基于新型平面结构的微波滤波器研究

发布时间：2019-04-03 06:09

【摘要】：伴随着现代无线通信系统的迅速发展,作为其中的关键部分,高性能宽带、多频带微波滤波器及平衡式滤波器已经成为了近年来电磁领域的研究热点。本论文结合理论研究和实际工程需求,提出了一系列新型的平面滤波结构,主要包含基于枝节加载谐振器的新型耦合结构、准集总参数混合型谐振器和枝节加载多模槽线结构,并探索其在单端式以及平衡式微波滤波器中的应用。首先,第二章中,提出了一种新型E形短路枝节加载谐振器的耦合方式,实现了谐振模式的独立控制,基于此实现了一款高性能四频带带通滤波器。提出了一款加载开路枝节耦合单元的多模谐振器,可通过调节枝节间耦合量,实现对奇模谐振频率的独立控制。基于此设计了一款高选择性陷波超宽带滤波器。此外,将源负载电耦合结构引入基片集成波导滤波器的设计中,在通带近端及远端阻带内产生数个额外零点,提高了滤波器的选择特性和谐波抑制能力。其次,第三章对不同边界条件下平行耦合馈电结构的特性进行了深入分析,并结合混合电磁耦合结构,实现了一系列具有高共模抑制能力和近端零点的平衡滤波器,其中二阶电路可在通带一侧产生一个近端零点,三阶电路可在通带二侧各产生一个近端零点,有效提高了通带选择性。然后,基于平衡式馈电网络,利用阶跃阻抗谐振器的基模和高次模,实现了一款双通带差分滤波器,同时具有良好的差模双通带滤波器响应和较高的共模抑制能力。第三,第四章提出了一种结构紧凑、谐振频率灵活可控的混合谐振器结构,。基于经典滤波器理论以及双通带滤波器实现条件,提出了一种二阶混合型谐振器滤波器的综合方法,可以同时实现对滤波器二个通带的带宽以及带内波纹的灵活控制。基于此,设计并实现了一款基于混合谐振器的二阶双通带滤波器。然后利用镜像方式研发了一款高性能差分式双通带滤波器。第四,第五章中对槽线结构的二种分析方法进行了介绍及对比。基于电磁对偶原理,提出了一系列基于多模槽线谐振器的平衡滤波器,其可在通带近端产生传输零点,实现了较高的通带选择性。同时利用槽线结构所具有的天然共模抑制特性,与微带结构的相比具有更为优异的共模抑制能力以及设计简单的优点。然后,基于单枝节加载的双模槽线谐振器,研发了一款双通带带通滤波器,随后引入平衡式馈电网络实现了一款平衡式双通带滤波器。最后,对本论文中的研究工作进行总结概括,并对今后的研究工作进行展望。
[Abstract]:With the rapid development of modern wireless communication systems, high-performance broadband, multi-band microwave filters and balanced filters have become the focus of research in electromagnetic field in recent years. In this paper, a series of novel planar filter structures are proposed, which include a new coupling structure based on branch-loaded resonator, a quasi-lumped parametric hybrid resonator and a branch-loaded multi-mode slot-line structure, combined with theoretical research and practical engineering requirements. Its application in single-ended and balanced microwave filters is also explored. Firstly, in the second chapter, a new coupling mode of E-shaped short-circuit branch-loaded resonator is proposed, and the independent control of resonant mode is realized. Based on this, a high-performance four-band-pass filter is implemented. A multi-mode resonator loaded with open branch coupling element is proposed. The frequency of odd mode resonance can be controlled independently by adjusting the coupling between branches. Based on this, a high-selective notch ultra-wideband filter is designed. In addition, the source load coupling structure is introduced into the design of the substrate integrated waveguide filter, and several additional zeros are generated in the near and far stop bands of the filter, which improves the selection characteristics and harmonic suppression ability of the filter. Secondly, in chapter 3, the characteristics of the parallel coupling feed structure under different boundary conditions are deeply analyzed, and a series of balanced filters with high common-mode rejection ability and near-zero point are realized by combining the hybrid electromagnetic coupling structure. The second-order circuit can produce a near-end zero on one side of the pass-band, and the third-order circuit can produce a near-end zero-point on each side of the pass-band, which effectively improves the pass-band selectivity. Then, based on the balanced feed network, a dual-band differential filter is realized by using the fundamental mode and high-order mode of the step impedance resonator. At the same time, the differential-mode dual-band filter has good response and high common-mode suppression ability. In chapter 3 and chapter 4, a hybrid resonator with compact structure and flexible and controllable resonant frequency is proposed. Based on the classical filter theory and the realization condition of the dual-pass band filter, a synthesis method of the second-order hybrid resonator filter is proposed, which can realize the flexible control of the band width and the intra-band ripple of the filter at the same time. Based on this, a second-order double-pass band filter based on hybrid resonator is designed and implemented. Then a high-performance differential dual-band filter is developed by mirror image method. The fourth and fifth chapter introduces and compares the two analytical methods of slot structure. Based on the principle of electromagnetic duality, a series of balanced filters based on multi-mode slot line resonators are proposed, which can generate transmission zeros at the near end of the pass band and achieve high pass-band selectivity. At the same time, compared with the microstrip structure, the slot-line structure has more excellent common-mode suppression ability and simple design advantage by using the natural common-mode suppression characteristic of the slot-line structure. Then, a dual-pass band-pass filter is developed based on the dual-mode slot-line resonator loaded with a single branch, and then a balanced dual-pass filter is implemented by introducing a balanced feed network. Finally, the research work in this paper is summarized, and the future research work is prospected.
【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN713

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