蝶形单元电磁带隙.doc
约69页DOC格式手机打开展开
蝶形单元电磁带隙,摘要近年来，移动通信与个人通信业务进入到了一个飞速发展的时期。高性能和小型化的微波电路是下一代无线通信系统的关键技术之一，电磁带隙结构(electromagnetic band gap, ebg)的提出以及它在微波、毫米波领域的应用，为系统的小型化和高可靠性提供了新的方法。本文的主要工作是根据ebg结构的特点，分别讨论...
内容介绍
此文档由会员 违规屏蔽12 发布
摘 要
近年来，移动通信与个人通信业务进入到了一个飞速发展的时期。高性能和小型化的微波电路是下一代无线通信系统的关键技术之一，电磁带隙结构(Electromagnetic Band Gap, EBG)的提出以及它在微波、毫米波领域的应用，为系统的小型化和高可靠性提供了新的方法。本文的主要工作是根据EBG结构的特点，分别讨论了单层、双层蝶形单元EBG结构的频率特性，并用粒子群优化（Particle Swarm Optimization，PSO）算法对结构进行优化设计。
本文主要工作如下：
1. 研究了一种蝶形单元的EBG结构。通过微波双端口网络理论对EBG结构进行分析，得到它的频率特性。由仿真计算结果可以看出，该EBG结构的蝶形单元按照Hanning规律渐变时性能较好，此时－10dB带宽为2.87GHz，相对带宽为55%；而具有缺陷的EBG结构在阻带中形成一个具有一定带宽的通带，且通带的频率很容易调整。
2. 利用PSO算法对蝶形单元EBG结构进行优化设计，使其频率特性更好。在优化过程中，为克服粒子群算法存在的早熟收敛和搜索精度低等问题，模拟生物克隆选择中5%的B细胞自然消亡过程，在优化算法进化过程中基于混沌理论和变异原理设计了粒子更新算法，并按照模拟退火方法进行更新后粒子的选择。通过仿真计算可以看出，该电磁带隙结构具有良好的阻带性能和相对带宽，且优化后通带波纹明显减小且基本对称，频率特性较好。
3. 研究了一种双层EBG结构，其上层为蝶形单元结构，下层为接地板刻蚀圆孔结构，通过仿真实验确定了圆的半径及其与蝶形单元的相对位置。实验中为了减小通带波纹，将圆的面积按照Chebyshev函数渐变，使得双层EBG结构具有较好的频率特性。
4. 研究了一种双层EBG结构，其上层为蝶形单元结构，下层为接地板刻蚀圆环结构，利用PSO算法与HFSS软件相结合对其进行优化设计，优化后－10dB的相对带宽和阻带衰减值分别增加了22.69%和15.26%，通带波纹减小了76.76%，优化后结构的频率特性更好。
关键词 电磁带隙；蝶形单元；频率特性；粒子群优化
Abstract
The mobile communications and personal communications have been rapidly grown with wide applications in recent years. The microwave circuit with compact and high performance is one of the critical technologies in next generation wirelesse communication system. Electromagnetic bnad gap (EBG) and its applications in microwave and millimeter wave field present a new path for the communication system towards high compactness, performance and reliability. Based on the characteristics of EBG structure, the frequency chacteristics of single-layer and double-layer EBG structure with bow-tie units are discussed in this thesis respectively. And then particle swarm optimization (PSO) algorithm is used to optimize the structures.
The main research works are discussed as follows:
1. An EBG structure with bow-tie unit is researched in this thesis. Based on the theory of microwave 2-ports network, its frequency chacteristics is obtained. The simulaton results show that the performance of the EBG structure with bow-tie units is good when it tapers with hanning discipline. At this time, the bandwidth is about 2.87GHz at －10dB, and its relative bandwidth is 55%. The EBG structure with defect forms a passband with a certain bandwidth in the stopband, and the center frequency of passband may be adjusted easily.
2. The EBG structure with bow-tie units is optimized by using PSO algorithm. As we all know, the standard PSO has some shortcomings, such as premature convergence, searching precision lowness and so forth. In order to solve the problems, considering the simulation of natural death process of 5% B-cell in biology clone selection, this thesis proposes particles updating algorithm according to the theory of chaos and principle of mutation; and then selects the updated particles in terms of simulated annealing method. The simulation results show that the EBG structure with bow-tie units has a good stopband performance and large relative bandwidth. The passband ripples of the optimized EBG structure are very small and basically symmetrical. Frequency characteristic of the optimized EBG structure is very excellent.
3. A double-layer EBG structure is studied, including the bow-tie units etched on the upper layer and circles etched on the substrate. The radius of the circles and relative positions between circles and bow-tie cells are determined by simulation. For eliminating the passband ripples, the Chebyshev distribution is adopted to taper the area of the etched circles. This makes the frequency characteristics great.
4. A double-layer EBG structure is studied, including the bow-tie units etched on the upper layer and cirques etched on the substrate. PSO algorithm and the HFSS software are combined to optimize the sizes of the cirques. After optimizating, the relative bandwidth at －10dB and the attenuation of stopband are, respectively, increased 22.69% and 15.26%, and the passband ripples are reduced 76.76%. The frequency characteristics are very well after optimization.
