【作者】 钱可伟；

【导师】 唐小宏；

【作者基本信息】 电子科技大学 ， 电路与系统， 2012， 博士

【摘要】 随着无线通信系统的不断发展，近年来崛起的低温共烧陶瓷技术（LTCC）由于其低成本、低介质损耗、多层布局、良好的导电导热率和高频高Q等特性被广泛应用于各种小型化、轻量化、高性能和高集成度的微波毫米波电路与系统。本论文基于平面交叉耦合滤波器和微带天线的基本理论，结合LTCC工艺的三维布局特性，提出了一系列多层结构的微带滤波器和天线设计方案。其中，滤波器具有小体积、高抑制度、宽频/双频、传输零点和谐振频率可调等特性；天线具有双频、双圆极化、紧凑的辐射面和体积等特点，具有广阔的应用前景。首先，本论文详细阐述了交叉耦合滤波器的基本原理，将耦合矩阵的优化设计转化为求目标函数最小值问题，提出适用于任意拓扑结构的遗传-Solvopt混合优化算法。以MATLAB作为研究平台，在滤波器设计实例中验证了优化算法的可行性。引入源和负载的耦合并提出一系列新型的滤波器拓扑结构，对它们的传输零点和响应曲线进行了详细设定和分析。介绍了N胞模块级联滤波器，其传输零点由每个N胞模块单独控制，然后根据所需阶数，选择模块之间的级联方式组成多阶级联滤波器。在准确实现传输零点的基础上，可兼顾良好的反射响应、较高的阻带抑制和矩形系数。所以N胞模块级联滤波器不仅拥有高阶滤波器的优良传输性能，其结构分析和实现还因基于独立模块而变得简单，并降低了仿真和加工可能带来的误差影响。其次，本论文研究了多种谐振滤波器，提出一系列基于LTCC技术的新型滤波器结构。利用LTCC的工艺特点设计多层交叉耦合阶跃阻抗谐振（SIR）滤波器，使得各谐振单元间的耦合方式从传统的平面转为立体，耦合度控制更灵活，体积更小。同时源-负载的耦合以及零度馈电方式的引入保证了阻带的高抑制度。设计了一系列三维结构的宽带带通和带阻滤波器，所有滤波器均由半集总的谐振单元组成，谐振单元中的电容由LTCC多层平板电容实现。传输零点的位置由各谐振单元参数单独控制，可实现带宽和阻带抑制度的自由调节。同时，利用这种半集总谐振单元的拓扑结构还设计了LTCC双通带滤波器，引入源-负载的垂直耦合来增加传输零点，进而提高选择性。各通带频率和传输零点位置由谐振元件值分别控制，灵活可调。接着，本论文研究了LTCC微带天线，提出了多种小型化结构设计。介绍了受扰动的双频双圆极化天线，通过调节不同层上的六边形辐射面和扰动切块面的大小，可在较宽频带内实现双频圆极化辐射特性。同时，在辐射面上使用矩形裂口，延长了辐射电流的有效路径。相当于在频率不变的情况下，进一步缩小了体积。然后在体积仅为3.2mm×1.6mm×2mm的LTCC基板内设计了多层折叠微带线来实现双频WLAN天线的功能。工作频点可通过调节各辐射层之间的耦合距离以及各层折叠线（谐振极子）自身的电长度来控制。辐射层之间的连接通过封端的方式实现，无通孔，工艺简单，成品率高。另外，研究发现使用非均匀间隔的折叠微带线可实现更宽的辐射带宽。更多还原

【Abstract】 With the development of wireless communication system, low temperature co-firedceramic (LTCC) technology has been widely used in many microwave/millimeter-wavecircuits with small size, light weight, good performance and high integration by itscharacteristics of low cost, low dielectric loss, multilayer layout, superior electric andthermal conductivity, high frequency and high Q value. Based on the basic theory ofplanar cross-coupled filter and microstrip antenna, this paper presents a series design ofmultilayer filter and antenna with LTCC3D structure. The filters have the features ofcompact size, high suppression, wide-band/dual-band, tunable transmission zeros andresonant frequency. And the antennas have the characteristics of dual-frequency, dualcircularly polarization, compact radiation area and volume. Thus there has anexpansively application prospects.First of all, the paper illustrates the elementary principles of cross coupled filterand reduces the matrix optimization problem to minimum value solution of objectivefunction. Genetic-Solvopt mixed algorithm, which is suitable for any topologicalstructure, is presented and its correctness is verified in filter design based on MATLABsoftware. A series of novel topological structures with source-load coupling is proposed,the transmission zeros and response curves are settled and analyzed in detail. Cascadefilters with N blocks modules are introduced, the transmission zeros of which arecontrolled by each module separately. The modules can be cascaded to form a highorder filter according to different cascade ways, while their transmission zeros are fixed.Thus cascade filter with N blocks modules has the properties of high stop-band rejection,good selectivity and reflection response. Meanwhile, the structure analysis andrealization could be simplified based on each single module, also the effect ofsimulation and fabrication error is reduced.Secondly, the paper presents some resonator filters with novel structure based onLTCC technology. Multilayer cross coupled SIR filter is designed with horizontal andvertical couplings, the size is more compact and the coupling element is easier to control. Meanwhile the introduction of source-load coupling and00feed structureguarantees the high suppression of stop band. Besides, a series of multilayeredwideband bandpass and bandstop filter is designed using semilumped resonators andmultilayer capacitors. The transmission zeros are controlled by each resonator separately,and the bandwidth as well as rejection level are free to adjust. Additionally, dual-bandbandpass filter with this semilumped resonator structure is also demonstrated.Source-load coupling in vertical direction is utilized to add transmission zeros andimprove the selectivity. The resonant frequencies and transmission zeros are flexiblytuned by elements of each resonator respectively.Thirdly, some LTCC microstrip antennas with miniaturized structure are discussed.Perturbed dual-band circularly polarized antenna with wide radiation bandwidth isrealized by tuning the area of radiation and perturbation pattern. Some inserted silts areutilized to meander the excited fundamental-mode patch surface current path, whicheffectively lowers the resonant frequency of the patch, thus the compactness of theproposed CP design is achieved. Besides, a novel compact WLAN antenna usingmeander striplines in three LTCC layers is completed, the volume of which is only3.2×1.6×2mm3. The resonant frequencies can be easily tuned by adjusting the innercoupling between different patterns and the length of the striplines (dipoles). Besides,the connection between different radiation layers is realized by end-coating, thus no viahole was used in this structure, which guarantees the easy fabrication and highproduction. Moreover, it is found that inhomogeneous spaced meander line createswider radiation bandwidth than homogeneous spaced one does.更多还原