【作者】 韩世虎；

【导师】 樊勇；

【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2007， 博士

【摘要】 在现代微波毫米波系统中，滤波器和双工器是重要部件之一，用于通道选择和信号分离，其性能的优劣直接影响整个通信系统的质量。低插损、小体积、高频率选择性、低成本和快速设计等成为滤波器和双工器的关键技术要求，而传统滤波器和设计方法很难适应现代发展的需要。广义切比雪夫滤波器具有尖锐的频率选择性，又可以平坦滤波器的群时延，还可以形成多频滤波器，因此在各种微波毫米波系统中得到广泛的应用。其设计灵活，仿真优化难度大。国内外学者运用多种数值算法对其进行全波建模，以便快速精确设计广义切比雪夫滤波器和波导双工器，其中，基于严格场理论的模式匹配法因其精度高、运算速度快等优点而得到国内外研究工作者的高度重视。本文将它运用于矩形波导接头中带通用圆柱杆的四口网络(本文简称：四口矩形结)、多阶梯矩形波导弯头和T—septum矩形波导接头的全波建模，有助于快速高效设计梳状广义切比雪夫滤波器、拐弯波导双工器、广义切比雪夫波导滤波器和双工器。在滤波器的物理结构实现上，一种新的基片集成波导技术广泛用于微波毫米波无源器件设计，它是通过在基片上打孔等效金属壁形成波导系统，其主要特性是低成本、小尺寸和易与平面电路集成。本文主要目的是研究广义切比雪夫滤波器拓扑结构、物理结构上可实现的耦合矩阵提取及其特性分析和基于模式匹配法全波建模四口矩形结、多阶梯矩形波导弯头、T—scptum矩形波导接头，最后，设计了一系列高性能的滤波器和双工器。主要工作概括如下：1系统研究了广义切比雪夫滤波器理论。广义切比雪夫滤波器是基于一种全耦合的等效电路模型，必须提取物理上可实现的耦合矩阵来应用于器件设计。本文首先讨论滤波器可实现的通用拓扑结构，然后提出一种混合算法用于提取广义切比雪夫滤波器源与负载直接耦合和源与负载不直接耦合的带通滤波器的耦合矩阵；还提取了传输零点同时位于带内和带外的多频带通滤波器的耦合矩阵，并采用传统方法综合广义切比雪夫带阻滤波器的耦合矩阵；最后，分析了广义切比雪夫滤波器时延特性并得出结论。2基于模式匹配法全波建模四口矩形结、多阶梯矩形波导弯头和T—septum矩形波导接头的关键技术研究。四口矩形结是设计多种微波无源器件的基本单元，如：广义切比雪夫梳状滤波器等，多阶梯矩形波导弯头和T—septum矩形波导接头是波导滤波器和双工器的基本单元。本文采用模式匹配法全波建模了这三种波导接头，并在建模过程中采用了奇偶模理论，简化了公式推导和程序编写，完善了原有的模式匹配法程序库。3利用所编写的电磁仿真程序和商业仿真软件，优化设计并加工了一系列微波滤波器和双工器。第五章运用HFSS仿真软件设计了梳状阶跃阻抗交叉耦合滤波器，采用自编程序设计了双频带通波导滤波器、拐弯波导双工器。第六章利用自编程序设计了几种较为新颖的基片集成波导滤波器，其中包括多频带阻滤波器、交叉耦合吸收式滤波器和带Triplet拓扑的广义切比雪夫平面双工器。多频带阻滤波器是基于提出的一种新的横向耦合网络，这种滤波器主要应用于宽频系统中。试验表明，器件的实测结果与仿真结果或理论曲线吻合很好。验证了本文设计方法、公式推导和程序编写的正确性。更多还原

【Abstract】 Filters and diplexers are important components for channel selection and signal separation in modern microwave and millimeter-wave systems. Their electrical performances are crucial for communication systems. The key requirements for filters and diplexers include low insertion loss, compact size, sharp frequency selectivity, low costs and quick design simultaneously. Traditional filtering functions and design methods can no longer keep up with the paces of microwave and millimeter-wave technique development.The generalized chebyshev filters have skirt selectivity, flatten the group delay and can be used to generate multiple-band filters. The attractive characteristics make them very popular in the microwave and millimeter-wave system. The filters have flexible design but are very difficult to simulate and optimize. Several numerical algorithms are applied to model the generalized chebyshev filters and diplexers by domestic and foreign researchers based on full-wave analysis. Designers pay much attention to the mode matching method because of its features of high precision and fast simulation speed in passive component design. Four-port network with partial height cylindrical objects in rectangular waveguide junctions (i.e., Four-port rectangular junctions), multiple-stepped rectangular waveguide bend and T-septum rectangular waveguide junction are modeled by full-wave mode matching method in order to quickly design the combline cross-coupled filter, corner waveguide diplexer, generalized chebysheve waveguide filters and diplexers with high efficiency in this paper. Substrate integrated waveguide (SIW) technique is widely applied to design the microwave and millimeter-wave devices. It is constructed by the metallized via holes on the substrate. This technique features low costs, compact size and is easily to be integrated with planar circuits.The purpose of this paper is to extract the coupling matrix of generalized chebyshev filter, model the four-port rectangular junctions, multiple-stepped rectangular waveguide bend and T-septum rectangular waveguide junction by full-wave methods and design generalized chebyshev filters and diplexers. The main works are as follows:1. Systematically research on the theory of generalized chebyshev filtersThe generalized chebyshev filters are based on the all-coupled model. The coupling matrix, which can be physically realized, should be extracted. A hybrid algorithm is presented for the extraction of coupling matrix of the generalized chebyshev filters with direct source-load coupling and indirect source-load coupling. The coupling matrix of multiple-band bandpass filters are extracted with transmission zeros both in the passband and in the stopband. The coupling matrix of generalized chebyshev bandstop filters are synthesized by traditional methods. At last, the group delay characteristics of bandpass filters are analyzed.2. The study of modeling of four-port rectangular junctions, multiple-stepped bend and T-septum junction by full-wave mode matching method.Four-port rectangular junctions are the key blocks in the design of passive devices such as: cross-coupled combline filters. Multiple stepped rectangular waveguide bend and T-septum rectangular waveguide junction are the key blocks in the design of waveguide filters and diplexers. The above-mentioned junctions and bend are modeled by full-wave mode matching method. The odd-even mode theory is adopted to simplify the deduction of formulation and computation codes in the process of modeling. The former computation codes are supplemented.3. A series of microwave filters and diplexers are designed by optimization and fabricated based on HFSS and the programs written by myself.A combline SIR cross-coupled filter is designed by HFSS. Cha.5 presented the design of dual-band bandpass filter and corner diplexer. Serval new components are designed in Cha.6 based on substrate integrated waveguide (SIW) technique such as: multiple-band bandstop filter, generalized chebyshev absorption filter and diplexer. The multiple-band bandstop filter is based on proposed transveral coupling network for broadband applications. Experimental results have proved the validity of the analysis, programming and design methods.更多还原