Key Words Electromagnetic band gap; bow-tie unit; frequency characteristic; particle swarm optimization
目 录
摘 要 I
ABSTRACT III
第1章 绪论 1
1.1 课题的研究背景和选题意义 1
1.2 课题的国内外研究现状 2
1.2.1 电磁带隙结构的研究现状 2
1.2.2 粒子..
近年来，移动通信与个人通信业务进入到了一个飞速发展的时期。高性能和小型化的微波电路是下一代无线通信系统的关键技术之一，电磁带隙结构(Electromagnetic Band Gap, EBG)的提出以及它在微波、毫米波领域的应用，为系统的小型化和高可靠性提供了新的方法。本文的主要工作是根据EBG结构的特点，分别讨论了单层、双层蝶形单元EBG结构的频率特性，并用粒子群优化（Particle Swarm Optimization，PSO）算法对结构进行优化设计。
本文主要工作如下：
1. 研究了一种蝶形单元的EBG结构。通过微波双端口网络理论对EBG结构进行分析，得到它的频率特性。由仿真计算结果可以看出，该EBG结构的蝶形单元按照Hanning规律渐变时性能较好，此时－10dB带宽为2.87GHz，相对带宽为55%；而具有缺陷的EBG结构在阻带中形成一个具有一定带宽的通带，且通带的频率很容易调整。
2. 利用PSO算法对蝶形单元EBG结构进行优化设计，使其频率特性更好。在优化过程中，为克服粒子群算法存在的早熟收敛和搜索精度低等问题，模拟生物克隆选择中5%的B细胞自然消亡过程，在优化算法进化过程中基于混沌理论和变异原理设计了粒子更新算法，并按照模拟退火方法进行更新后粒子的选择。通过仿真计算可以看出，该电磁带隙结构具有良好的阻带性能和相对带宽，且优化后通带波纹明显减小且基本对称，频率特性较好。
3. 研究了一种双层EBG结构，其上层为蝶形单元结构，下层为接地板刻蚀圆孔结构，通过仿真实验确定了圆的半径及其与蝶形单元的相对位置。实验中为了减小通带波纹，将圆的面积按照Chebyshev函数渐变，使得双层EBG结构具有较好的频率特性。
4. 研究了一种双层EBG结构，其上层为蝶形单元结构，下层为接地板刻蚀圆环结构，利用PSO算法与HFSS软件相结合对其进行优化设计，优化后－10dB的相对带宽和阻带衰减值分别增加了22.69%和15.26%，通带波纹减小了76.76%，优化后结构的频率特性更好。
关键词 电磁带隙；蝶形单元；频率特性；粒子群优化
Abstract
The mobile communications and personal communications have been rapidly grown with wide applications in recent years. The microwave circuit with compact and high performance is one of the critical technologies in next generation wirelesse communication system. Electromagnetic bnad gap (EBG) and its applications in microwave and millimeter wave field present a new path for the communication system towards high compactness, performance and reliability. Based on the characteristics of EBG structure, the frequency chacteristics of single-layer and double-layer EBG structure with bow-tie units are discussed in this thesis respectively. And then particle swarm optimization (PSO) algorithm is used to optimize the structures.
The main research works are discussed as follows:
1. An EBG structure with bow-tie unit is researched in this thesis. Based on the theory of microwave 2-ports network, its frequency chacteristics is obtained. The simulaton results show that the performance of the EBG structure with bow-tie units is good when it tapers with hanning discipline. At this time, the bandwidth is about 2.87GHz at －10dB, and its relative bandwidth is 55%. The EBG structure with defect forms a passband with a certain bandwidth in the stopband, and the center frequency of passband may be adjusted easily.
2. The EBG structure with bow-tie units is optimized by using PSO algorithm. As we all know, the standard PSO has some shortcomings, such as premature convergence, searching precision lowness and so forth. In order to solve the problems, considering the simulation of natural death process of 5% B-cell in biology clone selection, this thesis proposes particles updating algorithm according to the theory of chaos and principle of mutation; and then selects the updated particles in terms of simulated annealing method. The simulation results show that the EBG structure with bow-tie units has a good stopband performance and large relative bandwidth. The passband ripples of the optimized EBG structure are very small and basically symmetrical. Frequency characteristic of the optimized EBG structure is very excellent.
3. A double-layer EBG structure is studied, including the bow-tie units etched on the upper layer and circles etched on the substrate. The radius of the circles and relative positions between circles and bow-tie cells are determined by simulation. For eliminating the passband ripples, the Chebyshev distribution is adopted to taper the area of the etched circles. This makes the frequency characteristics great.
4. A double-layer EBG structure is studied, including the bow-tie units etched on the upper layer and cirques etched on the substrate. PSO algorithm and the HFSS software are combined to optimize the sizes of the cirques. After optimizating, the relative bandwidth at －10dB and the attenuation of stopband are, respectively, increased 22.69% and 15.26%, and the passband ripples are reduced 76.76%. The frequency characteristics are very well after optimization.
Key Words Electromagnetic band gap; bow-tie unit; frequency characteristic; particle swarm optimization
目 录
摘 要 I
ABSTRACT III
第1章 绪论 1
1.1 课题的研究背景和选题意义 1
1.2 课题的国内外研究现状 2
1.2.1 电磁带隙结构的研究现状 2
1.2.2 粒子..
