual-frequency branch line coupler is proposed. The dual frequency operation of the branch line coupler is realized by loading the semi-elliptic loop impedance truncation line in the middle of the traditional branch line. The design degree of freedom is increased with the introduction of the semi-elliptic ring impedance truncation. By changing the impedance of the semi-elliptic ring impedance short cut line and the ratio of the long and short axis, the longitudinal dimension of the half-elliptic ring impedance short cut line is reduced effectively. Therefore, the semi-elliptic loop impedance truncation line can be folded inside the coupler to realize the miniaturization of the coupler. Based on the semi-elliptic loop impedance truncation, a single-section dual-frequency branch line coupler is designed. Its working frequency is 2.4 / 5.8 GHz, which has good isolation and coupling degree. Based on the semi-elliptic loop impedance truncation, a two-section branch line coupler with a working frequency of 2.2/5.4GHz is designed, which not only achieves miniaturization, but also increases the working bandwidth of the branch line coupler. Compared with the branch line coupler based on step impedance transform, the size of the coupler designed in this paper is reduced by 43% and 30%, respectively. The two branch line couplers are processed in kind, and the measured results are in good agreement with the simulation results. The validity of the design is proved. Secondly, the double frequency ring coupler is designed. Based on the semi-elliptic loop impedance truncation mentioned above and using the same analytical method as the branch line coupler, a ring coupler is designed by loading six half-elliptic loop impedance short sections on the branch line, the operating frequency of which is 2.4 / 5.8 GHz. In order to further reduce the size, a new ring coupler structure is proposed, in which two semi-elliptical loop impedance short sections are loaded on the branch line. The working frequency of the new ring coupler is 2.4 / 5.2 GHz, and its performance is good. Compared with the ring coupler with six semi-elliptic loop impedance truncated lines, the size of the ring coupler is reduced by 66%. Finally, the new ring coupler is manufactured and measured, and the measured results are in good agreement with the simulation results.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN622

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